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Infectious disease and microbiology – Otitis externa
Otitis externa is an infection of the external auditory canal and is classified into four main types: acute localized, acute diffuse (swimmer’s ear), chronic, and invasive (malignant or necrotizing) otitis externa, the latter being a severe form that extends beyond the ear canal into surrounding soft tissue and bone. While most forms are common—affecting approximately 4 per 1000 people annually—the invasive form is rare but potentially life-threatening.
Risk factors vary by type. Hot, humid climates, frequent water exposure, and mechanical trauma (e.g., scratching or use of cotton swabs) predispose to acute diffuse otitis externa. In contrast, elderly patients, diabetics, and immunocompromised individuals are at higher risk for the invasive form. Preventive strategies include avoiding trauma to the ear canal and maintaining good diabetic control.
Pathophysiologically, disruption of the ear canal’s natural defenses—such as reduced acidity or decreased antimicrobial components like lysozyme and immunoglobulins (IgA, IgG)—facilitates microbial growth. Pseudomonas aeruginosa plays a key role, particularly in invasive disease, through increased expression of virulence factors such as exotoxins.
The etiology depends on the subtype. Acute localized infections (furuncles) are typically caused by Staphylococcus aureus. Acute diffuse otitis externa is most commonly due to Pseudomonas aeruginosa, along with other gram-negative bacteria, S. aureus, and occasionally fungi like Aspergillus. Chronic otitis externa is often related to persistent irritation from middle ear infections. Invasive otitis externa is most frequently caused by P. aeruginosa (>95% of cases), though other bacteria and fungi may be involved.
Clinically, patients with acute disease present with ear pain (otalgia), itching (pruritus), and sometimes discharge, with pain often worsened by manipulation of the auricle. Chronic cases tend to cause itching rather than pain. Invasive otitis externa presents more severely, with intense pain, purulent drainage, granulation tissue in the ear canal, and possible cranial nerve involvement (especially facial nerve palsy).
Diagnosis is primarily clinical and relies heavily on otoscopic examination. In invasive disease, laboratory findings may show a normal white blood cell count but elevated erythrocyte sedimentation rate. Imaging with CT (for bone involvement) and MRI (for soft tissue extension) is essential to assess disease extent. Deep tissue biopsy may be required to confirm diagnosis and exclude malignancy.
Treatment depends on severity. Topical antibiotic drops (often combined with corticosteroids) are the mainstay for uncomplicated cases, along with ear canal cleaning and moisture avoidance. Oral antibiotics are used if local therapy fails. Invasive otitis externa requires prolonged intravenous antipseudomonal antibiotics (6–8 weeks) such as ciprofloxacin, ceftazidime, cefepime, or carbapenems, along with meticulous canal care. Antifungal therapy is indicated when fungal pathogens are identified.
The prognosis is generally excellent for uncomplicated cases. In invasive otitis externa, outcomes have improved significantly, with up to 95% cure rates, although prognosis worsens with cranial nerve involvement, fungal infection, bilateral disease, or underlying immunosuppression.
Complications of invasive disease can be severe and include spread to the skull base, cranial nerve palsies, sigmoid sinus thrombosis, meningitis, and brain infection, making early recognition and aggressive treatment critical.
Otitis externa is an infection of the external auditory canal and is classified into four main types: acute localized, acute diffuse (swimmer’s ear), chronic, and invasive (malignant or necrotizing) otitis externa, the latter being a severe form that extends beyond the ear canal into surrounding soft tissue and bone. While most forms are common—affecting approximately 4 per 1000 people annually—the invasive form is rare but potentially life-threatening.
Risk factors vary by type. Hot, humid climates, frequent water exposure, and mechanical trauma (e.g., scratching or use of cotton swabs) predispose to acute diffuse otitis externa. In contrast, elderly patients, diabetics, and immunocompromised individuals are at higher risk for the invasive form. Preventive strategies include avoiding trauma to the ear canal and maintaining good diabetic control.
Pathophysiologically, disruption of the ear canal’s natural defenses—such as reduced acidity or decreased antimicrobial components like lysozyme and immunoglobulins (IgA, IgG)—facilitates microbial growth. Pseudomonas aeruginosa plays a key role, particularly in invasive disease, through increased expression of virulence factors such as exotoxins.
The etiology depends on the subtype. Acute localized infections (furuncles) are typically caused by Staphylococcus aureus. Acute diffuse otitis externa is most commonly due to Pseudomonas aeruginosa, along with other gram-negative bacteria, S. aureus, and occasionally fungi like Aspergillus. Chronic otitis externa is often related to persistent irritation from middle ear infections. Invasive otitis externa is most frequently caused by P. aeruginosa (>95% of cases), though other bacteria and fungi may be involved.
Clinically, patients with acute disease present with ear pain (otalgia), itching (pruritus), and sometimes discharge, with pain often worsened by manipulation of the auricle. Chronic cases tend to cause itching rather than pain. Invasive otitis externa presents more severely, with intense pain, purulent drainage, granulation tissue in the ear canal, and possible cranial nerve involvement (especially facial nerve palsy).
Diagnosis is primarily clinical and relies heavily on otoscopic examination. In invasive disease, laboratory findings may show a normal white blood cell count but elevated erythrocyte sedimentation rate. Imaging with CT (for bone involvement) and MRI (for soft tissue extension) is essential to assess disease extent. Deep tissue biopsy may be required to confirm diagnosis and exclude malignancy.
Treatment depends on severity. Topical antibiotic drops (often combined with corticosteroids) are the mainstay for uncomplicated cases, along with ear canal cleaning and moisture avoidance. Oral antibiotics are used if local therapy fails. Invasive otitis externa requires prolonged intravenous antipseudomonal antibiotics (6–8 weeks) such as ciprofloxacin, ceftazidime, cefepime, or carbapenems, along with meticulous canal care. Antifungal therapy is indicated when fungal pathogens are identified.
The prognosis is generally excellent for uncomplicated cases. In invasive otitis externa, outcomes have improved significantly, with up to 95% cure rates, although prognosis worsens with cranial nerve involvement, fungal infection, bilateral disease, or underlying immunosuppression.
Complications of invasive disease can be severe and include spread to the skull base, cranial nerve palsies, sigmoid sinus thrombosis, meningitis, and brain infection, making early recognition and aggressive treatment critical.
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Infectious disease and microbiology – Osteomyelitis
Osteomyelitis is an infection of bone, most commonly caused by bacteria and only rarely by fungi. It may present as acute disease, developing over days to weeks, or as chronic osteomyelitis, which evolves over months or years and is often associated with necrotic bone (sequestrum). The condition has an estimated incidence of 10–100 cases per 100,000 population and arises in a variety of clinical settings depending on host factors and route of infection.
Several risk factors predispose individuals to osteomyelitis, including diabetes mellitus (especially with foot ulcers), intravenous drug use, peripheral vascular disease, trauma, immunosuppression, and prior surgery or prosthetic implants. Certain organisms are associated with specific populations—for example, Salmonella in patients with sickle cell disease and Pseudomonas aeruginosa in intravenous drug users or puncture wounds through footwear. Preventive strategies emphasize good diabetic foot care and maintaining sterile surgical conditions, particularly for prosthetic procedures.
Infection reaches bone through three principal mechanisms: hematogenous spread, direct inoculation (trauma or surgery), or contiguous spread from nearby infected tissues. Once established, infection can involve the cortex, medullary cavity, and periosteum, leading to inflammation, abscess formation, and eventual bone necrosis. In children, infection commonly affects the metaphysis of long bones, whereas in adults, vertebral involvement is more typical.
The etiology is broad, with Staphylococcus aureus being the most common pathogen overall. Other causes include gram-negative organisms (e.g., Enterobacteriaceae), Pseudomonas, coagulase-negative staphylococci (especially in prosthetic infections), Mycobacterium tuberculosis, fungi such as Candida or endemic mycoses, and less commonly Brucella or organisms related to travel exposures.
Clinically, patients often present with localized bone pain, fever, swelling, and warmth over the affected area. Chronic cases may feature sinus tract formation with drainage. Recurrent or persistent cellulitis over a bony area should raise suspicion for underlying osteomyelitis. Diagnosis relies on a combination of laboratory testing and imaging, but the gold standard is bone biopsy for culture and histopathology, ideally obtained before antibiotic therapy. Blood cultures may identify the organism in up to 40% of acute cases, while inflammatory markers such as ESR are useful for monitoring disease activity.
Imaging plays a crucial role: plain X-rays may initially be normal, while MRI is highly sensitive, especially for spinal disease. CT scans can detect early cortical changes, and radionuclide scans are useful for early detection and identifying multifocal involvement. Advanced imaging such as PET may be helpful in chronic or unclear cases.
Management requires a combined medical and surgical approach. Prolonged antibiotic therapy (typically ≥6 weeks) is essential and should be tailored to the identified organism. For example, methicillin-susceptible S. aureus is treated with nafcillin or oxacillin, while MRSA requires vancomycin or alternative agents. Gram-negative infections are treated with fluoroquinolones or third-generation cephalosporins, and Pseudomonas infections require antipseudomonal agents. Importantly, surgical debridement of necrotic bone is often necessary, especially in chronic disease, and removal of infected prosthetic material may be required.
The prognosis is generally good for acute osteomyelitis with timely treatment but more guarded in chronic cases, where recurrence is common. Complications can be severe and include bone destruction, pathological fractures, epidural abscess with spinal cord compression, cranial neuropathies (in skull base involvement), amyloidosis, and even malignant transformation (Marjolin’s ulcer). Long-term follow-up is essential, as clinical and radiologic resolution may lag behind actual disease control.
Osteomyelitis is an infection of bone, most commonly caused by bacteria and only rarely by fungi. It may present as acute disease, developing over days to weeks, or as chronic osteomyelitis, which evolves over months or years and is often associated with necrotic bone (sequestrum). The condition has an estimated incidence of 10–100 cases per 100,000 population and arises in a variety of clinical settings depending on host factors and route of infection.
Several risk factors predispose individuals to osteomyelitis, including diabetes mellitus (especially with foot ulcers), intravenous drug use, peripheral vascular disease, trauma, immunosuppression, and prior surgery or prosthetic implants. Certain organisms are associated with specific populations—for example, Salmonella in patients with sickle cell disease and Pseudomonas aeruginosa in intravenous drug users or puncture wounds through footwear. Preventive strategies emphasize good diabetic foot care and maintaining sterile surgical conditions, particularly for prosthetic procedures.
Infection reaches bone through three principal mechanisms: hematogenous spread, direct inoculation (trauma or surgery), or contiguous spread from nearby infected tissues. Once established, infection can involve the cortex, medullary cavity, and periosteum, leading to inflammation, abscess formation, and eventual bone necrosis. In children, infection commonly affects the metaphysis of long bones, whereas in adults, vertebral involvement is more typical.
The etiology is broad, with Staphylococcus aureus being the most common pathogen overall. Other causes include gram-negative organisms (e.g., Enterobacteriaceae), Pseudomonas, coagulase-negative staphylococci (especially in prosthetic infections), Mycobacterium tuberculosis, fungi such as Candida or endemic mycoses, and less commonly Brucella or organisms related to travel exposures.
Clinically, patients often present with localized bone pain, fever, swelling, and warmth over the affected area. Chronic cases may feature sinus tract formation with drainage. Recurrent or persistent cellulitis over a bony area should raise suspicion for underlying osteomyelitis. Diagnosis relies on a combination of laboratory testing and imaging, but the gold standard is bone biopsy for culture and histopathology, ideally obtained before antibiotic therapy. Blood cultures may identify the organism in up to 40% of acute cases, while inflammatory markers such as ESR are useful for monitoring disease activity.
Imaging plays a crucial role: plain X-rays may initially be normal, while MRI is highly sensitive, especially for spinal disease. CT scans can detect early cortical changes, and radionuclide scans are useful for early detection and identifying multifocal involvement. Advanced imaging such as PET may be helpful in chronic or unclear cases.
Management requires a combined medical and surgical approach. Prolonged antibiotic therapy (typically ≥6 weeks) is essential and should be tailored to the identified organism. For example, methicillin-susceptible S. aureus is treated with nafcillin or oxacillin, while MRSA requires vancomycin or alternative agents. Gram-negative infections are treated with fluoroquinolones or third-generation cephalosporins, and Pseudomonas infections require antipseudomonal agents. Importantly, surgical debridement of necrotic bone is often necessary, especially in chronic disease, and removal of infected prosthetic material may be required.
The prognosis is generally good for acute osteomyelitis with timely treatment but more guarded in chronic cases, where recurrence is common. Complications can be severe and include bone destruction, pathological fractures, epidural abscess with spinal cord compression, cranial neuropathies (in skull base involvement), amyloidosis, and even malignant transformation (Marjolin’s ulcer). Long-term follow-up is essential, as clinical and radiologic resolution may lag behind actual disease control.
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Infectious disease and microbiology – Nocardiosis
Nocardiosis is an invasive opportunistic infection caused by Nocardia species, a group of aerobic, Gram-positive, branching filamentous bacteria belonging to the order Actinomycetales. First described in 1889, the disease may present as localized or disseminated infection, most commonly involving the lungs, but it can spread hematogenously—especially to the central nervous system (CNS)—and virtually any organ, including the skin, heart, kidneys, bones, and soft tissues.
Clinical manifestations range from pulmonary disease (acute, chronic, or subclinical) to brain abscesses, cellulitis, lymphocutaneous disease, actinomycetoma, and keratitis.
The infection is typically acquired through inhalation of organisms from soil or organic matter, making the lungs the primary site of infection, although traumatic skin inoculation or mucosal entry can also occur. There is no significant person-to-person transmission. Approximately 1,000 cases occur annually in the United States, with most involving pulmonary or systemic disease. Although nocardiosis can affect individuals of any age, it is more common in adults and males, and while many patients are immunocompromised, up to one-third are immunocompetent.
Major risk factors include conditions that impair cell-mediated immunity, such as HIV/AIDS, malignancy, organ transplantation, corticosteroid or TNF-alpha inhibitor therapy, Cushing’s syndrome, and chronic granulomatous disease. The most common pathogen is Nocardia asteroides, though other species like N. brasiliensis are associated with cutaneous disease, particularly in tropical regions.
Clinically, nocardiosis presents with nonspecific symptoms, especially in pulmonary disease, including productive cough, fever, weight loss, malaise, and occasionally dyspnea or hemoptysis. The disease may follow a chronic or relapsing course, and dissemination—particularly to the brain—may initially be asymptomatic. Cutaneous forms present as cellulitis, nodules, ulcers, or lymphocutaneous spread, while actinomycetoma causes chronic, deforming lesions with draining sinuses. CNS involvement typically manifests as brain abscesses, which are often multiple and indolent.
Diagnosis relies on microscopic and microbiological identification. Specimens such as sputum or pus reveal branching, beaded Gram-positive filaments, often requiring modified acid-fast staining. Cultures grow slowly and may take up to several weeks, forming chalky, pigmented colonies with a characteristic odor. Imaging studies such as chest X-ray or CT may show nodules, cavitations, or infiltrates, while brain imaging (CT/MRI) is essential when CNS involvement is suspected.
Treatment is prolonged and often requires combination antimicrobial therapy. First-line treatment includes trimethoprim-sulfamethoxazole (TMP-SMX), with alternatives such as amikacin, imipenem, ceftriaxone, or minocycline, depending on disease severity and susceptibility patterns. Therapy duration is typically 6–12 months, longer for CNS or immunocompromised cases. Surgical drainage or excision may be necessary for large abscesses or extensive disease.
Close follow-up is essential due to the risk of relapse or dissemination, even after apparent clinical improvement. Prognosis depends on immune status and extent of disease; mortality is relatively low in immunocompetent patients with localized pulmonary disease (~15%) but significantly higher in disseminated or CNS infections. Complications include brain abscess rupture, spinal cord compression, empyema, fistula formation, and widespread organ involvement, highlighting the need for early diagnosis and aggressive management.
Nocardiosis is an invasive opportunistic infection caused by Nocardia species, a group of aerobic, Gram-positive, branching filamentous bacteria belonging to the order Actinomycetales. First described in 1889, the disease may present as localized or disseminated infection, most commonly involving the lungs, but it can spread hematogenously—especially to the central nervous system (CNS)—and virtually any organ, including the skin, heart, kidneys, bones, and soft tissues.
Clinical manifestations range from pulmonary disease (acute, chronic, or subclinical) to brain abscesses, cellulitis, lymphocutaneous disease, actinomycetoma, and keratitis.
The infection is typically acquired through inhalation of organisms from soil or organic matter, making the lungs the primary site of infection, although traumatic skin inoculation or mucosal entry can also occur. There is no significant person-to-person transmission. Approximately 1,000 cases occur annually in the United States, with most involving pulmonary or systemic disease. Although nocardiosis can affect individuals of any age, it is more common in adults and males, and while many patients are immunocompromised, up to one-third are immunocompetent.
Major risk factors include conditions that impair cell-mediated immunity, such as HIV/AIDS, malignancy, organ transplantation, corticosteroid or TNF-alpha inhibitor therapy, Cushing’s syndrome, and chronic granulomatous disease. The most common pathogen is Nocardia asteroides, though other species like N. brasiliensis are associated with cutaneous disease, particularly in tropical regions.
Clinically, nocardiosis presents with nonspecific symptoms, especially in pulmonary disease, including productive cough, fever, weight loss, malaise, and occasionally dyspnea or hemoptysis. The disease may follow a chronic or relapsing course, and dissemination—particularly to the brain—may initially be asymptomatic. Cutaneous forms present as cellulitis, nodules, ulcers, or lymphocutaneous spread, while actinomycetoma causes chronic, deforming lesions with draining sinuses. CNS involvement typically manifests as brain abscesses, which are often multiple and indolent.
Diagnosis relies on microscopic and microbiological identification. Specimens such as sputum or pus reveal branching, beaded Gram-positive filaments, often requiring modified acid-fast staining. Cultures grow slowly and may take up to several weeks, forming chalky, pigmented colonies with a characteristic odor. Imaging studies such as chest X-ray or CT may show nodules, cavitations, or infiltrates, while brain imaging (CT/MRI) is essential when CNS involvement is suspected.
Treatment is prolonged and often requires combination antimicrobial therapy. First-line treatment includes trimethoprim-sulfamethoxazole (TMP-SMX), with alternatives such as amikacin, imipenem, ceftriaxone, or minocycline, depending on disease severity and susceptibility patterns. Therapy duration is typically 6–12 months, longer for CNS or immunocompromised cases. Surgical drainage or excision may be necessary for large abscesses or extensive disease.
Close follow-up is essential due to the risk of relapse or dissemination, even after apparent clinical improvement. Prognosis depends on immune status and extent of disease; mortality is relatively low in immunocompetent patients with localized pulmonary disease (~15%) but significantly higher in disseminated or CNS infections. Complications include brain abscess rupture, spinal cord compression, empyema, fistula formation, and widespread organ involvement, highlighting the need for early diagnosis and aggressive management.
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Infectious disease and microbiology – Neuropathies, infectious
Infectious neuropathies refer to inflammation or dysfunction of peripheral nerves caused by infectious agents or their toxins, including viruses, bacteria, parasites, and toxin-mediated mechanisms. A key example is Guillain-Barré syndrome (GBS), an immune-mediated neuropathy often triggered by a preceding infection. GBS has an incidence of approximately 1.2–3 cases per 100,000 people and can occur at any age, with peaks in young adults and older individuals. Risk factors vary depending on the cause and include immunosuppression (e.g., HIV/AIDS), advanced age, and exposure to endemic infections such as Lyme disease, leprosy, or Chagas disease. Preventive measures include vaccination (e.g., zoster, rabies, tetanus) and, in specific situations like tick exposure, prophylactic antibiotics.
The pathophysiology differs by condition but often involves either direct infection of nerve tissue or immune-mediated damage. In GBS, a prior infection triggers an immune response that cross-reacts with peripheral nerve components, leading to demyelination (most common) or axonal injury. Infectious causes include viruses such as herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), and HIV; bacteria such as Borrelia burgdorferi (Lyme disease) and Mycobacterium leprae (leprosy); parasites like Trypanosoma cruzi; and toxins from organisms such as Clostridium botulinum and Corynebacterium diphtheriae. Additionally, many cases of GBS are preceded by infections like Campylobacter jejuni, respiratory viruses, or gastrointestinal illnesses.
Clinical presentation depends on the underlying cause. Viral neuropathies often present with pain and dermatomal rashes, as seen in herpes zoster, or progressive sensory and motor deficits, as in CMV or HIV-related neuropathies. Bacterial causes such as Lyme disease may produce cranial nerve palsies, meningitis, or radiculopathy, while leprosy leads to sensory loss and nerve thickening. Toxin-mediated neuropathies have distinctive features, such as descending paralysis in botulism or muscle spasms in tetanus. In contrast, GBS typically begins with ascending symmetric weakness starting in the lower limbs, progressing over days to weeks and potentially involving respiratory muscles and autonomic dysfunction.
Diagnosis relies on clinical evaluation supported by laboratory and imaging studies. Tests may include detection of viral DNA (e.g., CMV in cerebrospinal fluid), serologic testing for Lyme disease, toxin identification in suspected botulism, and cerebrospinal fluid analysis in GBS, which classically shows elevated protein with normal cell count. Imaging such as MRI may demonstrate nerve root enhancement, while nerve conduction studies help assess the extent of nerve involvement.
Management is directed at the underlying cause. Antiviral therapy (e.g., acyclovir for HSV/VZV, ganciclovir for CMV) is used for viral infections, while bacterial causes like Lyme disease are treated with doxycycline or ceftriaxone. Toxin-mediated conditions require antitoxins and supportive care. For GBS, early treatment with plasmapheresis or intravenous immunoglobulin (IVIG) is essential to reduce disease severity and duration. Supportive care, including monitoring for respiratory failure, managing autonomic instability, and rehabilitation, plays a critical role in recovery.
Complications can be significant, particularly in GBS, where patients may experience residual neurologic deficits, recurrence, or prolonged disability. Early recognition and prompt management are crucial to improving outcomes and reducing long-term morbidity.
Infectious neuropathies refer to inflammation or dysfunction of peripheral nerves caused by infectious agents or their toxins, including viruses, bacteria, parasites, and toxin-mediated mechanisms. A key example is Guillain-Barré syndrome (GBS), an immune-mediated neuropathy often triggered by a preceding infection. GBS has an incidence of approximately 1.2–3 cases per 100,000 people and can occur at any age, with peaks in young adults and older individuals. Risk factors vary depending on the cause and include immunosuppression (e.g., HIV/AIDS), advanced age, and exposure to endemic infections such as Lyme disease, leprosy, or Chagas disease. Preventive measures include vaccination (e.g., zoster, rabies, tetanus) and, in specific situations like tick exposure, prophylactic antibiotics.
The pathophysiology differs by condition but often involves either direct infection of nerve tissue or immune-mediated damage. In GBS, a prior infection triggers an immune response that cross-reacts with peripheral nerve components, leading to demyelination (most common) or axonal injury. Infectious causes include viruses such as herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), and HIV; bacteria such as Borrelia burgdorferi (Lyme disease) and Mycobacterium leprae (leprosy); parasites like Trypanosoma cruzi; and toxins from organisms such as Clostridium botulinum and Corynebacterium diphtheriae. Additionally, many cases of GBS are preceded by infections like Campylobacter jejuni, respiratory viruses, or gastrointestinal illnesses.
Clinical presentation depends on the underlying cause. Viral neuropathies often present with pain and dermatomal rashes, as seen in herpes zoster, or progressive sensory and motor deficits, as in CMV or HIV-related neuropathies. Bacterial causes such as Lyme disease may produce cranial nerve palsies, meningitis, or radiculopathy, while leprosy leads to sensory loss and nerve thickening. Toxin-mediated neuropathies have distinctive features, such as descending paralysis in botulism or muscle spasms in tetanus. In contrast, GBS typically begins with ascending symmetric weakness starting in the lower limbs, progressing over days to weeks and potentially involving respiratory muscles and autonomic dysfunction.
Diagnosis relies on clinical evaluation supported by laboratory and imaging studies. Tests may include detection of viral DNA (e.g., CMV in cerebrospinal fluid), serologic testing for Lyme disease, toxin identification in suspected botulism, and cerebrospinal fluid analysis in GBS, which classically shows elevated protein with normal cell count. Imaging such as MRI may demonstrate nerve root enhancement, while nerve conduction studies help assess the extent of nerve involvement.
Management is directed at the underlying cause. Antiviral therapy (e.g., acyclovir for HSV/VZV, ganciclovir for CMV) is used for viral infections, while bacterial causes like Lyme disease are treated with doxycycline or ceftriaxone. Toxin-mediated conditions require antitoxins and supportive care. For GBS, early treatment with plasmapheresis or intravenous immunoglobulin (IVIG) is essential to reduce disease severity and duration. Supportive care, including monitoring for respiratory failure, managing autonomic instability, and rehabilitation, plays a critical role in recovery.
Complications can be significant, particularly in GBS, where patients may experience residual neurologic deficits, recurrence, or prolonged disability. Early recognition and prompt management are crucial to improving outcomes and reducing long-term morbidity.
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Infectious disease and microbiology – Necrotizing soft-tissue infections
Necrotizing soft-tissue infections (NSTIs) are rapidly progressive, life-threatening infections that involve the fascia and may extend to muscles, leading to extensive tissue destruction. They usually arise after a break in the skin, such as trauma, surgery, or even minor events like insect bites, although in many cases no clear initiating factor is identified. Clinically, they may present as necrotizing cellulitis, necrotizing fasciitis, or pyomyositis, and they are associated with high mortality rates exceeding 20%, often reaching around one-third of cases.
The incidence of NSTIs has been increasing, and although still uncommon, most clinicians will encounter at least one case during their practice. Risk factors include immunocompromised states, particularly diabetes mellitus and peripheral vascular disease, as well as obesity, chronic liver or renal disease, HIV infection, intravenous drug use, older age, and frequent hospitalizations. Certain populations, such as athletes or institutionalized individuals, are more prone to infections caused by community-associated MRSA.
Pathophysiologically, bacteria invade subcutaneous tissues and spread rapidly along fascial planes. The production of toxins and enzymes leads to local ischemia, impaired immune response, and widespread necrosis, allowing the infection to advance quickly. Most cases are polymicrobial (Type 1), involving a mixture of aerobic and anaerobic organisms, while others are monomicrobial (Types 2 and 3), commonly caused by Group A Streptococcus, Staphylococcus aureus, or Clostridium species.
Clinically, early symptoms may appear deceptively mild, with pain, erythema, swelling, and tachycardia, but the hallmark is pain out of proportion to physical findings. As the disease progresses, patients develop skin discoloration, bullae, crepitus, anesthesia, and systemic signs such as fever, hypotension, and shock, often rapidly progressing to sepsis and multi-organ failure. Diagnosis is primarily clinical, and urgent surgical exploration remains the gold standard, as delays can be fatal. Laboratory findings and scoring systems such as the LRINEC score may support suspicion, while imaging (CT or MRI) can reveal fascial thickening or gas in tissues but should not delay treatment.
Management requires immediate and aggressive intervention, combining broad-spectrum intravenous antibiotics with early surgical debridement, which is the most critical factor in reducing mortality. Empiric antibiotic therapy should cover gram-positive, gram-negative, and anaerobic organisms, with adjustments based on culture results. Repeated surgical exploration is often necessary, and in severe cases, amputation may be required. Patients typically require intensive care support, including fluid resuscitation, hemodynamic stabilization, and nutritional support.
Despite advances in management, prognosis remains serious. Mortality has improved with early recognition and aggressive treatment but remains high, and survivors often face significant morbidity. Complications include sepsis, acute respiratory distress syndrome, renal failure, nosocomial infections, and limb loss, highlighting the importance of prompt diagnosis and multidisciplinary management.
Necrotizing soft-tissue infections (NSTIs) are rapidly progressive, life-threatening infections that involve the fascia and may extend to muscles, leading to extensive tissue destruction. They usually arise after a break in the skin, such as trauma, surgery, or even minor events like insect bites, although in many cases no clear initiating factor is identified. Clinically, they may present as necrotizing cellulitis, necrotizing fasciitis, or pyomyositis, and they are associated with high mortality rates exceeding 20%, often reaching around one-third of cases.
The incidence of NSTIs has been increasing, and although still uncommon, most clinicians will encounter at least one case during their practice. Risk factors include immunocompromised states, particularly diabetes mellitus and peripheral vascular disease, as well as obesity, chronic liver or renal disease, HIV infection, intravenous drug use, older age, and frequent hospitalizations. Certain populations, such as athletes or institutionalized individuals, are more prone to infections caused by community-associated MRSA.
Pathophysiologically, bacteria invade subcutaneous tissues and spread rapidly along fascial planes. The production of toxins and enzymes leads to local ischemia, impaired immune response, and widespread necrosis, allowing the infection to advance quickly. Most cases are polymicrobial (Type 1), involving a mixture of aerobic and anaerobic organisms, while others are monomicrobial (Types 2 and 3), commonly caused by Group A Streptococcus, Staphylococcus aureus, or Clostridium species.
Clinically, early symptoms may appear deceptively mild, with pain, erythema, swelling, and tachycardia, but the hallmark is pain out of proportion to physical findings. As the disease progresses, patients develop skin discoloration, bullae, crepitus, anesthesia, and systemic signs such as fever, hypotension, and shock, often rapidly progressing to sepsis and multi-organ failure. Diagnosis is primarily clinical, and urgent surgical exploration remains the gold standard, as delays can be fatal. Laboratory findings and scoring systems such as the LRINEC score may support suspicion, while imaging (CT or MRI) can reveal fascial thickening or gas in tissues but should not delay treatment.
Management requires immediate and aggressive intervention, combining broad-spectrum intravenous antibiotics with early surgical debridement, which is the most critical factor in reducing mortality. Empiric antibiotic therapy should cover gram-positive, gram-negative, and anaerobic organisms, with adjustments based on culture results. Repeated surgical exploration is often necessary, and in severe cases, amputation may be required. Patients typically require intensive care support, including fluid resuscitation, hemodynamic stabilization, and nutritional support.
Despite advances in management, prognosis remains serious. Mortality has improved with early recognition and aggressive treatment but remains high, and survivors often face significant morbidity. Complications include sepsis, acute respiratory distress syndrome, renal failure, nosocomial infections, and limb loss, highlighting the importance of prompt diagnosis and multidisciplinary management.
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Infectious disease and microbiology – Myositis
Myositis is an inflammatory condition of skeletal muscles that may arise from infectious causes—including bacteria, viruses, fungi, parasites, and mycobacteria—or from noninfectious conditions. A specific form, pyomyositis, refers to a hematogenous bacterial infection of muscle that frequently leads to abscess formation, whereas acute bacterial myositis involves diffuse muscle infection without abscess. The epidemiology varies depending on the causative organism, but pyomyositis is relatively rare in temperate regions and more common in tropical areas, where it may account for a notable proportion of hospital admissions. Risk factors include immunocompromised states such as HIV infection, chronic illnesses like diabetes and malignancy, alcoholism, trauma, surgery, obesity, and residence in tropical climates.
The pathophysiology often involves muscle injury or trauma, which may create a susceptible environment for infection due to local infarction or hemorrhage. A wide range of pathogens can cause myositis: viral agents such as influenza, HIV, and herpes viruses; parasitic organisms like Trichinella spiralis, Toxoplasma gondii, and Echinococcus; and bacterial pathogens, most notably Staphylococcus aureus, which accounts for the majority of pyomyositis cases. Other bacterial causes include streptococci, clostridia (leading to gas gangrene), and mixed aerobic and anaerobic organisms. Fungal infections and infections related to aquatic exposure (e.g., Aeromonas hydrophila, Vibrio vulnificus) are less common but clinically important.
Clinically, myositis often presents insidiously with localized muscle pain and fever, progressing to swelling, induration, and marked tenderness. Deep muscle infections may lack overlying skin changes, making diagnosis challenging. In advanced cases, findings such as crepitus, malodorous discharge, hemorrhagic bullae, or systemic signs of sepsis may appear. Laboratory evaluation typically shows leukocytosis and elevated muscle enzymes, while cultures from deep tissue or aspirated material are essential for identifying the causative organism. Imaging studies such as CT or MRI help determine the extent of muscle involvement and detect abscess formation, while ultrasound can assist in emergency settings.
Management usually requires a combined medical and surgical approach, particularly for bacterial myositis. Abscesses should be drained, and empiric antibiotic therapy should cover common pathogens such as S. aureus, with adjustments based on culture results. Severe infections, such as those caused by streptococci or clostridia, require urgent surgical debridement and high-dose antibiotics, often including penicillin and clindamycin. Treatment of parasitic infections depends on the specific organism, while viral myositis is generally managed supportively. Additional therapies, such as hyperbaric oxygen for clostridial infections or immunoglobulin in toxic shock, may be indicated in selected cases.
Patients often require hospitalization, especially in bacterial or severe parasitic cases, with close monitoring and supportive care. Despite treatment, prognosis can be serious in severe infections, particularly those caused by streptococci or clostridia, which carry high mortality rates. Potential complications include bacteremia, septic shock, limb necrosis, toxic shock syndrome, and death, underscoring the importance of early recognition and aggressive management.
Myositis is an inflammatory condition of skeletal muscles that may arise from infectious causes—including bacteria, viruses, fungi, parasites, and mycobacteria—or from noninfectious conditions. A specific form, pyomyositis, refers to a hematogenous bacterial infection of muscle that frequently leads to abscess formation, whereas acute bacterial myositis involves diffuse muscle infection without abscess. The epidemiology varies depending on the causative organism, but pyomyositis is relatively rare in temperate regions and more common in tropical areas, where it may account for a notable proportion of hospital admissions. Risk factors include immunocompromised states such as HIV infection, chronic illnesses like diabetes and malignancy, alcoholism, trauma, surgery, obesity, and residence in tropical climates.
The pathophysiology often involves muscle injury or trauma, which may create a susceptible environment for infection due to local infarction or hemorrhage. A wide range of pathogens can cause myositis: viral agents such as influenza, HIV, and herpes viruses; parasitic organisms like Trichinella spiralis, Toxoplasma gondii, and Echinococcus; and bacterial pathogens, most notably Staphylococcus aureus, which accounts for the majority of pyomyositis cases. Other bacterial causes include streptococci, clostridia (leading to gas gangrene), and mixed aerobic and anaerobic organisms. Fungal infections and infections related to aquatic exposure (e.g., Aeromonas hydrophila, Vibrio vulnificus) are less common but clinically important.
Clinically, myositis often presents insidiously with localized muscle pain and fever, progressing to swelling, induration, and marked tenderness. Deep muscle infections may lack overlying skin changes, making diagnosis challenging. In advanced cases, findings such as crepitus, malodorous discharge, hemorrhagic bullae, or systemic signs of sepsis may appear. Laboratory evaluation typically shows leukocytosis and elevated muscle enzymes, while cultures from deep tissue or aspirated material are essential for identifying the causative organism. Imaging studies such as CT or MRI help determine the extent of muscle involvement and detect abscess formation, while ultrasound can assist in emergency settings.
Management usually requires a combined medical and surgical approach, particularly for bacterial myositis. Abscesses should be drained, and empiric antibiotic therapy should cover common pathogens such as S. aureus, with adjustments based on culture results. Severe infections, such as those caused by streptococci or clostridia, require urgent surgical debridement and high-dose antibiotics, often including penicillin and clindamycin. Treatment of parasitic infections depends on the specific organism, while viral myositis is generally managed supportively. Additional therapies, such as hyperbaric oxygen for clostridial infections or immunoglobulin in toxic shock, may be indicated in selected cases.
Patients often require hospitalization, especially in bacterial or severe parasitic cases, with close monitoring and supportive care. Despite treatment, prognosis can be serious in severe infections, particularly those caused by streptococci or clostridia, which carry high mortality rates. Potential complications include bacteremia, septic shock, limb necrosis, toxic shock syndrome, and death, underscoring the importance of early recognition and aggressive management.
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Infectious disease and microbiology – Myocarditis
Myocarditis is an inflammatory condition of the heart muscle (myocardium) that can result from a wide range of infectious agents, immune-mediated mechanisms, or external toxins. It may occur due to direct infection of cardiac tissue or from an immune response in which antibodies cross-react with myocardial cells, leading to damage. Although relatively uncommon, with an estimated incidence of 1–10 cases per 100,000 individuals, myocarditis is clinically significant because it contributes to up to 12% of sudden cardiac deaths in adolescents and young adults, affecting young males. Its true prevalence is difficult to determine because presentations range from mild, self-limited illness to severe heart failure or sudden death.
The disease is associated with numerous infectious causes, most commonly viral pathogens such as enteroviruses (especially Coxsackie B), adenovirus, influenza, cytomegalovirus, Epstein-Barr virus, HIV, and others. Bacterial, rickettsial, spirochetal, fungal, protozoal, and parasitic infections may also lead to myocarditis. Notably, Trypanosoma cruzi (Chagas disease) and HIV are important contributors in certain populations. Noninfectious triggers such as toxins, drugs, and systemic inflammatory diseases can also play a role. Immunocompromised individuals are at increased risk, and vaccination against viral pathogens may help reduce incidence.
Pathophysiologically, myocardial injury results from a combination of direct cytotoxic effects of pathogens, immune-mediated inflammation, cytokine release (e.g., tumor necrosis factor-alpha), and apoptosis of cardiac cells, all of which impair cardiac function.
Clinically, patients often report a recent viral-like illness with fever, malaise, or respiratory symptoms, followed by chest pain, palpitations, shortness of breath, or syncope. In some cases, myocarditis mimics acute myocardial infarction, while in others it presents later as chronic heart failure. Physical examination may reveal tachycardia, arrhythmias, signs of heart failure, or an S3 gallop, along with systemic features depending on the underlying cause.
Diagnosis involves a combination of laboratory testing, imaging, and sometimes biopsy. Laboratory findings may include leukocytosis, elevated inflammatory markers, and increased cardiac enzymes such as troponin. Imaging studies—especially echocardiography and cardiac MRI—help assess cardiac function and inflammation. Electrocardiography often shows nonspecific changes or conduction abnormalities. The gold standard for diagnosis is endomyocardial biopsy, which demonstrates inflammatory infiltration and myocardial necrosis, although it carries procedural risks and may yield false negatives.
Management is largely supportive, focusing on treatment of heart failure with medications such as diuretics, ACE inhibitors, and beta-blockers. Specific antimicrobial or antiviral therapy is used when an identifiable cause is present. In severe cases, advanced supportive measures such as ventricular assist devices or extracorporeal membrane oxygenation may be required, and cardiac transplantation may be considered in refractory cases. Adjunctive therapies such as intravenous immunoglobulin or immunosuppressive agents may be used selectively.
Follow-up care includes gradual rehabilitation, serial cardiac monitoring, and repeat imaging, with restrictions on physical activity during recovery. Long-term outcomes vary: some patients recover completely, while others develop complications such as dilated cardiomyopathy, arrhythmias, heart block, or cardiogenic shock. Early recognition and appropriate management are essential to improve prognosis and reduce the risk of serious complications, including sudden cardiac death.
Myocarditis is an inflammatory condition of the heart muscle (myocardium) that can result from a wide range of infectious agents, immune-mediated mechanisms, or external toxins. It may occur due to direct infection of cardiac tissue or from an immune response in which antibodies cross-react with myocardial cells, leading to damage. Although relatively uncommon, with an estimated incidence of 1–10 cases per 100,000 individuals, myocarditis is clinically significant because it contributes to up to 12% of sudden cardiac deaths in adolescents and young adults, affecting young males. Its true prevalence is difficult to determine because presentations range from mild, self-limited illness to severe heart failure or sudden death.
The disease is associated with numerous infectious causes, most commonly viral pathogens such as enteroviruses (especially Coxsackie B), adenovirus, influenza, cytomegalovirus, Epstein-Barr virus, HIV, and others. Bacterial, rickettsial, spirochetal, fungal, protozoal, and parasitic infections may also lead to myocarditis. Notably, Trypanosoma cruzi (Chagas disease) and HIV are important contributors in certain populations. Noninfectious triggers such as toxins, drugs, and systemic inflammatory diseases can also play a role. Immunocompromised individuals are at increased risk, and vaccination against viral pathogens may help reduce incidence.
Pathophysiologically, myocardial injury results from a combination of direct cytotoxic effects of pathogens, immune-mediated inflammation, cytokine release (e.g., tumor necrosis factor-alpha), and apoptosis of cardiac cells, all of which impair cardiac function.
Clinically, patients often report a recent viral-like illness with fever, malaise, or respiratory symptoms, followed by chest pain, palpitations, shortness of breath, or syncope. In some cases, myocarditis mimics acute myocardial infarction, while in others it presents later as chronic heart failure. Physical examination may reveal tachycardia, arrhythmias, signs of heart failure, or an S3 gallop, along with systemic features depending on the underlying cause.
Diagnosis involves a combination of laboratory testing, imaging, and sometimes biopsy. Laboratory findings may include leukocytosis, elevated inflammatory markers, and increased cardiac enzymes such as troponin. Imaging studies—especially echocardiography and cardiac MRI—help assess cardiac function and inflammation. Electrocardiography often shows nonspecific changes or conduction abnormalities. The gold standard for diagnosis is endomyocardial biopsy, which demonstrates inflammatory infiltration and myocardial necrosis, although it carries procedural risks and may yield false negatives.
Management is largely supportive, focusing on treatment of heart failure with medications such as diuretics, ACE inhibitors, and beta-blockers. Specific antimicrobial or antiviral therapy is used when an identifiable cause is present. In severe cases, advanced supportive measures such as ventricular assist devices or extracorporeal membrane oxygenation may be required, and cardiac transplantation may be considered in refractory cases. Adjunctive therapies such as intravenous immunoglobulin or immunosuppressive agents may be used selectively.
Follow-up care includes gradual rehabilitation, serial cardiac monitoring, and repeat imaging, with restrictions on physical activity during recovery. Long-term outcomes vary: some patients recover completely, while others develop complications such as dilated cardiomyopathy, arrhythmias, heart block, or cardiogenic shock. Early recognition and appropriate management are essential to improve prognosis and reduce the risk of serious complications, including sudden cardiac death.
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Infectious disease and microbiology – Myelitis
Myelitis is an inflammatory condition of the spinal cord caused by infection or involvement of adjacent tissues, leading to neurologic dysfunction affecting motor, sensory, and autonomic systems.
The epidemiology varies widely depending on the underlying infectious cause. It can occur in both immunocompetent and immunocompromised individuals, although the latter are at higher risk.
Risk Factors
Inflammation may involve:
Etiology
A wide range of infectious agents can cause myelitis:
Viral causes (most common):
History:
Transverse Myelitis:
Laboratory Tests:
Noninfectious causes include:
Targeted antimicrobial therapy based on cause:
Myelitis is an inflammatory condition of the spinal cord caused by infection or involvement of adjacent tissues, leading to neurologic dysfunction affecting motor, sensory, and autonomic systems.
The epidemiology varies widely depending on the underlying infectious cause. It can occur in both immunocompetent and immunocompromised individuals, although the latter are at higher risk.
Risk Factors
- Immunocompromised state (e.g., HIV, malignancy, steroid use)
- Vaccination against poliomyelitis and varicella-zoster virus (VZV)
Inflammation may involve:
- Entire cross-section of the spinal cord → transverse myelitis
- Focal segments → localized myelitis
- Nerve roots involvement → radiculomyelitis
Etiology
A wide range of infectious agents can cause myelitis:
Viral causes (most common):
- Herpes viruses (HSV, EBV, VZV, CMV, HHV-6)
- HIV (vacuolar myelopathy)
- HTLV-1 (tropical spastic paraparesis)
- Influenza virus
- Enteroviruses (coxsackie, echovirus, enterovirus 70/71)
- West Nile virus
- Mycoplasma pneumoniae
- Lyme disease (Borrelia burgdorferi)
- Syphilis (posterior column involvement – tabes dorsalis)
- Tuberculosis (spondylitis, tuberculomas)
- Leptospirosis
- Aspergillus, Coccidioides, Blastomyces
- Schistosomiasis
- Neurocysticercosis
- Epidural abscess causing spinal cord compression
History:
- Rapid onset (hours to days)
- Motor weakness (often bilateral)
- Sensory disturbances
- Bladder and bowel dysfunction
- Back pain or radicular (dermatomal) pain
Transverse Myelitis:
- Sensory level on the trunk
- Loss of motor and sensory function below lesion
- Reflexes initially decreased, later hyperactive
- Asymmetric weakness
- Fasciculations and muscle atrophy
- Loss of reflexes (lower motor neuron signs)
- Dermatomal pain and sensory loss
- Ipsilateral to rash
- Motor involvement is less common
Laboratory Tests:
- CSF analysis:
- Cell count, glucose, protein
- PCR for HSV, CMV, VZV
- West Nile virus IgM
- VDRL (for syphilis)
- Serology for HIV, Lyme disease, enteroviruses
- Normal glucose (viral causes)
- Elevated protein
- Lymphocytic predominance (except early herpes infections)
- MRI of the spine shows focal or diffuse enhancing lesions
- Inflammatory infiltration (lymphocytes, monocytes)
- Demyelination and axonal injury
Noninfectious causes include:
- Multiple sclerosis
- Vitamin B12 deficiency
- Autoimmune diseases (e.g., SLE)
- Neurosarcoidosis
- Paraneoplastic syndromes
Targeted antimicrobial therapy based on cause:
- HSV → Acyclovir
- CMV → Ganciclovir or foscarnet
- HIV → Antiretroviral therapy
- Other infections → Etiology-specific treatment
- Corticosteroids (e.g., IV methylprednisolone) are often used, though their benefit remains uncertain
- Emergency decompression if spinal cord compression (e.g., epidural abscess) is present
- Patients often require rehabilitation and neurologic follow-up
- Relapses may occur depending on etiology
- Chronic neuropathic pain
- Partial or complete paralysis
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Infectious disease and microbiology – Mycotic aneurysms
Mycotic aneurysms are infected aneurysms of blood vessels that arise as part of an infectious process, most commonly infective endocarditis (IE). Despite the name, “mycotic” refers to the fungus-like shape of the aneurysm, not the cause, which is usually bacterial.
These aneurysms may be intracranial or extracranial, and they can also occur due to infection of a preexisting aneurysm or arterial wall (microbial arteritis).
Epidemiologically, about 2–4% of patients with infective endocarditis develop intracranial mycotic aneurysms, although the true incidence is likely underestimated due to asymptomatic cases. The prevalence in the general population is unknown but has decreased in the antibiotic era.
Major risk factors include:
Clinically, many patients are asymptomatic until complications occur.
Symptoms depend on location:
Diagnosis relies on a combination of laboratory tests and imaging.
Treatment involves prolonged intravenous antibiotics (at least 6–8 weeks) tailored to the identified organism.
Some patients, especially those with intracranial aneurysms, may improve with antibiotics alone.
Surgical or endovascular intervention is required in cases of:
The prognosis is serious, with mortality depending on rupture status:
Mycotic aneurysms are infected aneurysms of blood vessels that arise as part of an infectious process, most commonly infective endocarditis (IE). Despite the name, “mycotic” refers to the fungus-like shape of the aneurysm, not the cause, which is usually bacterial.
These aneurysms may be intracranial or extracranial, and they can also occur due to infection of a preexisting aneurysm or arterial wall (microbial arteritis).
Epidemiologically, about 2–4% of patients with infective endocarditis develop intracranial mycotic aneurysms, although the true incidence is likely underestimated due to asymptomatic cases. The prevalence in the general population is unknown but has decreased in the antibiotic era.
Major risk factors include:
- Infective endocarditis
- Intravenous drug use
- Arterial trauma
- Contiguous infections near blood vessels
- Immunosuppression and advanced age
- Septic emboli from cardiac vegetations lodging in vessels
- Bacteremic seeding of damaged arterial intima
- Direct spread from nearby infections
- Direct inoculation from trauma or procedures
Clinically, many patients are asymptomatic until complications occur.
Symptoms depend on location:
- Intracranial aneurysms: headache, fever, stroke-like symptoms, seizures
- Aortic aneurysms: abdominal or back pain, fever
- Rupture: sudden deterioration, bleeding, shock
Diagnosis relies on a combination of laboratory tests and imaging.
- Blood cultures are positive in 50–85% of cases
- Elevated white blood cell count and anemia are common
- Conventional angiography is the gold standard
- CT, MRI, and Doppler ultrasound help localize and assess the aneurysm
Treatment involves prolonged intravenous antibiotics (at least 6–8 weeks) tailored to the identified organism.
Some patients, especially those with intracranial aneurysms, may improve with antibiotics alone.
Surgical or endovascular intervention is required in cases of:
- Rupture or bleeding
- Enlarging aneurysm despite therapy
- High-risk anatomical locations
The prognosis is serious, with mortality depending on rupture status:
- ~30% mortality if aneurysm is intact
- Up to 80% mortality if rupture occurs
- Hemorrhage (e.g., subarachnoid hemorrhage)
- Embolization
- Vascular insufficiency
- Shock and death
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Infectious disease and microbiology – Mumps
Mumps is a viral infection primarily affecting children, characterized by painful swelling of the parotid glands. Although usually mild and self-limited, it can lead to complications such as orchitis, pancreatitis, and aseptic meningitis, especially in adults.
The disease occurs worldwide and is caused by an enveloped RNA virus from the Paramyxoviridae family (genus Rubulavirus). Transmission occurs through direct contact with respiratory secretions of infected individuals.
Mumps most commonly affects children aged 5–9 years, although about one-third of cases occur in individuals older than 15 years. Widespread vaccination programs have significantly reduced incidence, particularly in developed countries. However, outbreaks can still occur, especially in crowded settings such as college campuses, even among vaccinated populations.
The incubation period ranges from 14 to 21 days, and up to 30–40% of infections may be asymptomatic. Symptomatic patients typically present with fever, malaise, headache, and painful swelling of the parotid glands, which develops within the first few days. Swelling is often bilateral and may be worsened by eating sour foods. Symptoms usually resolve within one week.
On physical examination, parotid enlargement leads to obliteration of the mandibular angle and upward displacement of the ear. Other salivary glands may occasionally be involved.
Complications can occur, particularly in post-pubertal individuals.
Orchitis affects up to 30% of post-pubertal males, presenting with testicular pain, swelling, and fever.
In females, oophoritis and mastitis may occur.
Aseptic meningitis is relatively common but typically self-limited.
Other complications include transient hearing loss, pancreatitis, and rarely encephalitis.
Diagnosis is usually clinical, based on characteristic features. Laboratory findings may include leukopenia and elevated serum amylase.
Confirmation can be achieved with serologic testing (IgM/IgG ELISA) or PCR detection of viral RNA from saliva, cerebrospinal fluid, or urine.
There is no specific antiviral treatment for mumps. Management is supportive and includes rest, hydration, and analgesics.
In cases of orchitis, additional measures such as scrotal elevation, cold compresses, and NSAIDs are recommended.
Prevention relies on vaccination, typically given as part of the MMR (measles–mumps–rubella) vaccine, administered in childhood with two doses. Isolation of infected individuals for 5 days after onset of parotitis helps limit transmission.
The prognosis is generally excellent, with lifelong immunity after infection.
Complications are uncommon but may include testicular atrophy, reduced sperm counts, hearing loss, encephalitis, and, rarely, permanent neurologic damage.
In pregnancy, mumps infection has been associated with fetal complications, including low birth weight and fetal loss.
Mumps is a viral infection primarily affecting children, characterized by painful swelling of the parotid glands. Although usually mild and self-limited, it can lead to complications such as orchitis, pancreatitis, and aseptic meningitis, especially in adults.
The disease occurs worldwide and is caused by an enveloped RNA virus from the Paramyxoviridae family (genus Rubulavirus). Transmission occurs through direct contact with respiratory secretions of infected individuals.
Mumps most commonly affects children aged 5–9 years, although about one-third of cases occur in individuals older than 15 years. Widespread vaccination programs have significantly reduced incidence, particularly in developed countries. However, outbreaks can still occur, especially in crowded settings such as college campuses, even among vaccinated populations.
The incubation period ranges from 14 to 21 days, and up to 30–40% of infections may be asymptomatic. Symptomatic patients typically present with fever, malaise, headache, and painful swelling of the parotid glands, which develops within the first few days. Swelling is often bilateral and may be worsened by eating sour foods. Symptoms usually resolve within one week.
On physical examination, parotid enlargement leads to obliteration of the mandibular angle and upward displacement of the ear. Other salivary glands may occasionally be involved.
Complications can occur, particularly in post-pubertal individuals.
Orchitis affects up to 30% of post-pubertal males, presenting with testicular pain, swelling, and fever.
In females, oophoritis and mastitis may occur.
Aseptic meningitis is relatively common but typically self-limited.
Other complications include transient hearing loss, pancreatitis, and rarely encephalitis.
Diagnosis is usually clinical, based on characteristic features. Laboratory findings may include leukopenia and elevated serum amylase.
Confirmation can be achieved with serologic testing (IgM/IgG ELISA) or PCR detection of viral RNA from saliva, cerebrospinal fluid, or urine.
There is no specific antiviral treatment for mumps. Management is supportive and includes rest, hydration, and analgesics.
In cases of orchitis, additional measures such as scrotal elevation, cold compresses, and NSAIDs are recommended.
Prevention relies on vaccination, typically given as part of the MMR (measles–mumps–rubella) vaccine, administered in childhood with two doses. Isolation of infected individuals for 5 days after onset of parotitis helps limit transmission.
The prognosis is generally excellent, with lifelong immunity after infection.
Complications are uncommon but may include testicular atrophy, reduced sperm counts, hearing loss, encephalitis, and, rarely, permanent neurologic damage.
In pregnancy, mumps infection has been associated with fetal complications, including low birth weight and fetal loss.
