- Published on
Emergency and Acute Medicine – Lymphangitis
Basics description
Lymphangitis is an infection of the lymphatic vessels that drain an area of inflammation or infection. Histologically, lymphatic channels become dilated and filled with lymphocytes and histiocytes. Inflammation often extends into surrounding perilymphatic tissues and may progress to cellulitis or abscess formation if untreated.
Etiology
Acute lymphangitis is most commonly caused by bacterial infection, particularly group A β-hemolytic Streptococcus. Less common causes include other streptococcal species and Staphylococcus aureus, including community-associated methicillin-resistant S. aureus (CA-MRSA). CA-MRSA risk factors include prior MRSA infection, close household contact, military service, incarceration, contact sports, injection drug use, and men who have sex with men. CA-MRSA is now prevalent enough to warrant empiric coverage in many settings, especially in unresponsive or recurrent infections. Other causes include Pasteurella multocida from animal bites, Spirillum minus in rat-bite fever, and Wuchereria bancrofti in filariasis, particularly in immigrants from endemic regions. Chronic lymphangitis is usually due to fungal, mycobacterial, or parasitic infections, most commonly Sporothrix schenckii, acquired through gardening or farming injuries, and Mycobacterium marinum, associated with fish tanks and swimming pools.
Diagnosis signs and symptoms
Acute lymphangitis presents with warm, tender, erythematous streaks extending proximally from a primary site of infection toward regional lymph nodes. Associated findings include painful lymphadenopathy, peripheral edema of the involved extremity, and systemic symptoms such as fever, rigors, tachycardia, and headache. Chronic nodular lymphangitis typically presents with painless erythematous nodules, chancriform ulcers, or wart-like lesions at the inoculation site, with possible progression along lymphatic channels and minimal systemic symptoms.
Essential workup
Lymphangitis is primarily a clinical diagnosis based on history and physical examination, with attention directed toward identifying the source of infection.
Diagnosis tests and interpretation
Laboratory testing is often unnecessary, though leukocytosis may be present. Gram stain and culture of aspirate or biopsy from the most inflamed area are recommended in cases of treatment failure or when resistant organisms such as MRSA are suspected. Culture confirmation is essential when sporotrichosis or M. marinum infection is considered. Blood cultures may be positive in severe cases. Imaging is rarely required but plain radiographs may help identify abscesses, subcutaneous gas, or foreign bodies, and Doppler ultrasound may be useful to exclude deep venous thrombosis.
Differential diagnosis
The differential diagnosis includes superficial or deep thrombophlebitis, which typically lacks an initial infectious focus or regional lymphadenopathy, IV line infiltration, vaccine-related reactions, and phytophotodermatitis, which can cause linear inflammatory skin changes mimicking lymphangitis.
Treatment
Initial management focuses on stabilizing septic patients with airway support and resuscitation as needed. Antimicrobial therapy should be initiated promptly, with the first dose given in the emergency department. Treatment typically lasts 7–10 days and includes limb elevation, moist heat, and antibiotics guided by local resistance patterns. Empiric outpatient therapy often includes oral cephalexin plus trimethoprim–sulfamethoxazole to cover CA-MRSA, with alternatives such as clindamycin or doxycycline. Inpatient therapy may require IV nafcillin or equivalent agents. Animal bite–associated lymphangitis is treated with IV ampicillin–sulbactam. Chronic infections require organism-specific therapy, such as itraconazole or potassium iodide for sporotrichosis and combination antimycobacterial therapy for M. marinum.
Disposition and follow-up
Admission is indicated for toxic-appearing patients, those with immunosuppression, significant comorbidities, inability to tolerate oral therapy, or unreliable follow-up. Patients with mild disease who are clinically stable and able to take oral antibiotics may be discharged with close follow-up within 24–48 hours. Marking the borders of erythema before discharge helps assess treatment response.
Pearls and pitfalls
Empiric antibiotic therapy should include coverage for CA-MRSA in addition to streptococcal species. Failure to recognize resistant organisms or chronic infectious causes can lead to treatment failure and progression of disease.
Basics description
Lymphangitis is an infection of the lymphatic vessels that drain an area of inflammation or infection. Histologically, lymphatic channels become dilated and filled with lymphocytes and histiocytes. Inflammation often extends into surrounding perilymphatic tissues and may progress to cellulitis or abscess formation if untreated.
Etiology
Acute lymphangitis is most commonly caused by bacterial infection, particularly group A β-hemolytic Streptococcus. Less common causes include other streptococcal species and Staphylococcus aureus, including community-associated methicillin-resistant S. aureus (CA-MRSA). CA-MRSA risk factors include prior MRSA infection, close household contact, military service, incarceration, contact sports, injection drug use, and men who have sex with men. CA-MRSA is now prevalent enough to warrant empiric coverage in many settings, especially in unresponsive or recurrent infections. Other causes include Pasteurella multocida from animal bites, Spirillum minus in rat-bite fever, and Wuchereria bancrofti in filariasis, particularly in immigrants from endemic regions. Chronic lymphangitis is usually due to fungal, mycobacterial, or parasitic infections, most commonly Sporothrix schenckii, acquired through gardening or farming injuries, and Mycobacterium marinum, associated with fish tanks and swimming pools.
Diagnosis signs and symptoms
Acute lymphangitis presents with warm, tender, erythematous streaks extending proximally from a primary site of infection toward regional lymph nodes. Associated findings include painful lymphadenopathy, peripheral edema of the involved extremity, and systemic symptoms such as fever, rigors, tachycardia, and headache. Chronic nodular lymphangitis typically presents with painless erythematous nodules, chancriform ulcers, or wart-like lesions at the inoculation site, with possible progression along lymphatic channels and minimal systemic symptoms.
Essential workup
Lymphangitis is primarily a clinical diagnosis based on history and physical examination, with attention directed toward identifying the source of infection.
Diagnosis tests and interpretation
Laboratory testing is often unnecessary, though leukocytosis may be present. Gram stain and culture of aspirate or biopsy from the most inflamed area are recommended in cases of treatment failure or when resistant organisms such as MRSA are suspected. Culture confirmation is essential when sporotrichosis or M. marinum infection is considered. Blood cultures may be positive in severe cases. Imaging is rarely required but plain radiographs may help identify abscesses, subcutaneous gas, or foreign bodies, and Doppler ultrasound may be useful to exclude deep venous thrombosis.
Differential diagnosis
The differential diagnosis includes superficial or deep thrombophlebitis, which typically lacks an initial infectious focus or regional lymphadenopathy, IV line infiltration, vaccine-related reactions, and phytophotodermatitis, which can cause linear inflammatory skin changes mimicking lymphangitis.
Treatment
Initial management focuses on stabilizing septic patients with airway support and resuscitation as needed. Antimicrobial therapy should be initiated promptly, with the first dose given in the emergency department. Treatment typically lasts 7–10 days and includes limb elevation, moist heat, and antibiotics guided by local resistance patterns. Empiric outpatient therapy often includes oral cephalexin plus trimethoprim–sulfamethoxazole to cover CA-MRSA, with alternatives such as clindamycin or doxycycline. Inpatient therapy may require IV nafcillin or equivalent agents. Animal bite–associated lymphangitis is treated with IV ampicillin–sulbactam. Chronic infections require organism-specific therapy, such as itraconazole or potassium iodide for sporotrichosis and combination antimycobacterial therapy for M. marinum.
Disposition and follow-up
Admission is indicated for toxic-appearing patients, those with immunosuppression, significant comorbidities, inability to tolerate oral therapy, or unreliable follow-up. Patients with mild disease who are clinically stable and able to take oral antibiotics may be discharged with close follow-up within 24–48 hours. Marking the borders of erythema before discharge helps assess treatment response.
Pearls and pitfalls
Empiric antibiotic therapy should include coverage for CA-MRSA in addition to streptococcal species. Failure to recognize resistant organisms or chronic infectious causes can lead to treatment failure and progression of disease.
0 Comments
