​Kembara Xtra - Medicine - Mycoplasma Pneumonia

​Kembara Xtra - Medicine - Mycoplasma Pneumonia 
Mycoplasma pneumoniae, a type of Mycoplasma, is responsible for bronchopulmonary infection. Most frequently affects children and young adults, but can also affect the elderly. Frequently causes epidemics in closed communities (such as skilled nursing facilities). Smallest free-living organism; fastidious and slow-growing; first isolated in cattle in 1898. Infection may be asymptomatic, most commonly confined to the upper respiratory tract, but may progress to pneumonia (5-10%).  The incubation time is usually 1 to 4 weeks, and the course is typically acute.
Alternative names for walking pneumonia include cold agglutinin-positive pneumonia, Eaton agent pneumonia, and primary atypical pneumonia (PAP). 

Aspects of Geriatrics

Seniors have the highest rate of ICU admissions for M. pneumoniae-related community-acquired pneumonia (CAP).

Child Safety Considerations

 Has a substantial impact on pneumonias in kids of all ages (viral infection is much more typical in pneumonia in children under 5 years old).
Infants between the ages of three and six months who have suspected bacterial pneumonia should be admitted to the hospital.

Epidemiology Incidence Estimated 1 million cases each year in the United States 20% of CAP needing hospitalizations per year Infection most usually occurs in the fall and winter seasons, though it can occur at any time of year.
Prevalence
Males are more likely than females to be affected. The most common age group affected is 5 to 20 years, although it can happen at any age. Up to 15-20% of CAP cases each year are caused by this, making it the most common cause of pneumonia in school-age children and young adults without a chronic underlying condition. 

Pathophysiology and Etiology 
M. pneumoniae is a short-rod mucosal pathogen that can grow in both aerobic and anaerobic environments. It lacks a cell wall, making it invisible on a Gram stain. M. pneumoniae is very contagious and spreads mainly by aerosol droplets. Its filamentous tips are pathogenic because they selectively bind to respiratory epithelial cell membrane proteins, producing H2O2 and superoxide radicals that harm cilia. Decreased ciliary movement results in a protracted paroxysmal, hacking cough, and the incubation period is 2 to 3 weeks. Many pathogenic characteristics of infection are thought to be immunological mediated, rather than directly generated.
M. pneumoniae infection may worsen asthma symptoms as well as cause wheezing in children without asthma. M. pneumoniae infection may worsen chronic obstructive pulmonary disease (COPD) or other chronic pulmonary conditions symptoms in adults. ALERT Infection by M. pneumoniae has become recognized as a worldwide cause of CAP.
RISK FACTORS Smoking Close community living (e.g., military barracks, prisons, hospitals, dormitories, schools, home contacts, skilled care facilities) Immunocompromised status (e.g., HIV, transplant recipients, chemotherapy)  

Prevention 

Think about isolating droplets from active cases.


Chronic obstructive pulmonary disease and asthma exacerbations brought on by the production of proinflammatory cytokines

The infection may not show any symptoms.
 Gradual onset of chills, low-grade fevers, malaise, and headache  Upper respiratory infection symptoms, such as persistent nonproductive cough, increasing cough (which may turn minimally productive later in the illness), and pleurisy; rhinorrhea, pharyngitis, and sinusitis may also follow.
A pleural effusion and pneumonia may coexist.
Pleuritic chest pain raises the likelihood that M. pneumoniae is the cause.
Extrapulmonary signs, such as arthralgias, skin rashes, cervical adenopathy, hemolysis, congestive heart failure (CHF), and aberrant cardiac conduction, may manifest in 5–10% of patients.
Children are more likely to experience neurologic symptoms, which might include encephalitis, aseptic meningitis, cranial nerve palsies, cerebellar ataxia, ascending paralysis, and coma. During recovery, persistent cough is typical; additional sequelae are uncommon.

clinical assessment 
With growing age or a greater number of comorbidity factors, toxicity increases.
Fever and lassitude may also be present, as well as a hacking or pertussis-like cough.
Early infection results in normal lung findings, but rhonchi, rales, and/or wheezes may appear several days later.
 Mild injection of the pharynx without exudates No or less cervical adenopathy
A rare but distinctive sign is erythematous tympanic membranes or bullous myringitis in patients older than 2 years old.
Some patients may experience audible pleural friction rub. a number of exanthems, including Stevens-Johnson syndrome and erythema multiforme. 

Differential diagnosis includes: viral, bacterial, and fungal pneumonia; tuberculosis; other atypical pneumonias, such as Chlamydia pneumoniae, Chlamydophila psittaci, Coxiella burnetii (Q fever), Francisella tularensis (tularemia), Pneumocystis jiroveci, Legionella pneumophila, and other community-acquired pneumonias; 

Laboratory Results 
M. pneumoniae is normally diagnosed clinically and treated empirically; however, polymerase chain reaction (PCR) testing is the preferred method when specific pathogen testing is required.
There is no way to tell M. pneumoniae apart from other atypical pneumonia pathogens (Chlamydia/Legionella) based on clinical or radiographic characteristics.
Initial examinations (lab, imaging)
WBC count could be low or high.
Although it has been described, hemolytic anemia is uncommon.
Elevated erythrocyte sedimentation rate (ESR), however nonspecific, may be present.
The rise in levels is typically more mild for atypical etiologies and may be undetectable for Mycoplasma species, which limits the use of procalcitonin levels.
 When available, PCR for M. pneumoniae DNA in tissue samples, bronchoalveolar lavage respiratory secretions, CSF, and nasopharyngeal and throat swabs, may be the most sensitive and specific test.
Although this is not specific, CXR displays reticulonodular pattern with patchy patches of lower lobe consolidation.
In 10% to 15% of instances, a little pleural effusion may be detected.

Tests in the Future & Special Considerations

Gram stains performed on sputum are useless because M. pneumoniae has no cell wall and cannot be stained.
M. pneumoniae is challenging to culture and needs 7 to 21 days to grow; culturing is successful in 40–90% of cases but does not offer information to direct treatment, therefore it is rarely done.
An older method known as the complement fixation serologic assay reveals a 4-fold increase in IgM antibody titer 2 to 4 weeks after the onset of symptoms.
 Positive cold agglutinins (titer of 1:128 or growing 4-fold) in 50% of infections; however, it might take 1–2 weeks for them to develop and they are neither sensitive nor specific, thus they are not usually advised. A patchy tree-in-bud opacity and segmental ground-glass opacity may be visible on a chest CT.

Management 
Avoid contact with sick people. Supportive care is recommended, especially for seriously unwell patients who may need to be admitted. Initial therapy is empirical and must be thorough to address all possible pathogens in the context of the clinical scenario.
Determine if inpatient or outpatient care is best by using the pneumonia severity score calculator (CAP score: http://www.mdcalc.com/psi-port-score-pneumoniaseverity-index-adult-cap).

Caution 
The effectiveness of antibiotics in treating pediatric M. pneumoniae-infected kids younger than 24 months old is not supported by enough research. However, other studies support the use of amoxicillin with a macrolide to treat CAP in order to cover M. pneumoniae as well as other possible causative agents.
pregnant women's issues
Clarithromycin, levofloxacin, and moxifloxacin are pregnancy Category C medications while azithromycin is pregnancy Category B (recommended treatment).


First Line of Medicine
Azithromycin: under 3 months: not established; above 3 months: day 1, 10 mg/kg PO 1 (not to exceed 500 mg); days 2 to 5, 5 mg/kg PO daily (not to exceed 250 mg/day); - For adults, use 500 mg PO on day 1 and then 250 mg PO daily for 4 days.
Doxycycline is not advised for use in children under the age of eight.
- Children >8 years old (45 kg): 200 mg/day PO split BID for 10–14 days; 2–4 mg/kg/day up to that amount; - Children over 8 years old (under 45 kg): Use adult dosage.
- 100 mg PO BID for adults for 7 to 14 days.
- Effective against macrolide-resistant M. pneumoniae strains - Children under 6 months of age: not established
- Patients older than 6 months: 15 mg/kg/day administered orally, split every 12 hours for 10 to 14 days. - For adults, take 250–500 mg PO BID for 10–14 days.
Minocycline: 200 mg PO/IV, given as a single dose, followed by 100 mg BID every day for seven to ten days. Erythromycin: children: 20 to 50 mg/kg/day (base). 10 to 14 days, split by q6-8 hours. - Adults: 500 mg (base) PO every six hours for 10 to 14 days.

Next Line
Levofloxacin is not advised for use in children under the age of 18 and should be administered to adults only in doses of 750 mg daily for five days. Moxifloxacin is also not advised for use in children under the age of 18 and should be administered to adults only in doses of 400 mg daily for seven to ten days. Consider using it in conjunction with other pneumonia infections and concomitant illnesses; it's particularly helpful if macrolide resistance is detected. 

Further Treatments 

 Albuterol inhaler: 2 puffs every 4 to 6 hours as necessary for wheezing
Dexamethasone may inhibit the secretion of cytokines.
 Additional oxygen if required Acetaminophen/ibuprofen as needed for fever
Up to 10.9% of patients in hospitals can need mechanical ventilation.
In cases of severe hemolytic anemia, plasmapheresis is used.

Admission 
Other grading systems, such as the CURB65 and Pneumonia Severity Index (PSI), may also be useful in deciding whether to receive treatment in a hospital or outpatient setting.
 Comorbid conditions and advanced age Complicating neoplastic illness
Tachycardia/tachypnea, Hypotension, Neurologic Symptoms, Significant Cerebrovascular, Cardiac, Renal, Liver, or GI Symptoms, Changed Mental Status, Inability to Maintain Oxygen Saturation,
Significant hemolysis (autoimmune hemolytic anemia, cold agglutinin illness), Stevens-Johnson syndrome symptoms When the following conditions are met: - Respiratory distress and hypoxia have subsided.
- Oral hydration is being tolerated by patients.
- There aren't any major issues at the moment.
Procalcitonin (PCT) use may help with this decision.
 Before discharge, there is typically no requirement for a 24-hour observation period while taking oral antibiotics.

Follow-Up Patients over 50 years of age should have the clearing of their ailment on a CXR documented.
Document a clean CXR in 6 to 8 weeks in smokers.
 Patients should seek medical assistance right away if their symptoms get worse, a rash appears, or they exhibit meningeal or neurological symptoms.
It is not usually advised to give exposed contacts antibiotic prophylaxis.
Macrolide or doxycycline prophylaxis should be given for household contacts who may be susceptible to severe mycoplasmal infection.
No special dietary precautions are needed.
 Be sure to drink enough water.

Lifestyle changes, quitting smoking, contact and droplet protection, and effective hand washing methods

Prognosis: problems often go away after two weeks, while some constitutional problems may last longer. With the right treatment, even the most severe cases can expect a full recovery.

Except for reactive airway disease, hemolytic anemia, and erythema multiforme, all effects are uncommon.
Patients with sickle cell anemia who have reactive airway disease may experience chronic chest pain.
Meningoencephalitis, aseptic meningitis, peripheral neuropathy, transverse myelitis, acute transverse myelitis, cerebellar ataxia, acute disseminated encephalomyelitis, Guillain-Barré syndrome, polyarthritis, Stevens-Johnson syndrome, pericarditis, myocarditis, respiratory distress syndrome, cerebellar ataxia, thromboembolic phenomena, pleural effusion, ne

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