Article: Mycoplasma pneumonia

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2893430

• M. pneumoniae can affect the upper or lower respiratory tracts or both. 
• Symptoms commonly appear gradually, during a few days, and can persist for weeks or months. 
• Typical clinical features include an initial pharyngitis, sore throat and hoarseness, fever, cough
• Initially cough is non-productive but later may yield small to moderate amounts of non-bloody sputum. 
• Dyspnea may be evident in more severe cases. 
• Children under five years of age are most likely to manifest coryza and wheezing, and progression to pneumonia is relatively uncommon, whereas older children are more likely to develop bronchopneumonia in one or more lobes, even sometimes requiring hospitalizations. 
• Central nervous system (CNS) manifestations are the most frequent extra-pulmonary complications of M. pneumoniae infection and can at times be life threatening. Encephalitis and meningoencephalitis are most common. 
• Skin manifestations: Stevens-Johnson syndrome, Toxic epidermal necrolysis, erythema multiforme (target lesions, but without mucosal involvement and systemic toxicity) and pityriasis rosea. 
• GI : nausea, vomiting, abdominal pain, diarrhea and loss of appetite. Cholestatic hepatitis and pancreatitis, albeit rare, can occur.
• Musculoskeletal: Polyarthritis of mycoplasma origin could mimic acute rheumatic fever. Unlike in rheumatic fever, polyarthritis of mycoplasma origin is usually associated with a moderately high ESR and there is no neutrophil leucocytosis.

• Effect on asthma: M. pneumoniae, primarily considered a causative agent of CAP has recently been linked to asthma in various ways. Infection with this organism may precede the onset of asthma. Secondly, it may exacerbate asthma and make control of asthma more difficult. 
• Xray: diffuse, reticular infiltrates of bronchopneumonia in the perihilar regions or lower lobes, usually with a unilateral distribution, and hilar adenopathy.
• Enzyme immunoassays (EIAs) are the most widely used and reliable commercial Mycoplasma serology tests. It allows IgG and IgM titration and presents 92% sensitivity and 95% specificity on paired samples.