Mycoplasma pneumonia

Often causes mild illness with upper resp symptoms
Etiology no peptidoglycan cell wall
Epidemiology "every 4 years"; often affects younger patients
Symptoms: Upper resp symptoms before lower resp. Dry cough. Gradual onset.
Signs: Mucocutaneous: erythema multiforme, erythema nodosum
Haem: haemolytic anaemia (due to cold haemagglutinins) → positive DAT, negative IgG
GI: gastroenteritis, hepatitis, acute pancreatitis
CNS: meningoencephalitis, ADEM, GBS, cranial nerve palsies - likely immune-mediated
Investigations: CXR usually looks worse than clinical findings
Sputum: Mycoplasma has no cell wall so no appearance on Gram stain
CRP/PCT ratio raised???
Management: Macrolides or fluoroquinolones