Community Acquired Atypical Pneumonia.

Atypical implies moderate amounts of sputum, absence of physical findings of consolidation, only moderate elevation of white cell count, and lack of alveolar exudates

Pt presents with nonspecific febrile illness characterized by fever, headache, and malaise and, later, cough with minimal sputum

Mycoplasma pneumoniae, influenza types A and B, the respiratory syncytial viruses, adenovirus, rhinoviruses, rubeola, varicella , Chlamydia pneumoniae, Ricketsia and Coxiella burnetti , coronavirus causing Severe Acute Respiratory Syndrome (SARS),

denudation of the respiratory epithelium inhibits mucociliary clearance and predisposes to secondary bacterial infections

process may be patchy

inflammatory reaction is largely confined within the walls of the alveoli with lymphocytes, histiocytes, and, occasionally, plasma cells

alveolar spaces in atypical pneumonias are remarkably free of cellular exudate

Due to the alveolocapillary block, there may be respiratory distress seemingly out of proportion to the physical and radiographic findings

PCR testing for Mycoplasma available

macrolide antibiotic.