All of the following features are seen in the viral pneumonia except :
Answer is B (Predominance of alveolar exudates) Viral pneumonias are an example of 'atypical pneumonias' and are characterized by inflammatory reaction predominantly restricted within the walls of alveoli within the inteitium. The alveoli may be free from exudates - Robbins. The alveolar septa are widened and edematous and usually have a mononuclear inflammatory infiltrate. Alveoli may be free from exudates but in many patients there is accumulation of intraalveolar proteinaceous matriale, a cellular exudates and characteristically pink hyaline membranes. These changes reflect alveolar damage similar to that seen diffusely in ARDS. AIR Space Penumonia (Typical Pneumonia) Interstitial Pneumonia (Atypical Pneumonia) Exudate in alveoli i.e. consolidation No exudate, alveoli are air filled i.e. no consolidation (infiltrate in interstitium) Infiltrate is primarily of neutrophills (PMN) Infiltrate is primarily lymphatic Agents responsible are extracellular Agents responsible are intracellular Cough is productive of purulent sputum Cough is dry Chest X-ray shows alveolar pattern Chest X-ray shows interstitial pattern
Presence of interstitial inflammation
Predominance of alveolar exudates.
Bronchiolitis.
Multinucleate giant cells in the bronchiolar wall