Findings: Single PA view of the chest demonstrates patchy, primarily perihilar interstitial infiltrates consistent with viral pneumonia.

Diagnosis: Varicella pneumonia.

Discussion: Pneumonias due to viral etiologies in general demonstrate interstitial infiltrates, in contrast to the usual pulmonary consolidation caused by bacterial pathogens. Chicken pox is the primary disease that results from infection with varicella-zoster virus. A presumptive diagnosis of varicella pneumonia can be made when there is co-existing chicken pox and pneumonia. Although rare in children, pneumonia complicates approximately 30% of immunocompetent adults with chicken pox. Varicella pneumonia generally presents with dyspnea, cough, and tachypnea, as well as fever. Pregnant women are particularly prone to develop severe (often life threatening) disease.

The chest radiograph in early varicella pneumonia demonstrates peribronchial thickening. Later, the more characteristic pattern of diffuse, patchy, interstitial infiltrates and airspace consolidation develops, often producing multiple acinar nodules. The pneumonia and skin rash generally clear simultaneously, but the acinar nodules may remain for weeks to months. Calcifications similar to these seen with histoplasmosis are a not uncommon sequella.