Herpes simplex viral pneumonitis in childhood

We report two cases of herpes simplex pneumonia in children. One patient had Down syndrome, and the other was immunosuppressed by cancer therapy. Both had interstitial pneumonitis with nonspecific physical, radiographic, and laboratory findings, and both died. The diagnosis of herpes simplex pneumonia was made by isolation of herpes simplex virus from autopsy lung cultures as well as by demonstration of antigen in the tissue with an immunoperoxidase procedure. Inasmuch as herpes simplex pneumonia is a potentially treatable infection, early virologic studies are recommended in immunocompromised children with progressive pneumonitis of undetermined cause.