- Hemophilus influenzae f was responsible for cellulitis with bacteremia, pleuritis, and peritonitis in an adult patient with the nephrotic syndrome. The patient rapidly responded to ampicillin. H influenzae f has previously been rarely found to cause pleuritis and bacteremia, but has not been reported as a cause of cellulitis or primary peritonitis. Patients with the nephrotic syndrome are prone to serious infection with encapsulated bacteria. The relative frequency of infection with the various encapsulated bacteria most likely parallels that of colonization by these organisms.