Citrobacter koseri folliculitis of the face.

We report a case of severe Citrobacter koseri folliculitis of the face in a boy with acne. A 15-year-old boy affected by acne was admitted because of a rash located on the face. Dermatological examination revealed two large plaques, with numerous pustules, eschars and crusts, located bilaterally and symmetrically on the cheeks. Three bacteriological examinations were positive for C. koseri. The patient was successfully treated with i.m. ceftriaxone. C. koseri is a Gram-negative, aerobic, mobile, nonsporulating bacillus belonging to the Enterobacteriaceae family. It can cause meningitis, central nervous system abscess and sepsis, almost exclusively in infants and immunocompromised hosts. Respiratory tract and urinary infections have been reported in elderly people. Furthermore, rare cases of skin infections have been described.