Perianal streptococcal dermatitis in adults.

Perianal streptococcal dermatitis is an uncommon superficial cutaneous infection of the perianal area almost exclusively described in children. We report here four adult cases. Beta-haemolytic streptococcus group A was detected in the perianal areas of all the patients. Systemic erythromycin gave complete resolution. The incidence of perianal streptococcal dermatitis in adults is probably underestimated, and culture from the affected area should always be performed in patients with persistent perianal erythema.