Guttate psoriasis triggered by perianal streptococcal dermatitis in a four-year-old boy

Perianal streptococcal dermatitis (PSD) is a superficial bacterial infectio n usually with group A betahemolytic streptococci, PSD is often misdiagnose d for long periods and patients are subjected to treatments for a variety o f differential diagnoses without success. We report a 4-year-old boy with P SD who presented to our clinic with guttate psoriasis for 2 reasons: first, to make dermatologists aware of PSD and second, to emphasize the necessity to examine patients, particularly pediatric patients, with guttate psorias is very thoroughly and swab both the pharynx and perianal and/or perigenita l areas even when they are, or seem to be, asymptomatic for bacterial infec tions. Once PSD has been diagnosed, systemic antibiotic therapy with penici llin, erythromycin., roxithromycin, or azithromycin (probably augmented by topical mupirocin ointment) should be the treatment of choice. Therapy shou ld be monitored by posttreatment perianal and throat swabs as well as a uri ne analysis to monitor for poststreptococcal glomerulonephritis.