[Isolation of group A beta-hemolytic Streptococcus in children with perianal dermatitis]

Perianal dermatitis due to group A beta-hemolytic streptococcus is a rare diagnosis in pediatrics. Clinical manifestations include erythema, edema, and perianal pruritus associated with vulvovaginitis or balanitis, painful defecation, constipation, anal fissures, purulent discharge, and/or rectal bleeding.

A descriptive, observational, prospective study was conducted between May, 2004 and April, 2005. In children presenting to the emergency room with erythema, edema, and perianal pruritus, a rapid streptococcal antigen test and bacterial cultures of their perianal secretions were obtained. Patients with a positive result in the rapid test were treated with oral phenoxymethylpenicillin (40-50 mg/kg/day) for 10 days, after which clinical and bacteriological evaluations were conducted.

Of the 24 patients presenting with erythema, edema, and perianal pruritus, 19 patients (12 boys and 7 girls), aged between 6 months and 4 years (median age: 30 months), tested positive for group A beta-hemolytic streptococcus. Nine patients also presented with constipation, 5 with anal fissures, 4 with rectal bleeding, 2 with vulvovaginitis, and 1 with streptococcal pharyngoamygdalitis. Outcome was favorable in 85 % of the patients, and perianal isolation of group A beta-hemolytic streptococcus was negative after treatment in 95 %.

In patients presenting with erythema, edema, and perianal pruritus, perianal streptococcal dermatitis should be ruled out. The rapid test for streptococcal antigen detection is a quick and reliable method for this diagnosis. The antibiotic of choice is oral penicillin.