The presence of intense perianal erythema with or without scale caused by infection with group A beta-hemolytic Streptococci. Group B Streptococci and non-group A or group B Streptococci have been reported in some cases. It typically occurs between the ages of 6 months and 10 years. It has been rarely reported in adults. It can occur in children with streptococcal pharyngitis, but gastric acid should eliminate most of the swallowed pharyngeal bacteria. Digital contamination from an infected site (eg, as pharynx or skin) may be the source. Intrafamilial spread is thought to be due to communal bathing or direct contamination. Diapering by a caregiver with streptococcal pharyngitis or carriage may also cause transfer of the infective organism.