A link between perianal strep and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS).

Perianal streptococcal dermatitis is an infection caused by group A streptococcus (GAS). Children with a pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS) phenotype may have tics or obsessive compulsive symptoms secondary to a systemic immune activation by GAS infecting perianal areas. In this retrospective case series, the authors describe three children with symptoms consistent with PANDAS and a confirmed perianal streptococcal dermatitis as the likely infectious trigger. Concomitant perianal dermatitis and new-onset obsessive-compulsive symptoms and/or tics are strong indications for perianal culture and rapid antigen detection test in young children.