Background: Pediatric perianal streptococcal dermatitis (PSD) is a well-defined clinical entity. However, its highly uniform presentation remains surprisingly unrecognized by many practitioners 33 years after its first description.
Case report: A seven-year-old girl had a three-week history of perianal and vulva redness with well-defined margins. Functional symptoms associated perirectal tenderness and pain during defecation, which was responsible for constipation. At onset she also presented with a sore throat, which resolved spontaneously, and she had been complaining for a few days about a perioral impetigo. She received mycostatin unsuccessfully for an alleged candidiasis. Positive cultures for group A beta-hemolytic streptococci from both perirectal and perioral swabs confirmed the diagnosis of PSD. Therapy with amoxicillin (50 mg/kg/d) was prescribed for ten days. Perianal lesions were cleared by day 2.
Conclusion: Since PSD can masquerade as candidiasis, psoriasis, seborrheic dermatitis, inflammatory bowel disease or even sexual abuse, it remains an underdiagnosed entity. This situation leads to delayed diagnosis and treatment which in turn might increase the frequency of secondary complications related to streptococcal infections (i.e., post-streptococcal acute nephritis and rheumatism, guttate psoriasis, etc.).