Perianal streptococcal dermatitis (PSD) is a pediatric dermatologic infectious disease predominantly affecting children, particularly younger children, which is most commonly caused by group A beta-hemolytic streptococci (GABHS). Although the clinical picture of a sharply demarcated erythema is very characteristic, PSD is often misdiagnosed for long periods of time and patients are subjected to treatments for a variety of differential diagnoses. Vulvar and penile involvement with similar signs and symptoms have been documented in several patients with PSD. The diagnosis is made by either a swab of the affected region submitted for microbiological analysis with the specific question for GABHS, or a rapid strep test. Systemic antibiotics such as penicillin, erythromycin, newer macrolides, or others, probably augmented by topical antiseptic or antibiotic ointments are the treatment of choice. Treatment duration should be at least 14 days or, even better, 21 days, and be dictated by clinical and microbiological cure. Therefore treatment success should be investigated not only by clinical examination but also by post-treatment perineal swabs as well as a urine analysis to monitor for post-streptococcal glomerulonephritis. The author of this review supports the recent suggestion to summarize GABHS-induced vulvovaginal and penile infections together with PSD under the inclusive term 'perineal streptococcal disease' because these conditions coincide, share important clinical characteristics and, therefore, represent manifestations of the same disease.