Group A Streptococcus has been associated with a perianal infection. We conducted a systematic review of the literature on childhood streptococcal perianitis in three databases: Excerpta Medica, National Library of Medicine, and Web of Science. The main purposes were to document the clinical features, the tendency to recur, the association with an asymptomatic streptococcal throat carriage, the accuracy of rapid streptococcal tests, and the mechanism possibly underlying the acquisition of this infection. More than 80% of cases are boys ≤7.0 years of age with defecation disorders, perianal pain, local itch, rectal bleeding, or fissure and a sharply demarcated perianal redness. Perianitis is associated with a streptococcal tonsillopharyngitis in about every fifth case. The time to diagnosis is ≥3 weeks in 65% of cases. Recurrences occur within 3½ months in about 20% of cases. An asymptomatic group A streptococcal throat carriage occurs in 63% of cases. As compared with perianal Streptococcus A culture, the rapid streptococcal tests have a positive predictive value of 80% and a negative predictive value of 96%. It is hypothesized that digital inoculation from nasopharynx to anus underlies perianitis. Many cases are likely caused directly by children, who are throat and nasal carriers of Streptococcus A. Some cases might occur in children, who have their bottoms wiped by caregivers with streptococcal tonsillopharyngitis or carriage of Streptococcus.Conclusion: Perianitis is an infection with a distinctive presentation and a rather long time to diagnosis. There is a need for a wider awareness of this condition among healthcare professionals. What is Known: • Group A Streptococcus may cause perianitis in childhood. • Systemic antimicrobials (penicillin V, amoxycillin, or cefuroxime) are superior to topical treatment. What is New: • The clinical presentation is distinctive (defecation disorders, perianal pain, local itch, rectal bleeding, or fissure and a sharply demarcated perianal redness). • The time to diagnosis is usually ≥3 weeks. Recurrences occur in about 20% of cases.