Perianal streptococcal cellulitis is a skin infection caused by group A streptococcus. It presents with a significantly warm and erythematous rash with a well-demarcated border in the perianal region. This may be associated with fissures or bleeding and can cause increased pain with defecation. Additional symptoms such as itching or desquamation may also be noted. There are no associated satellite lesions throughout the diaper area as seen in candidal dermatitis. Children and infants are most affected. A rapid strep swab of the area can be used to confirm the diagnosis. Treatment consists of oral antibiotics.