A 53-year-old man presents with a skin rash centered around his umbilicus. He describes slight itching and burning and denies symptoms elsewhere. The patient lists his medical history as including “borderline” diabetes. The rash was diagnosed elsewhere as an intertrigo, but the condition failed to respond to a 3-week course of betamethasone dipropionate/clotrimazole cream. The man was subsequently treated with ketoconazole cream and oral terbinafine, again without resolution of symptoms. Examination reveals a well-demarcated zone of erythema about the umbilicus; slight erythema about the rectum is noted as well.
Submit your diagnosis to see full explanation.
Perianal streptococcal dermatitis was first reported in the pediatric literature in 1990.1 Occasional cases have been described in adults, with some involving the umbilicus.2 The condition is most common in males and is usually caused by group-A beta-hemolytic Streptococcus species, although both Staphylococcus aureus and non-group-A beta-hemolytic Streptococcus species have been implicated.3,4
Unlike an acute bacterial infection, perianal and periumbilical infections are characterized by chronicity and lack of warmth and tenderness. The condition manifests as a well-circumscribed zone of erythema that is either asymptomatic or pruritic. Common misdiagnoses include fungal infection and psoriasis.2 Diagnosis is confirmed by culture results, and treatment with oral ampicillin or oral penicillin allows rapid resolution of the condition.
Based on treatment history and clinical appearance, a presumptive diagnosis of periumbilical streptococcal infection is made. The patient is placed on oral penicillin and, when seen in follow-up examination 2 weeks later, had experienced full resolution of rash.
Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.
1. Krol AL. Perianal streptococcal dermatitis. Pediatr Dermatol. 1990;7:97-100.
2. Kallini JR, Cohen PR. Perianal and periumbilical dermatitis: report of a woman with group-G streptococcal infection and review of perianal and periumbilical dermatoses. Dermatol Online J. 2013;19:3.
3. Heath C, Desai N, Silverberg NB. Recent microbiological shifts in perianal dermatitis: Staphylococcus aureus predominance. Pediatr Dermatol. 2009;26:696-700.
4. Brazilai A, Choen HA. Isolation of group-A streptococci from children with perianal cellulitis and from their siblings. Pediatr Infect Dis J. 1998;17:358-360.