Perianal Streptococcal Dermatitis Complicated by Bacteremia: Report of Two Cases With Unusual Presentations

To the Editors: Perianal streptococcal dermatitis (PSD) is a superficial skin infection of perianal area, mostly caused by group A Streptococcus (GAS).1,2 It typically presents with well-demarcated perianal erythema, without fever or systemic symptoms.1–3 PSD is often misdiagnosed and patients receive unnecessary treatments for other conditions like diaper dermatitis.1–3 The use of various topical creams can alter the typical appearance, further complicating the diagnosis.2 While febrile PSD cases have been rarely reported,4 bacteremia has not been reported in association with PSD to date. This report presents 2 cases of PSD with unusual presentations, initially misdiagnosed as diaper dermatitis and complicated by bacteremia. CASE 1 A previously 18-month-old boy presented with fever and redness in the diaper area. Over the past week, he had been using topical creams containing hydrocortisone butyrate (0.1%) for diaper dermatitis. His family reported that the redness first appeared as perianal erythema but spread to the gluteal and genital areas after using topical creams. On examination, he had fever (38.9 °C), tenderness and erythema in the perianal, gluteal (Fig. 1A) and pubic areas (Fig. 1B). His 7-year-old brother had been diagnosed with GAS pharyngitis 1 week before his symptoms. Laboratory studies revealed a white blood cell count of 23.1 × 109/L with 85% neutrophils and C-reactive protein of 240 mg/L. He was hospitalized, and empiric intravenous (IV) ampicillin-sulbactam was initiated. On hospital day 2, both blood and perianal swab cultures were positive for GAS. His symptoms resolved rapidly, and he was discharged after 8 days of IV antibiotics, followed by 6 days of oral amoxicillin. Post-treatment blood and perineal swab cultures were negative. No recurrence was seen after 6 months.FIGURE 1.: Clinical photographs of patients with perianal streptococcal dermatitis. Erythema in the gluteal (A), and pubic (B) areas and perianal erythema (C).CASE 2 A previously healthy 9-year-old girl was admitted to our hospital with a 2-day history of fever and abdominal and perianal pain. She had been diagnosed with acute gastroenteritis and diaper dermatitis 3 days ago and was using topical creams containing diflucortolone valerate (1 mg) for the diaper dermatitis. On examination, she had fever (38 °C), abdominal tenderness, and warm, painful erythema in the perianal area (Fig. 1C). Laboratory studies revealed a white blood cell count of 19.7 × 109/L with 88% neutrophils and C-reactive protein of 208 mg/L. A rapid antigen test confirmed GAS from the perianal lesion, leading to a diagnosis of PSD. She was hospitalized, and IV cefuroxime was initiated. On hospital day 2, cultures from blood, urine and a perianal swab tested positive for GAS. After antibiotic treatment, the perianal pain and erythema resolved quickly; however, her fever persisted. Therefore, IV clindamycin was added to the treatment. Her fever subsided on day 3, and she completed 7 days of IV antibiotics and 7 days of oral amoxicillin-clavulanate. There was no growth in the follow-up blood, urine and perianal swab cultures. The most common sources of GAS bacteremia are skin and soft tissue infections, such as cellulitis/erysipelas, surgical wound infections and varicella virus infections.5 However, to our knowledge, no cases of bacteremia associated with PSD have been reported to date. Our cases highlight that GAS bacteremia may also be associated with PSD.