From the Research
Perianal streptococcal infection is diagnosed through clinical examination and bacterial culture, and treated with oral antibiotics, typically penicillin or amoxicillin, with a first-line treatment of oral penicillin V (250-500 mg three times daily for children, depending on weight) or amoxicillin (50 mg/kg/day divided three times daily) for 10 days, as supported by the most recent study 1.
Diagnosis
The diagnosis is made by identifying the characteristic bright red, well-demarcated perianal erythema, often accompanied by pain, itching, rectal bleeding, and constipation. A bacterial culture from the perianal area confirming group A beta-hemolytic streptococcus (GABHS) is definitive.
- Clinical symptoms such as painful defecation, anal fissures, and macroscopic blood in stools are highly suggestive of group A streptococcal perianal infection, with a probability of 83.3% 2.
- Rapid diagnostic testing has a high sensitivity of 98% but relatively low specificity of 72.8% 2.
Treatment
For penicillin-allergic patients, alternatives include erythromycin (40 mg/kg/day divided four times daily), azithromycin (12 mg/kg once daily for 5 days), or clindamycin (20-30 mg/kg/day divided three times daily).
- Topical mupirocin may be used as adjunctive therapy but is insufficient alone.
- Symptoms typically improve within 24-48 hours of starting antibiotics, but completing the full course is essential to prevent recurrence.
Epidemiology
This infection occurs most commonly in children aged 6 months to 10 years and is caused by the same organism responsible for strep throat, spreading through fecal-oral contamination or autoinoculation from pharyngeal infection.