Answer to April 2014 Photo Quiz: Diagnosis and Treatment of Kerion

The document discusses the diagnosis and treatment of kerion, an exaggerated inflammatory response to tinea capitis, a fungal infection of the scalp and hair shaft. The differential diagnosis for the condition includes acute bacterial abscesses, alopecia folliculitis, and psoriasis. Due to the unreliability of clinical diagnosis alone, laboratory confirmation is necessary, which involves specimen collection through aspiration, the toothbrush method, or cotton swab method, followed by microscopic evaluation using potassium hydroxide and fungal stains, and culture on specific media. Treatment requires systemic therapy, with griseofulvin at 20 to 25 mg/kg/day being the gold standard, although itraconazole and terbinafine may also be effective. Mycological cure rates for a 6- to 8-week treatment course range from 70 to 100%. Adjunctive therapy with 2% ketoconazole or 1% selenium sulfide shampoo can reduce transmission risk. In the case presented, the patient was empirically started on griseofulvin and selenium sulfide shampoo, with follow-up planned in 4 weeks.