How would you treat his itchy, raised lesion breaking out?

An otherwise healthy 6-year-old male presented 2 months ago with an itchy scalp and hair loss. He went to his pediatrician who suspected tinea capitis and started him on oral griseofulvin at a dose of 15 mg/kg. Six weeks later, the lesion is now raised and crusted as noted with itching and pain. 

How would you diagnose the patient?

A. Resistant tinea capitis.

B. Kerion.

C. Secondary staphylococcal infection.

D. Pityriasis amiantacea.

E. Psoriasis.

(Answer and discussion on next page)

Answer—Kerion

These changes are consistent with a kerion. Trichophyton tonsurans is the most common cause of this inflammatory response to the underlying dermatophyte. Topical therapy is ineffective and often requires several months of griseofulvin therapy. Success has been reported with itraconazole, terbinafine, and fluconazole orally. 

Ketoconazole shampoo is recommended to treat the patient and exposed family members in order to avoid spread and relapse. Because of the slow response to antifungals, patients can progress for 2 to 3 weeks before improving. Some patients require higher doses of antifungal therapy. The Microsporum canis species can respond variably to antifungal therapies as well.