NEWPORT BEACH, CALIF. — Tinea capitis is the most common dermatophytic infection of childhood, Sheila Fallon Friedlander, M.D., said at the annual meeting of the Pacific Dermatologic Association.
She answered common questions posed by primary care physicians about the condition:
▸ Which organisms are most likely to cause tinea capitis? In the United States, Trichophyton tonsurans accounts for most cases, said Dr. Friedlander, a pediatric dermatologist at the University of California, San Diego, Healthcare system. Microsporum canis is occasionally seen, and usually is transmitted from a household pet.
However, in other countries, other organisms may cause tinea capitis, which is something to keep in mind when examining a child who immigrated from abroad, has recently traveled abroad, or who was adopted from a foreign country.
▸ What is the treatment of choice? Treatment should consist of oral griseofulvin plus a topical antifungal agent. Dr. Friedlander recommends starting griseofulvin at a dose of 20 mg/kg, which is higher than the standard dose but produces the best cure rates. A lower dose is “an inappropriate treatment for tinea capitis,” she said.
Evidence is accumulating that terbinafine (Lamisil), given at 3–6 mg/kg, is as safe and effective as griseofulvin and acts within 2 weeks. Enhanced efficacy has been seen with higher dosing of terbinafine (5–8 mg/kg per day). Some studies have documented good response with itraconazole (Sporanox) and fluconazole (Diflucan).
▸ How long should treatment last? In her practice, Dr. Friedlander usually treats for 8 weeks. Many experts recommend treating until 2 weeks after resolution of symptoms, which may require weeks to months of therapy.
▸ What do you tell parents about griseofulvin? Griseofulvin is inexpensive and has a long track record of efficacy. It is a relatively safe drug, but about 30% of patients develop side effects that include headache, gastrointestinal upset, and photosensitivity.
▸ Are laboratory tests necessary? Lab tests are needed only if the patient requires more than 8 weeks of treatment.
▸ Do you treat the entire family? Ask about other family members and treat them if they are symptomatic. T. tonsurans is commonly passed among wrestlers. Infection with M. canis should lead to questions about the family pet, as cats and dogs frequently harbor these organisms.
Some family members may insist on treatment even when they are asymptomatic. Dr. Friedlander prescribes topical therapy to reassure them.
▸ Do you prescribe prednisone for kerions? Most patients don't need prednisone. Kerions (nodular, exudative, circumscribed tumefactions covered with pustules) usually respond to antifungal therapy.
“We recommend adjunctive topical antifungal therapy, but rarely utilize the systemic therapy,” Dr. Friedlander said. If the patient doesn't improve within 2 weeks, Dr. Friedlander said she will add systemic therapy, but in most cases that isn't necessary.