LAS VEGAS – Competition among large retailers is bringing down the cost of terbinafine, but griseofulvin is still better for many fungal infections, according to Dr. Lawrence F. Eichenfield.
The ideal prescription depends on the type of fungus and the site of the infection, Dr. Eichenfield, chief of pediatric and adolescent dermatology at the University of California, San Diego, said at the update, sponsored by the American Academy of Pediatrics California Chapter 9.
Topical medications alone can seldom cure tinea capitis because the fungus finds protection inside hair follicles, but he advised using them in combination with systemic drugs.
Signs of tinea capitis include scaling, pustules, kerion, black dots, alopecia, adenopathy, and autoeczematization (also known as id reaction). The condition can resemble seborrheic dermatitis, psoriasis, folliculitis, and other diseases.
“So it's worth doing a routine culture,” said Dr. Eichenfield, adding that it's fairly easy to obtain a specimen with a toothbrush, cotton swab, or bacterial culturette.
The most common culprit is Trichophyton tonsurans, spread by human contact. The second most common cause is Microsporum canis, spread by cats.
Family coinfection can contribute to treatment failure, so inquire about tinea capitis and tinea corporis in other affected family members and pets, said Dr. Eichenfield. Standard therapy for tinea capitis is microsized griseofulvin (20 mg/kg) for 6–8 weeks, he advised.
The only other approved drug is terbinafine granules, and these are hard to obtain, he said, but itraconazole and fluconazole might work.
Particularly if griseofulvin fails, Dr. Eichenfield recommended terbinafine 4–8 mg/kg per day for 4 weeks. But one study found that griseofulvin was much better than terbinafine for M. canis (J. Am. Acad. Dermatol. 2008;59:41-54).
The same organisms, along with T. rubrum and T. mentagrophytes, can cause tinea corporis. Patients present with red scaling plaque, often with an active border. Central clearing may give the lesions a ring shape. They can be treated with topical drugs, including clotrimazole, econazole, oxiconazole, ciclopirox, terbinafine, and ketoconazole.
Systemic treatment should be reserved for extensive disease or special circumstances, such as for wrestlers. The best systemic treatment is griseofulvin, 15–20 mg/kg (5–10 mg/kg ultramicrosize), he said.
Dr. Eichenfield said he had no relevant financial disclosures.
'So it's worth doing a routine culture' for tinea capitis.
Source DR. EICHENFIELD