May 2005

A 10-year-old black boy developed a scaling scalp rash approximately five months ago. No hair loss was noted, and he was treated with hydrocortisone lotion and selenium sulfide shampoo for presumed seborrheic dermatitis. Over the next few months he developed subtle hair loss, and subsequently his mother noted a big red swollen bald spot on the vertex of the scalp. He was then treated with griseofulvin micro-sized 11 mg/kg/day. The swelling went down after three weeks, but even after eight weeks, he still has some other smaller spots of hair loss, and big lymph nodes in his neck. The patient has been taking his griseofulvin with soda, and mom wants to stop the medicine. She thinks he may have been allergic to it initially, because he broke out in a rash the first few weeks he was on the drug. What do you think?

Answer

This young man has tinea capitis that has been inadequately treated with a suboptimal dose of griseofulvin. The dermatologist confirmed the diagnosis by scraping scalp hairs which revealed arthrospores within the hair shaft.

Tinea capitis is a dermatophyte infection that most commonly afflicts pre- and early school age (3-7) children. A recent investigation conducted in Cleveland, Ohio urban elementary grade schools documented a 5% prevalence rate, and an additional 8% of children evaluated were culture positive but asymptomatic.

Our patient is most likely infected with Trichophyton tonsurans, which accounts for 95% of disease in the United States. This dermatophyte is transferred from person to person, and, therefore, investigation of the patient’s family members and contacts are in order. If any of them has symptoms, they should be cultured, as should the index case. Another form of dermatophyte, Microsporum canis, can cause scalp infections, and is transmitted by cats and dogs. M. canis accounts for only 5% of disease in the United States, but can be quite difficult to eradicate. Wood’s lamp evaluation is positive with M. canis infections, but negative if the patient is infected with T. tonsurans.

Our patient initially presented with scalp scaling as his only symptom, according to his mother. This can occur with T. tonsurans infections, and therefore misdiagnosis and inappropriate treatment with steroid preparations may occur. Associated head and neck lymphadenopathy, though not diagnostic, raises the index of suspicion for tinea capitis, and the need for culture documentation.

When hair loss was noted, the patient was treated with a suboptimal dose of griseofulvin. Although the PDR recommends this dose, recent evidence documents that such dosing is likely to lead to a poor cure rate, and most experts recommend 20-25 mg/kg/day microsize formulation (maximum 1 gr) for at least eight weeks, given with fatty foods to increase absorption. Our patient’s predilection to take the drug with soda further decreases his chances of obtaining optimal systemic drug concentrations.

Itchy, eczema-like eruptions frequently occur in patients with tinea capitis, and are often misdiagnosed as a drug eruption. A true drug reaction (which is unlikely with griseofulvin) would mandate a change in therapy. Therapeutic options include itraconazole (Sporanox, Janssen), fluconazole (Diflucan, Pfizer) and terbinafine (Lamisil, Novartis), though all such uses would be considered off-label. A recent meta-analysis of randomized controlled trials comparing griseofulvin and terbinafine found that two to four weeks of terbinafine was as efficacious as six to eight weeks of griseofulvin. The optimal dose of terbinafine is unclear, and precision is hampered by the fact that only a 250 mg tablet formulation exists. Studies have shown that a duration of two to four weeks may be sufficient for treatment, and a dose of 5-6 mg/kg/ day (maximum 250 mg) would be likely to lead to a good response.

Laboratory studies are not necessary if a patient is asymptomatic and responds to therapy within eight weeks. CBC and LFTs are appropriate if more prolonged therapy is required. The other therapeutic options mentioned are not, yet, FDA-approved for children, and the need for laboratory evaluation is undetermined. However, thus far all of the options mentioned appear to have a good safety profile in children

The patient may return to school as soon as therapy is initiated. Topical adjunctive antifungal therapy is likely to lead to a decreased time in which the patient sheds infective spores, and is recommended. Topical shampoos such as selenium sulfide, ketoconazole (Nizoral, McNeil), and ciclopirox are options. Hairstyles may prohibit frequent shampooing, but twice a week is the usual recommended intervention for topical therapy.

Infective spores are quite hardy, and headgear, hats and hair grooming items should be washed frequently; sharing of such items should be discouraged.

Some experts recommend topical antifungal therapy for all family members, due to the likelihood that such contacts may well be colonized or infected. Occasionally adult caretakers may be infected, and difficulty in curing a patient raises concern regarding exposure to other infected individuals with re-infection. In such cases, all family members should be evaluated for disease or colonization. This patient also had a severe inflammatory response to the infection, termed a kerion. It is controversial whether systemic steroids are useful for such lesions. Many experts initiate systemic antifungal therapy, and observe response. If the boggy swelling does not abate, one could institute two weeks of systemic corticosteroid therapy. Fortunately, with our patient the swelling decreased rapidly, and steroids were not indicated.

For more information:

• Ghannoum MA, et al. Tinea capitis in Cleveland: survey of elementary school students. J Am Acad Dermatol. 2003;48(2):189-93.
• Fleece D, et al. Griseofulvin versus terbinafine in the treatment of tinea capitis: a meta-analysis of randomized, clinical trials. Pediatrics. 2004;114(5):1312-5.
• Friedlander SF, et al. Terbinafine in the treatment of Trichophyton tinea capitis: a randomized, double-blind, parallel-group, duration-finding study. Pediatrics. 2002;109(4):602-7.
• Williams JV, et al. Prevalence of scalp scaling in prepubertal children. Pediatrics. 2005;115(1):e1-6.