Tinea capitis is classically thought to be a pediatric condition.  However, it does occur in the active duty age group, especially black males.  The most common cause of tinea capitis in the 1990s is Trichophyton tonsurans.

Trichophyton tonsurans infection of the scalp can produce a variable clinical picture. Asymptomatic scaly patches containing tiny black dots with minimal hair loss frequently confused with Alopecia Areata is the most frequent presentation (figure 11) although large, boggy inflamed plaques sometimes occur (figure 12).  A Wood's light is of no use to diagnose Trichophyton tonsurans because this organism does not fluoresce.

Potassium hydroxide scrapings from the scalp should not be taken from the scale.  Instead, they should include the broken fragments of hair or the tiny black dots.  Use the tip of an 18-g needle.  A curette will function.  Be sure to let the preparation digest for several minutes (after gently heating) before viewing. 

Instead of  looking for branching hyphae, look for tiny athrospores (sometimes in chains) within and outside of the hair shaft fragments (figure 13).

Therapy of tinea capitis involves systemic antifungals (see below).  Topical therapy alone is inadequate, it will not adequately penetrate the hair follicles.  The use of an antifungal shampoo such as Selsun, Nizoral, or Head and Shoulders is good adjunctive therapy and will make your patient much less infectious to his/her shipmates.  Griseofulvin is still the drug of choice.  Oral treatment for at least 10 weeks is necessary.

(c)     Oral Antifungal Therapy

The use of oral antifungal therapy is frequently misunderstood by the primary care provider.  For now, griseofulvin is the drug of choice although this may change in the next year or two.  The newer generation of oral antifungals is quite costly and is frequently unavailable to deployed units.

Griseofulvin

Griseofulvin is a reasonably safe and effective drug in healthy patients if properly used.  Not all griseofulvin preparations are the same.  The bioavailability and doses of micro-size and ultra micro- size forms of griseofulvin are quite different.  Follow the PDR recommendations for dosing.  One exception however, is the need to use the "upper end" of the dosing scales for tinea capitis.

Gastrointestinal side effects and headache are the most frequent problems with griseofulvin.  These problems can usually be avoided if the drug is given with a meal, especially with some lipid.  A piece of toast with margarine or oil and vinegar on a salad will provide sufficient fat.  Bacon and eggs are not necessary.  Phototoxicity is unusual but reported.

Unlike antibacterial agents, griseofulvin works quite slowly.  The deposition of the drug in newly keratinizing epithelium allows it to work.  This takes time so be patient.  Pretreatment liver function tests repeated every month or two combined with a good follow up monthly will prevent significant hepatotoxicity.  Be aware of the interactions with coumadin and do not prescribe for patients with porphyria.

Ketoconazole

This oral form of this medication is of limited use for treating tinea.  This is best reserved for selected patients with candida or tinea versicolor.

Itraconazole (Sporanox)

This drug is very expensive.  The use of "pulse" therapy for the treatment of the nails (tinea unguium) is equally effective as daily therapy in most patients.  Use 200 mg twice a day (with food) for 7 consecutive days per month repeated for 3 or 4 months. Liver function tests are usually not needed for healthy patients using this "pulse" regimen.  The list of drug-drug interactions is very long for this medication.  Check the PDR for details.

Tebenafine (Lamasil)

This medication is also very expensive.  However, it does not have the long list of drug interactions as itraconazole.  The dose is 250 mg daily for 3-4 months.  Follow the PDR concerning patient monitoring.