By Gary M. White, MD
Note the scaly plaque with hair loss in a child.
Tinea capitis represents a fungal infection of the scalp. It typically affects young, often black children. In North America, Trichophyton tonsurans has replaced M. canis and M. Audouinii as the predominate dermatophyte. Unfortunately, T. tonsurans is Wood's light negative.
There are several clinical patterns including a seborrheic dermatitis-like pattern consisting mainly of scale, a black dot pattern where the hair is broken off at the base resulting in multiple black dots, and a kerion which is where there is so much inflammation, a boggy, swollen nodule forms. The patient may have acquired the organism through contact with other humans, animal, or fomites (inanimate objects). When a kerion is present, lymphadenopathy as well as a secondary eczema are not uncommon (called dermatophytid). Kerion celsi is an inflammatory form of tinea capitis caused by a T-cell–mediated hypersensitivity reaction to the causative dermatophyte.
Scalp lesions should be sampled by scalpel scraping, hair pluck, brush or swab as appropriate. With regard to the differential of localized hair loss on the scalp, one should consider alopecia areata, trichotillomania, lupus vulgaris and pseudopelade. The likelihood of tinea capitis is extremely high in a child with alopecia and lymphadenopathy [Arch Pediat Adol Med 1999;153;1150].
In the case of a kerion or a highly suggestive clinical presentation, therapy may be given immediately. Otherwise waiting for culture and identification of the organism is recommended. Terbinafine (2-4 weeks) and griseofulvin (8 weeks) are equally effective for infections by Trichophyton and Microsporum species [JAAD 2017;76;368].
Griseofulvin has been used effectively for years. 8 weeks of treatment are often needed. For griseofulvin microsized (e.g. Grifulvin V), give 20-25 mg/kg/day. For adults/over 50 kg, max 500 mg BID (1 gram/day). For griseofulvin ultramicrosized, give 15 mg/kg/day. Griseofulvin is contraindicated in pregnancy.
Terbinafine by body weight is given for 2-4 weeks
|< 20 kg||62.5 mg/day|
|20-40 kg||125 mg/day|
|> 40 kg||250 mg/day|
Itraconazole is given 50-100 mg/day for 4 weeks or 5 mg/kg/day for 2-4 weeks. It has been shown to be safe for use in the first year of life.
Fluconazole 6 mg/kg/day for 20 days has also been recommended by some. Fluconazole has also been given 8 mg/kg once weekly for 8-12 weeks [BJD 2000;142;965].
One may also have the patient and any suspected carriers use ketoconazole 2% shampoo 3/week. OTC selenium sulfide shampoo is an alternative. Oral ketoconazole should NOT be used due to the risk of severe hepatotoxicity.
It has been recommended that the itraconazole liquid not be used in children because of a safety concern with regard to one of its ingredients.
In some cases, an id reaction develops during treatment with an oral antifungal medication. The appearance is that of a fine papular rash and it should be distinguished from a true allergic drug reaction. In the case of an id reaction, the medication may be continued. Also, a secondary eczematous reaction may be present before any treatment is begun, particularly in the case of a kerion.
Kerion. Photographs courtesy of O. Dale Collins, MD and Dr. Kaess.
Kerion with typical lymphadenopathy. N Engl J Med 2012; 366:1142
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