Name the four clinical patterns of tinea capitis.

1. Fig. 31.2 Tinea capitis. A, Seborrheic pattern. B, Black-dot pattern. C, Kerion presenting as a tender boggy mass in the scalp.

   The seborrheic pattern has a dandruff-like scaling of the scalp and should be considered in prepubertal children with suspected seborrheic dermatitis (Fig. 31-2A).
2. In the black-dot pattern, hairs are broken off at the skin line, and black dots are seen within the areas of alopecia (Fig. 31-2B). In the U.S., this pattern is primarily associated with T. tonsurans infections.
3. A kerion is an inflammatory fungal infection that may mimic a bacterial folliculitis or an abscess of the scalp (Fig. 31-2C). The scalp is tender to the touch, and the patient usually has posterior cervical lymphadenopathy.
4. Favus is a rare form of inflammatory tinea of the scalp presenting with sites of alopecia that have cup-shaped, honey-colored crusts, which are called scutula and are composed of fungal mats. Tinea capitis is one of the most commonly misdiagnosed skin infections. Any prepubertal child who presents with a scaly scalp dermatitis or carries a diagnosis of seborrheic dermatitis should be presumed to have a dermatophyte infection of the scalp until proven otherwise. Similarly, any child who presents with one or more scalp abscesses most likely has a kerion. Kerions are frequently secondarily infected with Staphylococcus aureus, and unsuspecting health care providers often mistakenly treat kerions as bacterial abscesses.

Sobera JO, Elewski BE : Fungal infections. In Bolognia JL, Jorizzo, JL, Rapini RP, et al, editors: Dermatology, New York, 2008, Mosby, pp 1135–1163.