The boy in the vignette has a localized area of alopecia, redness, exudative discharge, and bogginess consistent with a kerion, an acute local inflammatory response to a tinea capitis infection. Griseofulvin, a benzofuran, is the systemic antifungal treatment of choice for kerion and other noninflammatory tinea capitis infections of the scalp. Cephalexin, a first-generation cephalosporin, would be appropriate if he had a confirmed or suspected bacterial skin or soft tissue infection. It has good coverage against methicillin-susceptible Staphylococcus aureus and group A Streptococcus , the 2 common gram-positive bacteria implicated in bacterial skin infections. Clindamycin offers the benefit of methicillin-resistant S aureus coverage. Intravenous vancomycin is generally reserved for severe or extensive skin and soft tissue bacterial infections.

The boy in the vignette was initially misdiagnosed with a bacterial scalp infection. His clinical findings of redness, swelling, and discharge could be consistent with a bacterial skin infection. However, the boy does not have any systemic signs of infection (eg, fever, malaise), or local pain or discomfort; he has localized alopecia and pruritus; the lesion is boggy and nontender; and he did not respond to amoxicillin clavulanate. These features are suggestive of a kerion.

Tinea capitis is one of the most common and highly communicable fungal infections of the scalp and hair shaft in children. The typical age at presentation is 3 to 9 years. It is more prevalent in children living in crowded conditions. Most tinea capitis infections are caused by a Trichophyton species dermatophyte, with Trichophyton tonsurans being the most common cause. Microsporum is responsible for the remainder of tinea capitis infections and is transmitted by pets.

Tinea capitis manifests along a spectrum of 5 clinical presentations:

Mild, with seborrhea and scaling, with or without hair loss ( Item C4 )

Pustular, with crusting, either localized or extensive

Black dots within areas of alopecia

A scaly annular patch of alopecia

Kerion, an inflammatory mass

Tinea capitis is primarily a clinical diagnosis. The presence of alopecia, scaling, pruritus, and posterior cervical lymphadenopathy is highly suggestive of the diagnosis. If the diagnosis is unclear, dermatoscopy with a lighted magnifier can be performed and may show corkscrew- or comma-shaped hair. A potassium hydroxide (KOH) wet mount of hair or scale from the affected area is a quick method to visualize hyphae. Fungal culture can establish the diagnosis.

Because tinea capitis is an infection of the root of the hair follicle, topical antifungals are ineffective. Griseofulvin has traditionally been the systemic oral antifungal agent of choice. The duration of therapy is 6 weeks. Other oral treatment options include terbinafine and fluconazole.

PREP Pearls

Kerion is an inflammatory reaction to a scalp tinea infection which presents as a large, hairless, red, and boggy area over the scalp.

Trichophyton is the most common cause of tinea capitis, followed by Microsporum species.

Tinea capitis is treated with a systemic oral antifungal agent such as griseofulvin, terbinafine, or fluconazole.

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