Sir,

The appearance of an inflammatory nodule on the scalp initially leads general practitioners to suspect bacterial origin, leading to puncture-aspiration or outright surgical excision. Herein, we report the case of a child who was mistakenly operated for a scalp abscess.

The patient was a three-year-old child with an inflammatory scalp nodule that developed over eight days, for which he consulted the pediatric emergency room, where he was treated surgically. As his condition did not improve, he was referred to our clinic for further treatment. We found domestic animals (pigeons, cats) during the interrogation, yet no similar cases in the family. A dermatological examination revealed irregularly sized, alopecic plaques with a rounded ulceration adjacent to the excision of the nodule. The traction sign was positive (Figs. 1a and 1b). Dermatoscopy showed an erythematous area with yellowish scales. The examination of the lymph nodes found three subcentimetric cervical adenopathies bilaterally. Mycological samples revealed colonization by Trichophyton violaceum. The sample was subjected to oral corticotherapy (1 mg/kg/d) for ten days, then to daily washing with a ketoconazole sachet and to oral and local griseofulvin with favorable results (Fig. 2).

	Figure: (a) Alopecic plaques involving the vertex, erosive with pus to pressure. (b) Rounded ulceration corresponding to the exeresis of the nodule.
	Figure 2: Healing of the ulceration with scarring alopecia.

Kerion is an inflammatory variant of the scalp ringworm caused by an exaggerated immune response to the fungus [1,2]. It begins as inflammatory follicular papules, gradually coalescing into a soft mass, destroying the hair follicles, thus potentially leading to scarring and alopecia [3]. However, because of the obvious inflammation of the hair follicle and the surrounding area, it is often misdiagnosed and treated as scalp pyoderma, anthrax, or cellulitis. Our patient had this problem.

Diagnostic criteria are proposed indicating a consultation with dermatology before surgical manipulation, and diagnosis includes culture, dermoscopic examination, and Wood’s lamp examination [2]. Treatment requires the use of oral antifungal agents with adjuvant topical treatments to prevent the spread of the infection. Incision and drainage aggravate the infection and delay the treatment of the disease [1,3].

Kerion is often misdiagnosed and mistaken for an abscess, which delays appropriate treatment and allows the infection to spread. Therefore, early diagnosis and prompt treatment may prevent scarring and psychological complications.