A 73-year-old woman with a history of systemic lupus erythematosus (SLE), predominantly affecting the joints, and palmoplantar pustulosis visited our department with a plaque of alopecia on the scalp that had appeared a year earlier, coinciding with an episode of SLE (Fig. 1).

Figure 1.

Alopecia plaque with diffuse scaling and underlying erythema.

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[[?]]What is your Diagnosis?

Tinea capitis.

We report the case of a 73-year-old woman with a history of alopecia plaques that had appeared a year earlier. The plaques of alopecia have poorly demarcated edges and intense, thick desquamation. A polarized-light dermoscopy study revealed abundant comma hairs (arrow) and curly hairs (*) associated with broken hairs (arrow tip) and intense desquamation (Fig. 2).

Figure 2.

Dermoscopy showing comma hairs (arrow) and curly hairs (*) associated with broken hairs (arrow tip).

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The presence of these dermatoscopic structures led to the clinical suspicion of tinea capitis, which was subsequently confirmed from a culture of scales from the lesion, from which Microsporum canis was isolated. Treatment was instated with itraconazole at a dosage of 100 mg per day for a month, with resolution of the lesions.

Comma hairs and broken hairs were initially reported as markers for tinea capitis due to Microsporum canis.1 Subsequent publications described corkscrew hairs in infections by Microsporum and in infections by Trichophyton.2,3

The main differential diagnoses include other scaly erythematous skin disorders, such as seborrheic dermatitis, psoriasis, lupus erythematosus discoides, and lichen planopilaris. Lupus discoides is characterized by the presence of red spots and follicular plugs, which subsequently evolve into the loss of follicular ostia. Lichen planopilaris is characterized by erythema and perifollicular hyperkeratosis that evolves into erythematous areas without follicular ostia.4 Psoriasis of the scalp is characterized by its vascular pattern on dermatoscopic examination, with forked or looped vessels.5

Tinea capitis is characterized by broken hairs, comma hairs and corkscrew hairs associated with desquamation of the scalp. This pattern is useful for the differential diagnosis with other scaly erythematous disorders of the scalp, such as lupus discoides or psoriasis.

The authors declare that they have no conflicts of interest.