Dermatitis artefacta simulating trichophytic ringworm.

Abstract

In this case we excluded trichotillomania, because all the hairs had the same length and alopecia areata for the rectangular shape and the absence of clinical and dermoscopic characteristic signs; the differential diagnosis from a trichophytic ring-worm was more difficult due to the presence of truncated hairs, but the rectangular shape of the affected area, the absence of inflammation, the fresh examination showing intact hairs, all of the same thickness, allowed us to exclude a ringworm of the scalp. Despite the positive mycological examination, we considered unlikely a superficial tinea due to the absence of inflammation, but we recommended topical antifungal therapy. It is known, however, that a positive culture for anthropophilic dermatophytes can be found in family members of patients (2) and in unrelated subjects (1). For exclusion and family history of the patient prevailed the suspicion of dermatitis artefacta.