Trichoscopy of Pemphigus Vulgaris and Foliaceus on Black Scalp.

Introduction: Pemphigus foliaceus (PF) and pemphigus vulgaris (PV) are bullous diseases characterized by loss of keratinocyte adhesion, easily ruptured blisters, and erosions. The scalp is involved in up to 60% of patients due to the high concentration of antigens in hair follicles. Trichoscopy has been studied in bullous diseases. However, research on pemphigus trichoscopy remains scarce. This study aimed to analyze the main trichoscopic features of pemphigus on the black scalp, a topic poorly appraised thus far.

Methods: Ten male and 8 female patients were enrolled, evenly distributed between PV (aged 16-59) and PF (aged 20-72), with Fitzpatrick phototypes equal to or greater than IV. Scalp evaluations were conducted using digital dermoscopy, with 20-to-70-fold magnification. Our results were compared with original research on Caucasian scalp pemphigus.

Results: Our study identified the previously published and also novel trichoscopic features. Our patients exhibited higher percentages (p < 0.05) of eight classic structures, considering both PF and PV; PF only; PV only. Aside from yellow dots (p = 0.002), our sample showed no statistically significant differences between the PV and PF groups in black patients.

Conclusion: Peculiarities of black scalp trichoscopy did not interfere in the diagnosis of pemphigus. Trichoscopy should be a routine diagnostic tool in patients with bullous scalp diseases, especially in the early stages, and to guide biopsy. To our knowledge, this is the first study focused on trichoscopy of pemphigus affecting black scalp. It indicates that, among other findings, yellow dots may be a relevant hallmark of scalp PV.