Miniaturization of sebaceous glands: A novel histopathological finding in pemphigus vulgaris and pemphigus foliaceus of the scalp.

Background: Intraepidermal acantholysis is a characteristic histopathological feature of pemphigus. The histopathology of scalp biopsies in pemphigus has not been widely discussed in the literature, although the scalp is commonly involved in pemphigus.

Methods: A total of 32 consecutive patients with scalp involvement (17 with pemphigus vulgaris [PV] and 15 with pemphigus foliaceus [PF]) were enrolled into the study. The histopathological examination of scalp biopsies was performed in all patients. Tissue specimens were stained with hematoxylin and eosin.

Results: Acantholysis extended down the entire length of the outer root sheath of the hair follicle in 12 of 17 (70.6%) patients with PV. Follicular acantholysis in PF was restricted to the infundibulum and occurred in 12 of 15 (80.0%) patients. Acantholysis in the vellus hair follicles was observed in 12 of 17 (70.6%) and 9 of 15 (60.0%) cases, respectively. The miniaturization of sebaceous glands was seen in 14 of 17 (82.4%) and 12 of 15 (80.0%) patients, respectively.

Conclusions: Follicular acantholysis is a common histopathological feature of pemphigus. It may serve as a clue to the diagnosis of pemphigus subtypes, as PV and PF differ in the depth of follicular acantholysis. The miniaturization of sebaceous glands is a common histopathological feature observed in scalp specimens of patients with pemphigus.