Pemphigus vulgaris and pemphigus foliaceus are autoimmune blistering diseases of the skin and the mucous membranes caused by autoantibodies directed against desmosomal glycoproteins desmoglein 1 (Dsg1) and Dsg3, resulting in the loss of keratinocyte cell-to-cell adhesion. The typical histological features are intraepidermal acantholytic blister formation with acantholysis often extending from the epidermis down the outer root sheaths (ORS) of hair follicles.¹

Since hypothetically these immunodeposits should also be demonstrable in the ORS of plucked hair, our aim was to verify the practicability of direct immunofluorescence (DIF) on plucked hairs for diagnosing pemphigus.

Fifteen consecutive patients with pemphigus were voluntarily included in the study, irrespective of any other inclusion or exclusion criteria. Approximately 50 hairs from each patient were obtained in the same way as for the trichogram. The ORS were immediately shock frozen in liquid nitrogen and processed in the same manner as skin biopsies for DIF.² The fluorescence microscopy examination was performed in a blinded manner. In judging the immunofluorescence findings, the following scale of intensity was used: negative, indecisive, faint, distinct, and strong. Enzyme-linked immunosorbent (ELISA) studies for determining anti-Dsg1 and anti-Dsg3 levels were performed on all 15 patients' serum samples as described elsewhere.³