The Use of Direct Immunofluorescence in Frontal Fibrosing Alopecia.

BACKGROUND: Frontal fibrosing alopecia (FFA) differs from lichen planopilaris (LPP) in many clinical aspects, but histology fails to distinguish between these entities. Direct immunofluorescence (DIF) is a diagnostic technique used for autoimmune diseases, including those affecting skin and hair.

OBJECTIVE: To characterize DIF patterns in patients with FFA.

METHOD: Data was collected retrospectively from FFA cases presenting to the Centre de Santé Sabouraud Hair Clinic in Paris from November 2013 to November 2014.

RESULTS: Of 149 patients with FFA, 44 cases underwent DIF. Thirteen cases showed positive results with DIF. Patterns characteristic of LPP and lupus erythematosus were observed, with nearly half showing nonspecific staining.

CONCLUSION: DIF patterns in patients with FFA were variable. This diagnostic technique should be used with caution in cases of cicatricial alopecia, particularly FFA.