Lichen planopilaris: Epidemiology and prevalence of subtypes - a retrospective analysis in 104 patients.

BACKGROUND: Management of patients with lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) is rendered difficult as robust epidemiologic data, insights on pathogenesis, associated diseases, possible relevance of concomitant medications or environmental factors are lacking.

PATIENTS AND METHODS: Retrospective analysis of demography, skin status, concomitant medication and diagnostic procedures were performed on 104 medical records (71 classic LPP, 32 FFA, and one Graham-Little-Piccardi-Lassueur syndrome).

RESULTS: Women were more often affected (distribution F: M classic LPP 4.9: 1; FFA: 31: 1). Compared to LPP patients, patients with FFA were significantly older (p < 0.001), more often postmenopausal, and more frequently on hormone replacement therapy. No other specific associations were identified. An association with lichen planus, other autoimmune diseases, or hepatitis virus infection was found only in individual patients. Clinically, FFA patients were significantly more often reported to have reduced eyebrows (p < 0.005), axillary, and/or pubic hair (p = 0.050).

CONCLUSIONS: The findings obtained from this study, with currently largest LPP/FFA patient cohort in Germany, encouraged us to set up a national FFA patient registry. Prospective data collected from larger numbers of patients with standardized questionnaires will help to assess assumed associations and influencing factors and to develop, in the long-term, recommendations for diagnosis and treatment.