Clinical Insights and Prognostic Factors in Frontal Fibrosing Alopecia and Lichen Planopilaris: A Retrospective Cohort Study

BACKGROUND: Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) share histopathology but differ in presentation, course, and treatment patterns. OBJECTIVES: To compare clinical characteristics, treatments, outcomes, and prognostic factors between LPP and FFA. METHODS: A retrospective cohort study was conducted at Sheba Medical Center, Israel (2010-2023). Patients with LPP or FFA followed for ≥1 year were included. Remission was categorized as early (≤12 months) or late (>12 months). RESULTS: 141 patients were included (81 LPP, 60 FFA). FFA showed greater female predominance (96.7% vs. 80.2%, p=0.004), older age at onset (56.9 ± 12.2 vs. 49.1 ± 14.1 years, p<0.001) and higher postmenopausal proportion (81.8% vs 44.4%, p=0.004). LPP patients more frequently reported pain (50.6% vs 6.7%) and pruritus (82.7% vs 36.7%) (both p<0.00001). Cumulative remission was higher in FFA than in LPP (68.3% vs 45.7%, p=0.022), whereas early remission rates and time to remission were similar (22.8 ± 17.6 vs 22.9 ± 20.5 months, p=0.98). Relapse rates were similar during treatment (22.0% vs 16.2%, p=0.59) and after discontinuation (29.3% vs 27.0%, p=0.83). In exploratory prognostic analyses, mild baseline severity was the most robust predictor of early remission in LPP. Other associations identified in the original multivariable models, including statin use, rural residence, and tetracycline treatment in FFA, and Ashkenazi Jewish ethnicity in LPP, did not remain significant after Bonferroni correction and should be interpreted as exploratory. CONCLUSIONS: FFA had higher cumulative remission than LPP despite similar time to remission and relapse rates. Prognostic associations require cautious interpretation and prospective validation.