Trigeminal Somatosensory Dysfunction in Frontal Fibrosing Alopecia: A Cross-sectional Quantitative Sensory Testing Analysis

ABSTRACT Frontal fibrosing alopecia (FFA) is a primary cicatricial alopecia commonly accompanied by scalp itch, pain, or burning. We aim to characterize the sensory profile of FFA patients using quantitative sensory testing (QST) and compare them with healthy controls. This cross-sectional study included 28 females: 14 FFA patients and 14 controls. All participants underwent a standardized battery of eight QST parameters: cold and warm detection thresholds (CDT, WDT), cold and heat pain thresholds (CPT, HPT), mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind-up ratio (WUR), and pressure pain threshold (PPT). Testing was conducted at both clinically affected and unaffected forehead sites. FFA patients showed sensory dysfunction at affected and unaffected sites, with greater abnormalities in affected sites, including thermal and mechanical deficits. Compared with controls, mechanical detection (MDT, p = 0.026) and pressure pain thresholds (PPT, p = 0.003) were significantly altered. The modest sample size limits statistical power, and the cross-sectional observational design limits generalizability and causal inference. FFA may be associated with both localized and widespread sensory dysfunction, suggesting a potential neural component in its pathogenesis. QST could serve as a valuable tool for identifying sensory alterations in FFA, potentially informing the development of future therapeutic interventions.