Primary scarring alopecia: A retrospective study of 89 patients in Taiwan

Primary scarring alopecia (PSA) is caused by irreversible damage to the hair epithelial stem cells that reside in hair follicles. There is limited published work regarding PSA amongst the Asian population. The aim of this study was to evaluate the clinical features and to characterize the subtypes of PSA in southern Taiwan. In this retrospective case series, we reviewed 89 patients with pathology-confirmed PSA. The data was collected from National Cheng Kung University Hospital between 1988 through 2016. The clinical and histological data were reviewed, and the patients were characterized into different subtypes of PSA based on the clinical features and histological findings. We noted seven different subtypes of PSA. The most common type was dissecting cellulitis (DC) (30.3%), followed by lichen planopilaris (LPP) (23.5%), central centrifugal cicatricial alopecia (CCCA) (12.4%) and acne keloidalis nuchae (AKN) (12.4%). The other subtypes include folliculitis decalvans (FD), discoid lupus erythematosus (DLE) and pseudopelade of Brocq (PPB). Interestingly, FD, DC and AKN were more common in males, while CCCA, LPP, DLE and PPB had a female predominance. The mean age of patients with DLE, DC and AKN were younger, while patients with CCCA, LPP, PPB and FD tend to be older. The pattern of hair loss was more likely to be unifocal-ragged border in CCCA and DLE, multifocal-interconnected in LPP and FD, and multifocal-separated in DC. The pathogenesis of PSA may be influenced by sex, age and genetic background. It is important to identify the hair loss pattern to differentiate the subtypes of PSA.