Eccrine duct dilatation in neutrophilic scarring alopecias

Background Eccrine duct dilatation (EDD) has been noted to occur significantly more often in primary lymphocytic scarring alopecias compared with non‐scarring alopecias, thus serving as a possible histopathologic marker for primary scarring alopecias with a lymphocytic infiltrate. This study aims to determine the presence and role of EDD in primary neutrophilic scarring alopecias. Methods We performed a retrospective review comparing primary scarring alopecia (neutrophilic, n = 90; lymphocytic, n = 100) and non‐scarring alopecia (n = 123) for presence of EDD, seen in Boston University School of Medicine between 2013 and 2017. Results EDD was more commonly seen in primary neutrophilic scarring (62.2%, 56/90) and primary lymphocytic scarring alopecias (54.0%, 54/100) than in non‐scarring alopecias (25.2%, 31/123) (P