Eccrine duct dilatation in neutrophilic scarring alopecias.

EDD is seen more frequently in primary scarring alopecias compared with non-scarring alopecias and usually found in sections containing inflammation and dermal fibrosis, serving as a possible histopathologic clue for a scarring process. Non-scarring alopecias have significantly fewer but considerably larger EDD which, may imply a different pathologic cause.