Isolated zosteriform acquired collagenoma: a report of three cases

Connective tissue nevi is a rare type of dermal hamartoma composed of collagen, elastin, or glycosaminoglycan. Isolated collagenomas, a type of collagen connective tissue nevi with unknown etiology, are sporadic, localized, solitary acquired collagen localized to any part of the body and unrelated to any disease. Here, we report three cases of the nonfamilial type of collagenoma without syndromic association, diagnosed based on clinical, dermoscopic, and histopathogical findings, due to its rarity.