Key Clinical MessageConnective tissue nevus is a hamartoma composed of excess amounts of one or several components of the dermis, such as collagen, elastin, and proteoglycans. This report introduces a 14‐year‐old girl with grouped flesh color papules and skin color nodules distributed unilaterally with a dermatomal pattern. These lesions involved more than one segment. Histopathology is the gold standard for diagnosing collagenoma and mucinous nevus. We reported the first case of mucinous nevus with multiple collagenoma that shows the specific clinical features.