A case of eruptive collagenoma localized on the neck and shoulders.

A 78-year-old woman, who had first noticed asymptomatic eruptions on her neck and shoulders eight years earlier, presented with papules and nodules 2 to 20 mm in diameter that had a normal to white hue and were flatly elevated. These lesions were scattered and multiple, some forming confluent plaques. Histopathologically, the epidermis was slightly atrophied, and collagen fibers in the dermis were coarse and proliferated. In addition, the number of elastic fibers was slightly decreased. No complications were evident. Based on these findings, the patient was given a diagnosis of mild eruptive collagenoma, a type of connective tissue nevus according to the classification of Uitto. This case is unique in that onset was at an advanced age and that distribution was localized on the neck and shoulders.