Agminated blue nevus over acne scars: coincidence or pathophysiological relationship?

Blue nevus is a benign lesion arising from dermal melanocytes containing large amounts of melanin. The agminated variant presents a cluster of blue nevus lesions with linear or blaschkoid distribution. We report two cases of patients with agminated blue nevus that developed on previous acne scars, and dermoscopy helped a lot in the differential diagnosis. This is the first occurrence found in the literature of agminated blue nevus that appeared on a previous scar, which may have occurred by chance or as a result of the collagen remodeling process inherent to the healing process.

Keywords: Scar; Collagen; Dermoscopy; Nevus blue