Juvenile xanthogranuloma of the proximal nail fold.

An 18-month-old Caucasian boy presented with a firm 0.5 mm nodule, pink-red in color, with a yellow hue and some telangiectases on the surface, localized on the right thumbnail. The nodule involved all of the proximal nail fold and covered the proximal third of the nail. Pathology showed a dense dermal infiltrate of histiocytes, some of which had foamy nuclei, and multinucleated Touton giant cells. The lesion progressively decreased in size and had completely disappeared after 3 years. Periodic follow-up was important not only to monitor evolution of the juvenile xanthogranuloma, but also to avoid excessive growth of the lesion with possible definitive nail matrix damage.