Simultaneous occurrence of cutaneous mastocytosis and juvenile xanthogranuloma in a child: Random or true association?

Juvenile xanthogranuloma (JXG) and cutaneous mastocytosis (CM) are two distinct conditions that have rarely been reported in association. We report a child with CM and disseminated JXG, who showed a significant decrease in serum tryptase levels and regression of JXG lesions over time. Due to the paucity of reports, a true association between these two conditions has not been validated, although a potential induction of histiocytic lesions by mast cell degranulation has been proposed.