Association of dermal melanocytosis with lysosomal storage disease - Clinical features and hypotheses regarding pathogenesis

Background: The potential association of dermal melanocytosis with lysosomal storage disease in infancy is an uncommonly known and poorly understood entity. Observations: We describe 2 infants with extensive dermal melanocytosis in association with GM(1) gangliosidosis type 1 and Hurler syndrome, respectively. A literature analysis revealed 37 additional cases. Clinically, dermal melanocytosis associated with lysosomal storage disease is characterized by extensive, blue cutaneous pigmentation with dorsal and ventral distribution, indistinct borders, and persistent and/or "progressive" behavior. GMI gangliosiclosis type 1 and Hurler syndrome are the most common underlying disorders associated with these cutaneous features. Conclusions: In the appropriate clinical setting, an unusual presentation of dermal melanocytosis in an infant may be a cutaneous sign of an underlying lysosomal storage disease. The pathogenetic mechanisms behind this association remain to be elucidated.