[Increasing pigmentation in Schmidt syndrome (polyglandular autoimmune syndrome type II]

An 18-year old man presented with increasing pigmentation in multiple nevi as well as so-called "eruptive nevi" over a 24 month period. The first excisional biopsy was from a plantar nevus which showed melanocytic hyperplasia. Following excisions of both hyperpigmented and newly appearing nevi showed only increased pigmentation. Two years after the first examination Addison-like hyperpigmentation was noticed in typical locations. Both Addison disease and Hashimoto thyroiditis were then confirmed by elevated serum levels of ACTH, TSH, and decreased levels of cortisol and L-thyroxine. This confirmed the diagnosis of Schmidt syndrome as part of polyglandular autoimmune disease (PGAS) type II. After another 18 months of treatment with hormone substitution of L-thyroxine and hydrocortisone, the hyperpigmentation resolved and the hyperpigmented nevi decreased in number.