Cutaneous mucinosis of infancy: report of a rare case and review of the literature.

Cutaneous mucinosis of infancy (CMI) is a rare dermatologic condition, first reported in 1980 and currently classified within the complex group of papular mucinoses. We report a case of CMI and review the prior 13 cases in the literature. The patient was a 5-year-old girl who presented with asymptomatic dermal papules and plaques on her leg and back with no overlying color change. These lesions were first noticed during infancy and had become slightly more evident over time. The patient had a history of birthmarks and eczema. Her family history included eczema, allergies, photosensitivity, and Graves disease. Pre-biopsy clinical differential diagnosis included connective tissue nevus, granuloma annulare, myofibroma, lipofibroma, and lymphangioma. Biopsies revealed significant increase in interstitial mucin within the reticular and mid dermis, without significant sclerosis or fibroblastic proliferation. The relatively quiescent pattern of interstitial mucinosis with slight fibrocyte hyperplasia presenting as dermal papules-plaques on the trunk and extremities was most consistent with a diagnosis of CMI. We report another case of CMI in an otherwise healthy patient. Our patient is unique as she is the first CMI patient with a family history of Graves disease, although our patient appeared euthyroid. We will also review the literature on this rare entity.