Lichen Myxedematosus: Case Report and Review of Literature.

Lichen myxedematosus (LM) is an idiopathic cutaneous mucinosis, commonly described as localized scleromyxedema. In contrast to scleromyxedema, there is typically no systemic involvement. Treatment options are limited and spontaneous resolution has been reported. We present the case of a 66-year-old Hispanic male referred by his primary care physician for evaluation of asymptomatic dark spots on his trunk and extremities present for about one-year. Physical exam revealed smooth, brown hyperpigmented papules coalescing into plaques on the trunk. Multiple well-demarcated oval dark brown plaques measuring 3 cm in size were located on the upper back, peri-umbilical area, bilateral lower extremities, and buttocks. A diagnosis of lichen myxedematosus was made based on histologic features observed in the dermis. There are 5 subtypes of LM: a discrete papular form, acral persistent papular mucinosis, self-healing papular mucinosis, papular mucinosis of infancy, and a pure nodular form. Occasional patients with LM have atypical features or features intermediate between scleromyxedema and localized LM. We present a case of atypical LM with mixed features of the different subtypes. Herein we will review the varied clinical presentations of LM and highlight the distinguishing features of scleromyxedema. J Drugs Dermatol. 2020;19(3): 320-322 doi:10.36849/JDD.2020.4864.