Pretibial Myxedema in a Hypothyroid Patient with Grave’s Disease: A Case Report

Abstract

Pretibial myxedema, a rare dermatological manifestation primarily associated with Graves' disease, presents as nonpitting edema, nodular, or plaque-like lesions on the lower legs due to accumulation of hyaluronic acid. We present the case of a 42-year-old woman with a history of Graves' disease who developed dark plaques and indurated skin lesions on her shins, extending to the dorsal feet. Diagnosed with Grave’s disease 20 years prior, she underwent subtotal thyroidectomy following antithyroid treatment. Pretibial myxedema developed one-year post-thyroidectomy and was managed with systemic glucocorticoids. She later received iodine-131 therapy, which led to hypothyroidism, and started to admit thyroid hormone replacement. The thyroid function test revealed normal TSH levels and increased TRAbs. Histopathology of skin lesions showed mucopolysaccharide deposition and increased collagen confirming myxedema. This case highlights the rare elephantiasis form of pretibial myxedema and underscores the importance of recognizing characteristic skin lesions in patients with hypothyroidism.