Pre tibial myxedema associated with hypothyroid Hashimioto’s thyroiditis

Abstract

Pretibial myxedema (PTM) is an infiltrative dermopathy due to accumulation of glycosaminoglycans in the dermis and sub cutis. It is commonly associated with Grave’s disease. However, it is infrequently associated with Hashimoto’s thyroiditis and primary hypothyroidism. It often presents as an asymptomatic diffuse non pitting edema, nodule or plaque involving both pretibial areas. Pretibial myxedema may undergo partial or complete remission and is primarily a cosmetic concern for the patient. Apart from treatment of the primary thyroid abnormality, topical or intralesional steroids remain the mainstay of treatment. We report a case of a 72-year-old lady who presented with non pitting edema on both legs. Her thyroid function tests were suggestive of hypothyroidism and thyroid auto antibody profile, ultrasonography and fine needle aspiration cytology favored Hashimoto’s thyroiditis. Histopathology of the pretibial skin was in consistent with pretibial myxedema. A paradox of pretibial myxedema in a patient with Hashimoto’s thyroiditis is a rare clinical entity.