Pretibial Myxedema in Hypothyroidism – A Clinical Paradox

Abstract

Pretibial myxedema, also known as localized myxedema, is an infiltrative dermopathy. It most often presents as asymptomatic, bilateral diffuse nonpitting edema in the pretibial area. Pretibial myxedema is nearly always associated with Graves’ disease. It is seen approximately in 4% of patients with Graves’ thyrotoxicosis and usually follows ophthalmopathy. Rarely it has been reported in Hashimoto’s thyroiditis and euthyroid patients. Pretibial myxedema may undergo partial or complete remission and is primarily a cosmetic concern. Apart from treatment of the primary thyroid abnormality, topical or intralesional steroids remain the mainstay of treatment. We report a case of a 64 year old man who presented with asymptomatic indurated plaques on both legs. His thyroid function tests were suggestive of primary idiopathic hypothyroidism. Histopathology of the lesion was consistent with pretibial myxedema. A paradox of pretibial myxedema in a patient with primary idiopathic hypothyroidism is a clinical rarity.