Pretibial Myxedema

Zubina Mawji, MD

The persistent effects of Graves disease were evident in a 48-year-old woman who had recently emigrated from Haiti to the United States. Thyrotoxicosis had developed several years before she sought treatment in her native country. The patient's obstructive goiter was removed and treatment with thyroxine was begun.

The persistent effects of Graves disease were evident in a 48-year-old woman who had recently emigrated from Haiti to the United States. Thyrotoxicosis had developed several years before she sought treatment in her native country. The patient's obstructive goiter was removed and treatment with thyroxine was begun.

Dr Zubina M. Mawji of Allentown, Pa, writes that in addition to Graves ophthalmopathy, the patient had a distinctive dermopathy-pretibial myxedema-over the dorsa of her lower legs and feet. The skin featured a peau d'orange texture with pruritus and hyperpigmentation. Skin thickening results from infiltration of the dermis by lymphocytes and hydrophilic, metachromatically staining mucopolysaccharides.

The plaques or nodules of pretibial myxedema are usually discrete; occasionally, the lesions may be confluent. Half of all cases of this dermopathy occur before the onset of hyperthyroidism; the rest occur during active thyrotoxicosis. Pretibial myxedema is the least common of the 3 classic manifestations of Graves disease; hyperthyroidism and ophthalmopathy occur more frequently.

This patient's only complaint was itching of the lower extremities. Topical corticosteroids eased the pruritus. The thyroxine therapy continues.