TEMPORAL RELATIONSHIP BETWEEN THE ONSET OF THYROID DERMOPATHY AND GRAVES' OPHTHALMOPATHY

Abstract

Pretibial myxedema is an uncommon manifestation of Graves' disease and because of its rarity, information regarding its natural course and its relationship with other manifestations of Graves' disease is not sufficient.
We reviewed 150 consecutive cases diagnosed as having pretibial myxedema in a twenty-year period in a tertiary care center. Only one patient in this group did not have ophthalmopathy, and the majority of cases had significant proptosis and ophthalmopathy, 30% required orbital decompression surgery. Dermopathy is a late manifestation of the Graves' disease and its onset is usually after the diagnosis of hyperthyroidism and ophthalmopathy. In a few patients, dermopathy preceded diagnosis of hyperthyroidism or the onset of ophthalmopathy. Fourteen patients have never had hyperthyroid, eleven patients in this group had developed spontaneous hypothyroidism.
All cases showed the involvement of the lower extremities, and only one patient showed to have combined upper and lower extremities involvement. The most common form of thyroid dermopathy was non-pitting edema. Nodular and plaque forms were also relatively common and occurred with equal frequency. Polypoid form occurred in one patient and elephantiatic form in another. There was no consistent correlation among different types of dermopathy and severity of eye disease.
During a three-month to nineteen-year follow up in 120 patients, complete remission was observed only in twelve patients. Partial remission was more common and occurred more frequently in patients who had local steroid therapy. it is possible that patients with remission might have been excluded of the follow up program.Thus, the remission data should be interpreted cautiously.