The epidermal response to change in thyroid status

Abstract

Epidermal dimensions, replication, and anabolic activity were studied before and after treatment in 10 patients with thyrotoxicosis and 7 patients with hypothyroidism. Following treatment of thyrotoxicosis there was a significant decrease in epidermal thickness, and also in cell replication as measured by autoradiography. The rates of anabolic activity in the epidermis, as estimated by measuring the rates of incorporation of H3 precursor compounds, were significantly reduced after treatment in the thyrotoxic group. Therr were increases in these same measurements in the hypothyroid group following treatment although their magnitude was not as great as that seen after treatment of thyrotoxicosis. There was a significant positive correlation between serum triiodothyronine and epidermal thickness, labeling index and proline incorporation, but no correlation could be detected between serum thyroxine iodine and any of the epidermal measurements. These findings indicate that the epidermis does change in structure and activity in thyroid disease, and that these changes are rapidly reversible. Furthermore, the correlations found suggest that the receptors for thyroid hormone in human skin are specific for triiodothyronine.