Thyroid Disease and the Skin
Thyroid disease is associated with changes in the skin, which may sometimes be the first clinical sign. A variety of cutaneous findings may present in the setting of either a hyperthyroid or hypothyroid state. There may be evidence of the effect of altered concentrations of thyroxine on the skin, with changes in texture and hair growth. Associated increases in thyroid stimulating hormone concentration may lead to pretibial myxedema. Hair follicles are particularly sensitive to concentrations of thyroid gland derived hormones. The cells of the hair matrix, due to their high degree of metabolic activity, are most profoundly influenced by the deficiency or excess of thyroid derived hormones. There is convincing evidence of a significant association between thyroid autoimmunity and skin disorders. Most commonly reported cutaneous disorders related with thyroid disease are alopecia areata and vitiligo. This review constitutes a summary and update of the cutaneous manifestation of thyroid disease.