[Skin and hair, marker organs for thyroid diseases]

Skin and cutaneous appendages are target organs for thyroid hormones. Thus, a variety of changes of skin, hair and nails occurs in association with thyroid diseases. Most of these cutaneous changes are unspecific, but in their entirety they may nontheless be indicative of thyroid diseases. In this review the specific cutaneous lesions as thyroglossal duct cysts and cutaneous metastases of thyroid carcinoma, the unspecific cutaneous changes of hypo- respectively hyperthyroidism, the typical skin lesions of Grave's disease, and selected skin diseases and syndromes associated with thyroid abnormalities are discussed.