Thyroid disease :

Hypothyroidism may cause dry firm gelatinous (myxoedematous) skin with diffuse hair thinning and a loss of the outer third of the eyebrows. Hyperthyroidism may be associated with warm sweaty skin and a diffuse alopecia. Graves' disease is rarely associated with thyroid acropachy ('clubbing' with underlying bone changes) and pretibial myxoedema (a red-brown mucinous infiltration of the shins which can become lumpy and tender).