A 42-year-old man presented with a 3 month history of erythema and thi
ckening of the forehead skin. He had been diagnosed as hypothyroid 10
years previously and treated with thyroxine at adequate dosage, accord
ing to thyroid function tests. Histology confirmed a myxoedematous inf
iltrate. The forehead is an unusual site for deposition of mucin and t
he late appearance, 10 years after treatment, is also uncharacteristic
. Myxoedema in the usual pretibial site is a feature of Graves' diseas
e. This man, however, had been hypothyroid with no features of Graves'
disease suggesting that there are additional factors other than thyro
id status and thyroid autoimmune disease which may be important in the
development of myxoedematous infiltrates.