In myxedema, yellowish tint of the skin is due to:

Myxedema develops in a person who has almost total lack of thyroid hormone function. The patient shows - bagginess under the eye & swelling on the face. In this condition, for reason that are not explained, greatly increased quantities of hyaluronic acid and chondroitin sulphate bond with protein form excessive tissue gel in the interstitial spaces, which causes the total quantity of interstitial fluid to increase. Thyroid hormone is needed for conversion of carotene to vitamin A in skin. In myxedema (decrease T3) this conversion is hampered, therefore increased accumulation of carotene in skin l/t yellowish tint of the skin.