The term localised myxoedema is preferred to that of ΓÇÿpretibial myxoedemaΓÇÖ since the condition may affect other parts of the body, depending on local pressure or trauma. It may occur in several forms: a nodular form, mimicking erythema nodosum (which differs by being tender to the touch); a sheet-like form with largely nonpitting oedema, coarse thickening of the skin, a red-violaceous discoloration, and coarse hairs; and a horny form with gross overgrowth of skin and subcutaneous tissue on the dorsum of the feet and toes (Fig. 17.41).
The affected areas are densely infiltrated by a hyaline mucopolysaccharide material. Very high circulating levels of TSH-R antibodies are usually present in patients with localised myxoedema.