Triade de Diamond: une manifestation exceptionnelle de la maladie de Basedow

Extra-ocular manifestations of Graves´ disease are rare and little known. We here report one of its manifestations: Diamond´s triad is defined as the association of exophthalmos, acropachy (<1%) and pretibial myxedema (1.5-2%). It has been rarely found in patients with Graves´ disease. We here report the case of a 33-year-old patient with no particular previous history, on follow-up for Graves´ disease, complicated by cardiac arrhythmia (atrial fibrillation), treated with synthetic antithyroid drugs followed by total thyroidectomy after cardiac and thyroid stabilization. The patient reported purplish lesions on the anterior face of the legs that had persisted for several years. Clinical examination showed voluminous vascular goiter and vitiligo lesions, associated with bilateral exophthalmos, with Clinical Activity Score < 3 (A) (amended by European Group on Graves' orbitopathy (EUGOGO)), discrete pretibial oedema with purple erythematous patches, painless and firm to palpation, on the anterior face of the legs (B) and pretibial myxedema suggesting pretibial dermopathy (Basedow´s disease). The fingers and toes are clubbed in the shape of a drumstick (digital hippocratism) (C, D), suggesting dysthyroid acropathy. Dysthyroid acropathy occurs in less than 1% of patients with Graves´ disease but is constantly associated with exophthalmos and pretibial myxedema, thus forming the Diamond Triad, as in the case of our patient.