A man with indurated plaques and non-pitting oedema on the shins

A man in his 30s presented with an 18 month history of indurated plaques and diffuse non-pitting oedema on the shins. The plaques were not painful or itchy and some were coloured purple-brown. The patient had previously been told that the lesions were possibly lymphoedema but did not receive treatment. He reported a weight loss of 8 kg during this period, an increased appetite, palpitations, tremors, heat intolerance, and excessive sweating. The patient did not report any gritty sensation in the eyes, photophobia, tearing, diplopia, or increased bowel movements. The patient had a history of hypertension and was taking 150 mg irbesartan once daily. There was no relevant family history. On examination, his heart rate was 106/min with a regular rhythm. There was no exophthalmos or lid lag, but fine tremors were noted in the tongue and both hands when held up. Palpation of his neck revealed a grade II diffuse goitre …