Topic : Thyrotoxicosis 1. Amiodarone can cause thyrotoxicosis 2. Plummer's nails are seen 3. Pretibial myxoedema is a feature 4. Ferritin is usually elevated 5. Initial investigation is TSH and free T3

Initial investigation in a case of thyrotoxicosis includes estimation of TSH and unbound T4 levels. Amiodarone is associated with thyrotoxicosis without hypehyroidism. Other causes of thyrotoxicosis without hypehyroidism are subacute thyroiditis, silent thyroiditis and factitious thyrotoxicosis. Skin manifestations of hypehyroidism are 10Ps such as : Pretibial myxedema, Palmar erythema, Periorbital swelling, Persistent facial flush, Poor hair growth, Pink papules and plaques, Pigmentation increased, Propotosis, sweaty Palms and Plummer's nails. Ferritin levels are increased in thyrotoxicosis due to direct stimulation of ferritin synthesis by thyroid hormones.