LISTEN TO ME, NOT MY THYROID. E. Chan 1 , J. Wiese 1 ; 1 Tulane University, New Orleans, LA (Tracking ID #77077) LEARNING OBJECTIVES: 1. Listen to the patient's previous history to establish appropriate management decisions. 2. Use the history of the patient's symptoms to distinguish Graves disease from propylthiouracil allergy. CASE INFORMATION: A 23 year-old woman presented with recurrent palpitations, muscle weakness and dyspnea. She had a past history of Graves disease but had refused propylthiouracil therapy. She had a heart rate of 130, and a temperature of 104 F. There was right eye exophthalmos, a diffusely enlarged thyroid. A venous hum was heard over the thyroid; she had proximal muscle weakness and hyperreflexia. The thyrotropin levelwas 0.06U/ ml and the FT4 was 17.01 g/dl. She was treated with with potassium iodide, propylthiouracil and propranolol with resoluton of her symptoms. Three days later, she developed severe generalized arthralgias and myalgias with progressively deteriorating muscle strength and swelling of her fingers. Her anti-nuclear antibody, anti-histone antibody, and acetylcholine receptor antibody were negative. The anti-striated muscle antibody, rheumatoid factor and p-ANCA were also negative. The propylthiouracil was discontinued based upon the hypothesis that the new symptoms were due to an allergic response, Her symptoms resolved the following day. Upon further questioning, she noted a similar reaction to a previous treatement with propythiouracil as the cause of her non-compliance with this therap. A subtotal thyroidectomy, resulted in complete resolution of her symptoms. IMPLICATIONS/DISCUSSION: The appropriate management decision is often obtained by listening to the patient. In the thrill of treating Graves's disease, the reason for the patient's previous non-compliance with propylthiouracil was ignored. Although an allergic reaction to propylthiouracil is rare, it is characterized by arthralgias, myalgias, anxiety and tachycardia when it occurs. Distinguishing this reaction from continued symptoms of Graves's disease requires a meticulous history. Thyroidectomy is the treatment of choice in patients who are unable to tolerate propylthiouracil therapy. Carefully listening to why patients have declined previous therapy is important in preventing recurrence of previous adverse effects.