女,35岁,高热、咽痛3天,2周前诊断为甲亢,持续口服甲巯咪唑。查体:咽部红肿,扁桃体2度肿大,双肺呼吸音粗,律齐,腹部未见明显异常。血常规:WBC1.0x109/L,N0.35,Hb120g/L,Ret170,错误的处理是