女,76岁。因全身瘙痒、皮疹5日于1997-08-23入院。入院前5日因低热、咳嗽,来我院门诊就医。当时查血常规:血红蛋白105g/L,白细胞11.4×109/L,中性粒细胞0.72,淋巴细胞0.18,其它0.10,血小板117×109/L。诊断上呼吸道感染。予头孢氨苄0.25g,1日4次口服。服药第3日后双下肢皮肤出 Female, 76 years old. Due to systemic itching, rash 5 in 1997-08-23 admission. 5 days before admission for fever, cough, to our hospital for medical treatment. At that time check the blood routine: hemoglobin 105g / L, white blood cells 11.4 × 109 / L, neutrophils 0.72, lymphocytes 0.18, other 0.10, platelets 117 × 109 / L. Diagnosis of upper respiratory tract infection. To cephalexin 0.25g, 4 times on the 1st orally. After the third day of medication lower extremity skin