幼儿急疹也是病毒感染引起，表现多发生在1岁左右，反复发热34天，热退后出疹。血常规白细胞正常或偏低。
B-Symptom I-Symptom I-Symptom I-Symptom O O B-Symptom I-Symptom I-Symptom I-Symptom O O O O O O O O O O O O O O O O B-Symptom I-Symptom O O O O O O O O O O B-Medical_Examination I-Medical_Examination I-Medical_Examination B-Medical_Examination I-Medical_Examination I-Medical_Examination O O O O O O