Question
A four-year-old girl has undergone a blood test in the past, which showed that her white blood cells were normal, but the percentage of neutrophils was always below 20%, while the ratio of lymphocytes was between 70-80%, and platelets remained at a normal level. When she has upper respiratory infections, her throat becomes red and swollen, and the lymph nodes under her chin also swell. Two years ago, she had a mycoplasma infection, which was cured through the administration of erythromycin. After the Spring Festival of 2009, she experienced two upper respiratory infections within less than a week, during which she was treated with cephalosporin antibiotics and antiviral drugs (including intravenous infusions), and also took oral erythromycin. She also used antipyretic drugs when she had a fever. Her blood test showed that her white blood cell count was below 3, with neutrophils at 6.6%, lymphocytes at 80%, and platelets at 85. The mycoplasma antibody test result was 1:320, and she had ulcers in her mouth.