A healthy 1-year-old child comes to your office for a routine checkup and for immunizations. His parents have no complaints or concerns. The next day, the CBC you performed as customary screening for anemia returns with the percentage of eosinophils on the differential to be 30%. Which of the following is the most likely explanation?
a) Allergic reaction to immunizations
b) Parasitic infection
c) Normal variation in eosinophil count
d) Eosinophilic esophagitis