Certification in Infection Prevention and Control (CIC) Practice Exam

Which of the following is a possible cause of increased eosinophil count?

1. Viral infection

2. Allergic reactions

3. Bacterial infection

4. Chronic illness

The correct answer is: Allergic reactions

An increased eosinophil count, known as eosinophilia, is commonly associated with allergic reactions. Eosinophils are a type of white blood cell that play a critical role in the body's immune response, particularly in responding to allergens, parasites, and certain infections. When the immune system encounters an allergen, such as pollen, pet dander, or certain foods, it triggers an inflammatory response that leads to the proliferation and activation of eosinophils. This response is crucial in combating the effects of allergic reactions, which include inflammation and tissue damage. In the case of allergic reactions, eosinophils release mediators that can contribute to the symptoms of allergies, such as asthma, hay fever, and eczema. Their increased presence in the bloodstream is a direct indication of the body’s heightened immune response to these triggers, reflecting the importance of eosinophils in both protecting the body and in pathophysiological processes associated with allergies. Other options like viral infections, bacterial infections, and chronic illness typically do not lead to a significant increase in eosinophils. Viral infections often result in a lymphocytic response, bacterial infections generally cause neutrophilia, and chronic illnesses may cause a variety of immune responses but do