Eosinophilia can indicate which conditions?

• A. All of the above
• B. Allergies
• C. Parasitic infection
• D. Cancer

Answer: (A)

Eosinophilia signals an increased eosinophil response, which can arise from several different processes. In allergies, eosinophils are recruited as part of the IgE-mediated inflammatory response, driven by cytokines like IL-5. In parasitic infections, especially helminths, eosinophils play a direct role in defense against the parasite. It can also appear with certain cancers, such as Hodgkin lymphoma or other malignancies, where tumor cells or the surrounding environment produce cytokines that cause eosinophil expansion. Because eosinophilia can be associated with allergic, infectious, and malignant conditions, the finding can indicate all of these. That makes the most inclusive option the best choice.