In which scenario would increased eosinophil levels be expected?

Increased eosinophil levels are primarily associated with allergic responses and parasitic infections. Eosinophils are a type of white blood cell that plays a crucial role in the immune system, particularly in combating larger parasites and mediating allergic reactions. When the body encounters allergens, such as pollen, dust mites, or pet dander, or when it faces parasitic infections like those caused by helminths (worms), eosinophils respond by increasing in number to help mitigate the potential threat. Their activation leads to symptoms commonly associated with allergies, such as asthma and hay fever, as well as being part of the body’s defense mechanism against parasites.

This context aligns well with the concept that eosinophils express specific receptors that allow them to migrate to sites of inflammation and respond to the signals released during these immune challenges. This is why, in scenarios involving allergic reactions or parasitic infections, a notable increase in eosinophil levels is observed, indicating their role in these pathological processes.