Final answer:
Eosinophils are white blood cells that counteract inflammation by releasing antihistamines, combat parasitic worms, and play a role in allergic reactions such as eczema. Elevated eosinophil counts can indicate allergies or parasitic infections, whereas low counts may point to drug toxicity or stress.
Step-by-step explanation:
Eosinophils are a type of white blood cell that play an important role in the body's immune response. These granulocytes contain granules that stain with eosin and are capable of phagocytosis, meaning they can engulf and digest cellular debris and pathogens. Eosinophils release antihistamine molecules found within their granules to counteract the inflammatory effects of histamines produced by basophils and mast cells.
They are particularly active against parasitic worms and release molecules toxic to these parasites. Eosinophils also release chemical mediators that contribute to late-phase symptoms in allergic reactions, such as eczema, which is characterized by dry, itchy patches of skin. High eosinophil counts can be indicative of allergies, parasitic infections, and certain autoimmune diseases, while low counts may suggest drug toxicity or stress.