Allergies are caused by the body's overzealous reaction to normally harmless substances. Allergies can be triggered by pollen, animal dander, mold, dust, and insect droppings, or by certain foods or insect stings. Upper respiratory allergy symptoms include runny nose, itchy eyes, coughing, wheezing, and sneezing.

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College Student in Ohio Suffers Fatal Allergic Reaction to Milk Product

The 20-year-old was found dead holding his EpiPen after developing anaphylaxis.