what causes random hives
What causes hives? An allergic reaction can trigger hives. Things that commonly trigger an allergic reaction include: Foods: Fruits (especially citrus fruits), milk, eggs, peanuts, tree nuts, and shellfish. Medicines. Insect bites and stings. Animals. Pollen. Touching something to which you are allergic, such as latex. Allergy shots. Other causes of hives are: Infections, including colds and infections caused by some bacteria or fungi. Some illnesses, including a type of vasculitis, lupus, and thyroid disease.