wide variety of substances may
cause hives in sensitive people, including foods, drugs, and insect bites or stings. Common culprits include:
nuts, especially peanuts, walnuts, and Brazil nuts
fish, mollusks, and shellfish
eggs
wheat
milk
strawberries
food additives and preservatives
penicillin or other antibiotics
flu vaccines
bee, wasp, and hornet stings
bites of mosquitoes, fleas, and scabies.
Urticaria is characterized by redness, swelling, and itching of small areas of the skin.