Why am I breaking out in hives?
Allergic reactions, chemicals in certain foods, insect stings, sunlight exposure, or medications can all cause histamine release. It's often impossible to find out exactly why hives have formed. … The most common causes are certain foods, medications, or infections.
What foods cause hives?
The most common foods that cause hives are nuts, chocolate, fish, tomatoes, eggs, fresh berries, soy, wheat, and milk. Fresh foods cause hives more often than cooked foods. Certain food additives and preservatives may also be to blame.