Since hives (urticaria) can be caused by lots of different things, or in some cases a combination of things, it is often challenging to pin down an exact cause. However, the following may be contributing to hives:
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Allergic reaction to certain types of food, such as milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish.
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Allergic reaction to certain types of medications, such as penicillin and other antibiotics, aspirin, and sulfa drugs.
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Allergic reaction to insect stings from bees, wasps, yellow jackets or fire ants.
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Eating a particular food and then exercising can cause food-dependent, exercise-induced hives.
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Allergic reactions to items through occupational contact such as cow dander, natural rubber latex, flour, grains, feeds, enzymes, and a variety of plant and animal species.
- Physical, environmental, and behavioral factors such as stress, trauma, pressure, friction, heat, cold, water, sunlight, exercise, alcohol, and vibration.
- Underlying diseases such as thyroid disease, hepatitis, lupus (systemic lupus erythematosus) or some types of cancer; these are much less common.
