Hives (Urticaria): Causes

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 the hives:

• Allergic reaction to certain types of food, such as milk, egg, wheat, soy, peanut, tree nuts, fish and shellfish.

• Allergic reaction to certain types of medications such as penicillin and other antibiotics, aspirin, and sulfa drugs.

• Allergic reaction to insect stings from bees, wasps, yellow jackets or fire-ants.

• Eating a particular food and then exercising can cause exercise-induced hives.

• Allergic reactions due to items through occupational contact such as cow dander, natural rubber latex, flour, grains, feeds, enzymes, and a variety of plant and animal species and physical factors such as stress, trauma, pressure, friction, and vibration.

• Underlying diseases, such as thyroid disease, hepatitis, lupus (systemic lupus erythematosus) or some types of cancer; although this is much less common.
• Environmental and behavioral factors such as stress, exercise, sun, heat or alcohol can make hives worse.

This information has been approved by Rohit Katial, MD (March 2009).