most common cause of hives in children
Causes of Widespread Hives. 1  Viral Infection. The most common cause of hives all over the body is viral infections. 2  Bacterial Infection. Some bacterial infections can also cause hives. 3  Drug Reaction. An example is a penicillin rash.  Food Reaction. May be an allergy or a 1  coincidence. Bee Sting.