Common (and not so common) triggers for hives
Tooth decay and infections of the sinuses, adenoids, tonsils, genitourinary tract, gall bladder and kidney can trigger hives, according to a study published in the journal Advances in Dermatology and Allergology. If you have chronic hives, it is probably a good idea to see your dentist on a regular basis.
Bacterial and viral infections
Strep throat and urinary tract infections have been associated with chronic hives. The American College of Allergy, Asthma and Immunology lists bacterial infections, such as urinary tract infections and strep throat and viral infections, including the common cold, as common triggers for hives.
Sweating may trigger hives in some people. Sweating causes your body temperature to rise, which in turn can trigger hives, according to the American College of Allergy, Asthma and Immunology. If this is one of your triggers, talk to your doctor about taking a non-sedating antihistamine before exercising or being out in the heat.
Food additives, preservatives and coloring
For some people, food additives, preservatives and coloring could trigger an outbreak of hives. A study published in the Indian Journal of Dermatology found that food intolerances might play a role in outbreaks. An elimination diet could help determine if food additives are causing your hives.
Problems with the immune system
About one-half of all cases of chronic idiopathic hives are attributed to the immune system, according to the American College of Allergy, Asthma and Immunology. The most common autoimmune disorders that cause chronic hives are Hashimoto’s disease and hypothyroidism.
Pressure on the skin
Tight waistbands, belts or constrictive clothing can all trigger hives, according to the American College of Allergy, Asthma and Immunology. This can sometimes result in delayed pressure urticaria, where swelling can occur anywhere from six to eight hours after pressure has been applied to the skin.
Insect bites and skin reactions to certain plants
Insect bites and other skin trauma, such as rashes from poison oak or poison ivy, can trigger hives, according to the American College of Allergy, Asthma and Immunology.