Provided by Megan Goebel, MD
Hives are one of the most common reasons for a visit to an Allergist, with up to a quarter of the population experiencing hives at some point in their life. Hives, or welts, are red or white raised areas on the skin that itch. The itching can interfere with school, work and sleep. There are many causes for hives including allergic reactions to foods, medications, animal dander, insect stings or bites, or pollen. Typically with a food allergy, a patient will develop hives within 30 minutes of eating. This may be accompanied by swelling, throat tightness, trouble breathing, or vomiting which is called anaphylaxis. The most common food allergens are peanuts, tree nuts, fish, shellfish, cow’s milk, eggs, wheat and soy. If your symptoms are suggestive of a food or environmental allergy, your Allergist may perform skin prick testing to help diagnose this. In children, hives often develop during an infection which may occur with fever, runny nose, sore throat, vomiting, diarrhea or burning with urination. These hives will resolve on their own as your immune system fights the infection.
Hives that last longer than six weeks are called chronic urticaria. These hives are less likely to be caused by an allergic reaction and more often are due to your immune system releasing a chemical called histamine, which causes itching and swelling. Physical triggers including heat, cold, pressure, sunlight and sweat. This condition can be treated with high doses of antihistamines and your doctor may order some blood tests to look for other causes.
While itchy and uncomfortable, the good news is that hives are not dangerous on their own and can be treated. Typically a twice daily antihistamine such as cetirizine or fexofenadine will be recommended. A medication called Xolair® has been very successful in treating chronic hives and can be administered as an injection at your Allergist’s office if needed.