Urticaria (hives) is often an incredibly frustrating condition. When the hives keep occurring for more than six weeks, as yours have, doctors call that chronic urticaria. The cause of chronic urticaria is found in a small percent of patients.
Urticaria is an allergic reaction. When doctors cannot identify the underlying cause after a thorough diagnostic evaluation, we refer to the condition as idiopathic urticaria.
I suspect you and your doctors have considered the more common causes besides food and environmental allergens. These include:
- Medications, including herbs, supplements, and over-the-counter drugs
- Bug bites, such as scabies and bedbugs
- Physical causes, such as pressure, cold or hot temperatures, and sun exposure
- Exercise, as the skin gets warm and sweaty
You probably have had a lot of blood tests already. Unfortunately, these tests usually dont point to a specific cause. Even a skin biopsy wont provide a specific answer in most cases. But it may we worthwhile to have a skin biopsy to exclude a rare condition called urticarial vasculitis.
Dermatologists now believe that many people given the diagnosis of idiopathic urticaria in the past actually had a form of an autoimmune disorder. For unknown reasons, a persons immune system may be triggered to react against his/her own skin.
Regarding treatment, people with persistent urticaria often need higher than the usual doses of antihistamines. There are many to choose from. You may need to try a few combinations of antihistamines. The antidepressant doxepin has potent antihistamine properties. It is sometimes very effective when more traditional antihistamines have not controlled the hives.
Corticosteroids such as prednisone may be needed in severe cases. Because of side effects, doctors try to use the smallest dose for the shortest time.
The good news is that most often the hives do stop, but how long yours will persist cannot be predicted. Dont give up. Keep working with your doctors to find the best control of your hives until they stop.