Urticaria is the medical term for hives. Hives are raised, itchy red patches that appear when your body releases a chemical known as histamine in response to an allergen. Foods like shellfish, fish, peanuts, tree nuts, eggs and milk are frequent histamine triggers as are medications like penicillin, aspirin, ibuprophen, naproxen and some blood pressure medications. Other substances that can lead to urticaria include pollen, animal dander, latex and insect stings. Your body mistakes these common substances as threats and produces allergy antibodies to combat them, releasing the histamine that causes inflammation and hives. Each individual hive lasts no longer than 24 hours but in acute Urticaria, hives can be present for a few hours or as long as six weeks. Chronic urticaria lasts for more than six weeks. Whether you are suffering from an acute episode of hives or if you have hives which last for a long time, the welts are made worse by scratching.
Some of the triggers are obvious. If a person eats strawberries or shrimp, then develops urticaria within a short time, then the strawberries or shrimp are the trigger. However, since there are so many possible causes for urticaria, other cases require determined detective work on the part of your Allergist. Your Allergist will take a detailed history for clues in your lifestyle that will help pinpoint the cause of your symptoms. You will be asked about frequency and severity of our symptoms, family medical history, medications you are on, your work and home environment and other information. Your Allergist may require skin testing to be done in the office and/or labs to be drawn at a medical facility.
There are two types of urticaria.
Immunologic or allergic urticaria is the least common form of urticaria. It is caused when the body’s immune system overreacts to an allergen. Recent studies also suggest that some cases of chronic urticaria are caused by autoimmune mechanisms, when the patient develops immune reactions to components of his/her skin.
Non-immunologic urticaria is much more common and seen in cases where a clear cut allergic basis cannot be proven. Some types of non-immunologic urticaria are:
Some cases of non-immunologic urticaria may be caused by non-allergic reactions to aspirin and possibly, certain food dyes, sulfites and other food additives. In many cases, particularly in chronic urticaria, the trigger for the problem cannot be found and thus is called idiopathic urticaria.
Your Allergist can help to alleviate the discomfort of urticaria with over the counter and prescription medications. Severe attacks may be temporarily relieved by injections of epinephrine or the use of corticosteroids. Other drugs may be required for specific types of urticaria.
If the cause can be identified the best treatment is avoidance of the substance. If a problem with a specific food is strongly suspected, then that food should be avoided. This may require a careful reading of food labels and inquiry about ingredient in restaurants. Persons with solar urticaria should wear protective clothing and apply sunscreen lotions when outdoors. Loose-fitting clothing will help relieve pressure urticaria. Avoid harsh soaps and frequent bathing to reduce the problem of dry skin, which can cause itching and scratching that will aggravate it. Vigorous toweling after a bath may precipitate hives.
Although success in identifying the cause of chronic urticaria varies, usually in no more than 20 percent of cases can your Allergist make a determination regarding the cause for the disorder. An outbreak of hives may last for months or for years and burn itself out, never to bother the sufferer again. If you have any more questions about Urticaria your Allergist will be happy to answer them for you.
If you have questions about Urticaria, feel free to contact our offices. One of our staff would be happy to answer your questions and discuss different treatment options offered at Allergy & Asthma Clinics of Ohio.