Also referred to as chronic hives, chronic urticaria is diagnosed when a case of hives lasts more than six weeks or recurs frequently. Hives are patches of itchy red or white bumps or welts that appear on the skin. Although the exact cause of chronic urticaria often remains unknown, it is occasionally caused by an allergic reaction to foods or food additives. In this case, a chronic urticaria diet can help relieve the severity or frequency of the condition.
If you haven't been able to pinpoint the exact cause of your chronic urticaria, you might need to begin an elimination diet. To begin an elimination diet, remove all potential food allergens from your diet. Then, reintroduce foods -- one at a time -- about every five days. Throughout the process, keep a food journal to log the types and amounts of foods you eat, along with any symptoms you experience. Since you are introducing foods one at a time, you should be able to identify any that trigger your chronic urticaria symptoms. Your physician can help you determine which foods you should eliminate. Typical food groups eliminated from the diet include dairy products, eggs, citrus fruits, foods made with corn, foods that contain gluten and processed foods.
Certain foods contain histamine, a protein heavily involved in allergic reactions. When histamine is released in the body, it causes blood vessels to become more permeable. As a result, fluids rush into the area and cause swelling. Histamine also triggers smooth muscle to contract, which can be quite dangerous when it affects the muscles surrounding the airways. Since histamine plays such a significant role in allergic reactions, your physician might recommend avoiding histamine-containing foods to lessen the severity of your chronic urticaria. On the histamine-restricted diet, foods to avoid include cheese, yogurt, buttermilk, shellfish, fish, eggs, chocolate, aged foods, fermented foods, artificial food colorings, processed meats and many types of fruits and vegetables.
People with chronic urticaria are often quite sensitive to salicylates, a substance present in aspirin and certain foods, according to the International Chronic Urticaria Society. If your doctor recommends a salicylate-restricted diet, avoid most plant-based foods. This includes nearly all fruits except apples, pears and mangoes that are peeled and cored. Although most vegetables are quite low in salicylates, peeling and cooking them before consumption can be beneficial if you have chronic urticaria. Additional foods to avoid include almonds, peanuts, water chestnuts, artificial colors and artificial flavorings.
Even if your condition does not require you to follow a specific urticaria diet, avoid any foods that trigger a urticaria episode or worsen your symptoms. These food triggers can vary from one person to the next – and an elimination diet can help you to initially determine which foods you need to avoid.