There are a variety of foods that naturally contain histamine. These include fermented alcoholic beverages, fermented foods, vinegar-containing foods, cured meats, lunch meats and hot dogs, soured foods, dried fruit, citrus fruit, aged cheese, nuts, nightshade vegetables, and smoked fish.

Certain foods cause the release of histamine that's already present in the body. These include alcohol, bananas, chocolate, cow's milk, nuts, papaya, pineapple, shellfish, strawberries, tomatoes, wheat germ, and many artificial preservatives.

Diamine oxidase (DAO) is the main enzyme responsible for breaking down ingested histamine. So if you’re deficient in DAO, you likely have symptoms of histamine intolerance. Here are some DAO-blocking foods: alcohol, energy drinks, black tea, mate tea, and green tea.

Nonsedating anti-H1 antihistamines remain the mainstay of treatment for chronic hives (urticaria). If these medications are ineffective, higher dosages may be tried, or others may be substituted

You might be wondering what exactly you _can _eat! Fear not! There are plenty of delicious foods you still can eat, including fresh meat, fresh fish, gluten-free grains, fresh fruit, fresh veggies, dairy substitutes, eggs, and herbal teas.

Overheating and the pressure of belts and tight clothing aggravate chronic hives, so try wearing loose, comfortable clothes.

Aspirin is the most common drug to aggravate urticaria. Aspirin and other NSAIDs can worsen chronic hives in 20 to 30 percent of patients during an active phase, but probably not in remission.

If you suffer from chronic idiopathic urticaria, and other treatment options aren't working, you may want to speak to your doctor about omalizumab. Omalizumab is biologic medication administered via injection and is approved for people 12 years of age and older who remain symptomatic despite treatment with H1-antihistamine therapy.