Could a low-histamine diet help you ease skin symptoms from chronic spontaneous urticaria (CSU), or hives? New research suggests that avoiding high-histamine foods can help you clear up this nagging, itchy, blotchy skin condition.
What Is Chronic Spontaneous Urticaria?
Chronic spontaneous urticaria (CSU), also called hives, is when large areas of your skin break out in welts: red or skin-colored, usually very itchy, burning, circular, raised blotches. You may also have angioedema, or swelling that affects deeper layers of your skin.
Hives can appear anywhere on your body. Angioedema may cause your eyelids, lips, tongue, hands, and/or feet to swell.
Chronic hives come back again and again. And when they do, they usually stick around for a while. Welts appear on most days of the week. Flares may last for 6 weeks or longer, but some people have hives for months or years. This can have a negative effect on your emotions, quality of life, and self-image.
No Known Triggers
CSU is also spontaneous. That means we don’t know exactly what triggers these hives.
Treatments for CSU include medications, like non-drowsy antihistamines, immunomodulators, or steroids, as well as phototherapy (ultraviolet light treatments on the skin).
Is a low-histamine diet another way to manage or prevent your hives? Some people think it helps.
CSU and Histamines: What’s the Connection?
What we do know: Hives happen when mast cells – a type of white blood cell – in your skin become activated for some reason. They release a chemical called histamine that spreads through your skin tissue and irritates nerves. That’s why your hives itch so badly.
Histamine also makes very small vessels in your skin widen and leak blood. That’s why hives on your skin look red, blotchy, and swollen.
Your body may send a signal to your skin mast cells to release histamine when it senses something wrong. For some people, eating foods rich in histamines may set off this chemical release. Some people with CSU may not be able to break down histamines in foods as they digest them, causing hives.
About 1% of people, most often in middle age, have strong physical reactions to histamines in foods. They not only break out in hives, but may also have other severe symptoms:
- Belly pain, diarrhea, or flatulence (passing gas)
- Watery eyes
- Rapid heartbeat
- Low blood pressure
Does a Low-Histamine Diet Clear Up Hives?
Because of the histamine-hives connection, could eating low-histamine foods and avoiding high-histamine foods prevent or treat urticaria? Here’s some evidence that it does:
- In one study from 2016, 56 people with CSU followed a low-histamine diet for 3 weeks, and 75% had significantly reduced symptoms. They also reported that their quality of life improved when they followed the low-histamine eating plan.
- In a study from 2018, 22 adults with chronic hives followed a low-histamine diet for 4 weeks. Their hives improved and they slept better, even though they still took the same number of antihistamine or steroid pills each day as they did before they started the diet.
You may still need to take antihistamines to treat other symptoms, like skin flushing, nausea, or stomach upset, even if a low-histamine diet seems to reduce your hives.
While there’s other research that shows a low-histamine diet can partially or totally clear chronic hives in some people, CSU symptoms sometimes go away on their own or with antihistamines.
Your doctor may consider other possible causes for your hives:
Other medicines you take. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin, and isoniazid/doxycycline for acne, can interfere with how your body breaks down histamines in foods. If you take these medicines, foods you eat may release more histamine and trigger hives.
Low vitamin D levels. There’s some evidence that people with CSU may be linked to low levels of vitamin D. In 2018, a large, pooled analysis of 14 studies showed that vitamin D deficiency is much more common in adults, but not children, who get hives. Vitamin D may play a role in both allergies and autoimmune skin diseases, including stopping mast cells from releasing histamine.
Your doctor can test your blood for vitamin D. If your levels are too low, your doctor may suggest a supplement, getting more sun exposure on your skin, or eating vitamin D-rich foods like fortified milk and cereals, fresh salmon or swordfish, or eggs.
Celiac disease. Some people with celiac disease, an autoimmune condition, also have chronic urticaria after they eat gluten found in foods like wheat, barley, or rye. When you have celiac disease, you can’t digest gluten.
Your doctor may test you for celiac disease, or suggest that you avoid gluten in your diet and see if that calms your hives.
What Is a Low-Histamine Diet?
On a low-histamine diet, you try to curb or avoid foods and drinks high in histamines. Here are a few quick tips:
- Some foods are naturally high in histamines, but others only become high-histamine once fermented, preserved, or spoiled.
- Don’t eat smoked, salted, fermented, or marinated foods.
- Fish like tuna or mackerel that’s spoiled can be very high in histamine. If you’re not sure any fish is fresh, throw it out.
Try to avoid these high-histamine foods and beverages:
- Aged cheeses like Parmesan, Emmentaler, and Gorgonzola (blue cheese)
- Processed (luncheon) meats
- Fermented foods or sauces, like soy, sauerkraut, pickles, yogurt, or kimchi
- Canned or smoked fish, especially tuna, sardines, anchovies, and mackerel
- Sausages, hot dogs, salami, and dried or cured ham
- Alcoholic beverages, including beer, red wine, white wine, Champagne or sparkling wine, liquor, and sweet dessert wines
- Red wine vinegar
- Soy sauce
- Spices like chili powder, cinnamon, and cloves
- Black tea
- Fermented sauces like ketchup, red pepper paste, soybean paste, and mayonnaise
Low-histamine food and drinks:
Take these steps to lower histamine in your diet:
- Eat fresh, whole, or unprocessed foods when possible. Even removing a natural rind or peel can raise histamine content in a fruit or vegetable.
- Fish may be kept on ice at supermarkets for days, so it may not be fresh when you buy it. Ask for the freshest fish.
- Drink plenty of fresh water or soda water.
Enjoy these low-histamine foods:
- Dairy products like pasteurized whole, low-fat, or skim milk, buttermilk, cream, sour cream, farmer’s cheese, and cream cheese
- Fresh beef, chicken, pork, veal, or lamb, or meats frozen while fresh, not smoked or aged
- Fresh fish and shellfish, or seafood that’s frozen while fresh
- Fresh or frozen fruits
- Homemade fruit or vegetable juice
- Fresh or frozen vegetables, except avocados, eggplant, tomatoes, and spinach
- Whole grains, bread, cereal, and rice
- Butter or margarine
Testing Your Histamine Intolerance
Talk to your doctor before you start tossing out every high-histamine food in your fridge. When you cut out large groups of foods from your diet, you may not get a variety of nutrients that you need for good health. This is especially risky for children, who need a nutrient-rich diet to fuel healthy growth.
Your doctor or allergist will ask you about your medical history and give you a physical exam. They’ll ask you about your CSU symptoms and possible triggers, including foods.
Lab tests. There’s no specific test to prove that you’re sensitive to histamines. You may just notice that your hives flare up after you have certain foods or drinks. There is one blood test to check for antibodies seen in chronic urticaria, but it’s not widely available.
Your doctor may order one or more of these lab tests:
- Complete blood count (CBC) test to check for signs of inflammation
- Skin prick test to see if you’re sensitive to any ingredients or foods
- Thyroid function tests, which can show if you’re low in thyroid hormone. If you have a sluggish thyroid, antihistamines or steroids you take to relieve your hives won’t work as well. You may need to take a thyroid hormone replacement pill.
- If you also have GI symptoms, like stomach upset or diarrhea, along with hives, your doctor can test a sample of your stool for signs of a parasite infection.
Based on your exam and test results, your doctor may suggest a low-histamine diet and give you a list of foods to avoid.
Here are other ways to help you manage CSU through your diet:
Keep a food diary. Track everything you eat or drink in a food diary, journal, calendar, or smartphone app. This helps you and your doctor narrow down any specific foods or ingredients that trigger hives from CSU.
Meet with a registered dietitian (RD). A registered dietitian can give you some low-histamine meal and snack ideas to help you get started, and make sure you still get the nutrients you need from the food you eat.
Photo Credit: photo_chaz / Getty Images
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