The Chronic Idiopathic Urticaria Elimination Diet: The Foods to Avoid If You Have Chronic Hives
Updated: Aug 16, 2020
My Own Case of Hives: Miserable
I have personally dealt with hives twice in my life. And both were miserable.
The first time, I was living in Chicago, and I had caught some type of upper respiratory virus. It wasn't awful, but it wasn't comfortable either. I was walking around with a cough and runny nose, and still trying to take care of patients.
What really sent me over the edge, though, was when I woke up the next morning. One entire side of my face was swollen and distorted. And my body was covered in big, red, swollen patches. And to top it all off, each of these patches was incredibly itchy. I had developed hives.
Can Avoiding Certain Foods Help If You're Dealing With Hives?
I remember attending a medical conference for dermatologists and attending a lecture on chronic hives. The speaker presented a really intriguing case. He had been treating a patient who had dealt with hives for YEARS. Red, itchy patches, all over her body, moving every 24 hours, and they just kept coming. She had tried multiple different oral medications, which only partially helped. Finally, she eliminated one thing from her diet, and the hives just stopped.
She stopped chewing pink bubble gum.
In fact, studies have shown that for some people, certain foods act as triggers for hives. One of these categories is food dyes, preservatives, and additives. Other top triggers include alcohol, tomatoes, seafood, fruits and fruit juices, and certain herbs and spices. And other top triggers include other foods such as candy and chewing gum.
Food Allergies Are Rare Causes of Hives, But Food Triggers Are Common And May Worsen Hives
My own case of hives, luckily, went away after about 2 weeks of taking oral antihistamines. Many of the patients I've treated haven't been so lucky, and their hives have gone on for weeks, and sometimes even months.
Which is why I get so many questions about whether foods could be an issue. It's an intriguing question, but one for which I had heard conflicting opinions. This question led me to scour the medical literature and finally publish a review article in a medical journal.
The bottom line? Food allergies are an extremely rare cause of chronic hives. Food triggers, on the other hand, may play a role in worsening hives in about 1 in 3 patients with chronic hives. Food allergies and food triggers have different immune system pathways. But in terms of clinical findings they can sometimes be hard to tell apart.
In this post, I'll review more about the research behind the chronic urticaria elimination diet and why you may want to try it for 3 weeks if you're dealing with chronic hives.
Chronic Idiopathic Urticaria: What Is It, and Why Does It Occur?
The medical term for hives is "urticaria". Hives consist of raised, itchy patches known as "wheals". These wheals may be red or they may be flesh-colored. They can be incredibly itchy, and they are certainly frustrating.
The individual wheals seen in hives, by definition, come and go within 24 hours. However, it’s really common to continue to develop new wheals on other areas, for days or even weeks at a time. In other words, you develop a wheal on your arm, and it goes away 24 hours later. But in the meantime, you develop a new wheal on your leg and later another one on your face. And that cycle may continue for weeks on end. If these outbreaks go on for more than six weeks, we call them chronic. And chronic urticaria is especially frustrating. That's because in many cases, there is no known cause for why these outbreaks are occurring. In medical terms, the hives are "idiopathic". In other words, we don't have an explanation as to why they started or why they keep going. To make it worse, chronic urticaria is unpredictable. For some people, the outbreaks will eventually go away after a few months. For others, the outbreaks may go on for years. And this is where the question of food allergies comes in.
Food Allergies Are A Rare Cause of Hives, But Food "Triggers" May Play a Role in Some People
It may sound surprising, but when we say there is no known cause for most cases of chronic urticaria, we mean it. One of the most common questions I get from patients is this: "What about food allergies?"
The short answer is that food allergies are a very rare cause of hives. There are a few notable exceptions. Specifically, if you have celiac disease (an allergy to gluten confirmed by a blood test), a history of tick bites, or a history of raw fish ingestion in Europe, then you need to check out Table 1 in this article about the specific types of food allergies that have been linked to chronic hives. For everyone else though, we’re not concerned about food allergies as much as potential food triggers.
The Difference Between Food Allergies and Food Triggers
When we talk about food allergies, we're referring to the activation of a very specific immune system pathway. Since your immune system has a memory, this means that every time you eat that food, you trigger the activation of that pathway. And that ultimately results in symptoms.
With food triggers, on the other hand, there's not a particular immune system pathway involved. The reaction may not actually occur every time you eat that food.
Instead, there may be more of a threshold effect. In other words, if you eat enough of a particular food (or group of foods), then you may go over the threshold. In this case, going over the threshold means that you start to develop symptoms.
Many unanswered questions about food triggers
We know that food triggers play a role in some people with chronic hives. But there's a whole lot that we don't know about this type of reaction.
Let's start with what we DO know.
First, from observation, we know that some foods, such as alcohol, seem to trigger a worsening of hives.
Second, we know that for some people, if they eat enough of one type of food, or if they eat a bunch of certain foods at the same meal, they seem to hit a tipping point. Eat enough, and your hives start to get worse.
Third, we know from research studies that if you take a group of patients with chronic hives, and ask them to avoid ALL of these foods for at least 3 weeks, then some of them will start to get better. They'll develop fewer hives every day. Their quality of life will improve. They may require lower doses of antihistamines. And, for a lucky few, their hives may even go away completely.
Which brings up an important question: what do we mean by "some" patients will get better?
In the studies done to date, it is estimated that about 1 in 3 patients will benefit from this type of elimination diet. (Not cured, but better). Unfortunately, at this point in time, we don't have any way to predict which patients may benefit from this type of diet.
Which patients should try this elimination diet?
Would I recommend this approach to every person with hives? Absolutely not. (Even though you have plenty of alternate foods to eat, elimination diets are never fun. And I never recommend any elimination diets to children without a thorough evaluation first.)
I would, however, recommend it for certain patients. Specifically, for patients who are requiring daily doses of antihistamines to help control their hives, it may be worth it to try eliminating these foods for 3 weeks.
And even if you can't eliminate all of these foods, it may be worth it to eliminate a few, especially alcohol, food additives, and tomatoes.
Food Triggers: The Foods to Avoid
These are the general groups of foods to avoid:
Food additives (dyes, preservatives, artificial sweeteners)
Certain herbs and spices
Fruits and fruit juices
Other foods, including candy and chewing gum
Studies of the chronic urticaria diet
There have been closely observed experimental trials of this elimination diet approach. In these studies, patients with chronic hives have been asked to eliminate these foods. During this time, they are asked to keep a diary of how many hives they get daily, as well as how much medication they use. In these trials, about 1 in 3 volunteers have noted improvement.
What is it about these foods that seems to worsen hives?
The short answer to this question is that we don't know. Despite a number of research studies, we don't have a clear answer.
We do know that histamine alone doesn't seem to be the culprit. In other words, avoiding foods low in histamine may make a difference, but it seems that there's something else about these foods, apart from the histamine that they contain, that seems to be the problem.
An elegant series of experiments demonstrated this finding. In one study, the researchers specifically looked at patients who had gotten better after following the elimination diet. They then gave them a "challenge" meal, in which they had the patients eat these foods again. And then they watched to see if their hives would get worse.
In this case, the elimination diet was one that avoided all foods that were high in "pseudoallergens." Pseudoallergens are the foods and beverages that researchers had observed seemed to act as trigger foods for hives.
In this study, 73% of patients reported an improvement in their hives after 3 weeks of following a specific diet (known as the "pseudoallergen free" or PAF diet).
These patients were then given a "challenge" meal that contained a high level of pseudoallergens. After the challenge meal, every single patient experienced a worsening of their hives.
Then the researchers went further. They used an extract from whole tomatoes and fed it to the patients. Over 50% of the patients had their hives come back after they ate this extract. Bottom line: something about the tomatoes seemed to be an issue for a lot of these patients.
Thinking it might be the histamine in the tomatoes that was the problem, the researchers then gave the patients a tomato extract that was specifically high in histamine. However, only 15% of the volunteers reacted to this high-histamine extract.
In other words, something about the tomatoes seemed to trigger hives, but it didn't seem to be the histamine. [And we still don't know what it is about tomatoes that acts a trigger for hives.]
And it's not just tomatoes. Another study looked at 33 patients who had a known history of reactions to pseudoallergens.
Of this group, 76% reacted to whole tomatoes, 50% to a panel of common food additives, 47% to herbal extracts in oil, and 44% to white wine.
From the research done to date, it appears that these reactions are dose-dependent. In other words, eating just one of these foods, or a small amount of several of these foods, may not be enough to trigger a flare of hives.
On the other hand, if you eat enough of one of these foods, or eat a smaller amount of many of these foods together, you may have an issue. That cumulative dose may be enough to trigger a reaction for some people with hives.
Should I try a chronic urticaria/ chronic hives elimination diet?
Elimination diets should not be used in place of standard, proven therapy. BUT they can definitely be used in conjunction with standard therapy.
The standard therapy for chronic urticaria always starts with antihistamine medications by mouth. These therapies may need to be adjusted to find the right dose and the right combination of medications, but they're able to control chronic hives in most patients.
Adult patients who still have hives after starting standard therapy may want to consider this elimination diet. We recommend trying it for 3 weeks to see if it will help. If it does help, then I recommend adding back in one food, every few days, and paying attention to your hives.
If you're considering this elimination diet, you may find it helpful to check out my chart below, with more details, published in the medical journal Dermatology Practical and Conceptual.