Think You Have Allergies? Think Again.

Have you heard about histamine intolerance? There are a lot of similarities between histamine issues and allergies--the information in this post can help you sort it all out.

Learn what histamine issues are and what to do about them in this post.

woman blowing her nose with text overlay


Like so many people I know, I have struggled with mild to moderate eczema off and on my entire life.

After modifying my diet drastically in order to nurse my son who has food allergies, my eczema took a turn to be the worst it has ever been.

The red patches on my hands were so awful looking that people would ask me if I had been burned. It definitely wasn’t fun to deal with the questions or the pain from eczema itself.

I knew that eczema was commonly triggered by food allergies or sensitivities, but I had done an elimination diet and wasn’t eating anything that affected me. In addition, I had eliminated all grains and most of the other major allergens in order to comply with my son’s diet. According to popular diets such as the paleo diet, GAPS, and The Body Ecology Diet, everything that I was doing should have been healing my eczema. Instead, it continued to get worse and worse.

As is usual for me, I began to research what could possibly be causing my condition to get worse instead of better. I also began to notice that sometimes specific foods seemed to make my skin worse, but other times they didn’t bother me at all.

After hours of searching, I finally hit upon something that made sense.

The foods that were bothering me were all high in histamine, and there was a condition known as histamine intolerance that caused symptoms such as eczema.

By removing grains from my diet I had actually increased my intake of high histamine foods greatly, thereby exacerbating my symptoms.

Through more research and testing I have realized that histamine intolerance is exactly what was causing my eczema, but when I share that with others they look at me like I am crazy! Histamine intolerance is a fairly new term in the medical community, so it is not widely recognized.

In today’s post and in its follow-up I will be sharing with you just exactly:

  • what histamine intolerance is
  • how to tell if you have it, and
  • how to go about healing your body so it can better deal with histamine

What is histamine?

Histamine is an organic compound found in the body that is most known for its role in the inflammatory response. However, it plays other important roles, as well. It is produced and stored by basophils in the blood and mast cells in the tissues and is typically associated with allergic reactions.

Is histamine bad?

Histamine tends to have a bad reputation because it is released during allergic reactions, causing a runny nose, watery eyes, decreased breathing ability, hives, and other typical allergy symptoms. In reality, though, histamine plays a crucial role in many bodily processes.

“We require histamine for brain function, it’s a neurotransmitter. We require histamine for digestion because it’s the trigger for the release of gastric acid, which is always released when we start to eat – it’s the first stage of breakdown of protein in the stomach, for example – and we require it constantly for protection because histamine is one of the ways the body fights infection or any adverse event in the body because these events will result in inflammation as the result of histamine release.” (Dr. Janice Joneja)

We literally could not survive without histamine in our bodies. But at some point it becomes too much of a good thing.

What is histamine intolerance?

The terms “histamine intolerance,” “histamine sensitivity,” and “histamine excess” are used in medical literature, but they all mean the same thing. When too much histamine builds up in the body, it causes symptoms that are often similar to traditional allergy symptoms.

Histamine intolerance is not actually an allergy to histamine.

Interestingly, histamine intolerance is not an allergy at all despite its similar symptoms. The symptoms are so similar because allergic reactions always involve the release of histamine in the body.

Histamine intolerance actually comes from other processes that either make excess histamine or render the body unable to properly break down histamine that is present.

Histamine & Allergies - Think You Have Allergies? Think Again!

Symptoms of Histamine Intolerance

So what are the symptoms of histamine intolerance? They can be broken down into three main categories: respiratory distress, digestive tract distress, and skin distress--all typical allergy symptoms. Of course individual symptoms will vary, but histamine intolerance can cause:

  • Itching (especially of the skin, eyes, ears, and nose)
  • Hives
  • Eczema or other rashes
  • Swelling (especially in mouth and throat)
  • Hypotension (a drop in blood pressure)
  • Heart racing
  • Nasal congestion
  • Sinus pressure
  • Dry Skin
  • Joint pain / achiness
  • Post-nasal drip
  • Runny nose
  • Irritate, watery, red eyes
  • Headaches
  • Insomnia
  • Confusion or irritability
  • Eczema
  • Heartburn, Indigestion, or other digestive distress
  • Diarrhea, constipation, irritable bowel syndrome
  • A hangover-like feeling after exposure to high levels of histamine

All of these symptoms beg the question:

Where does this excess histamine come from?

Why do some people have too much histamine and some people don’t?

The analogy of a bucket is often used to describe histamine intolerance. Histamine is poured into the bucket (the body) from three different sources.

Source #1: Necessary Histamine

There is always some histamine in the bottom of the bucket because it is necessary for basic body processes such as brain function, digestive function, and protection.

Source #2: Allergic Reaction

The second source of histamine is when the body has an allergic reaction to something.  This "something" can be either environmental or food. Some people have very few allergies and, therefore, allergies don’t add much histamine to their buckets. Others have multiple allergies, and their bucket fills quickly.

Source #3: High Histamine Foods

The last source of histamine for the bucket is high histamine foods in the diet. If an individual’s bucket is already fairly full of histamine from the first two sources, histamine from the third source, the diet, can cause the bucket to overflow. When the bucket overflows, symptoms occur.

What is tricky about histamine intolerance is that the level of histamine in the bucket varies greatly from day to day and from one season to the next.

For example, when pollen counts are high, there will be more histamine in the bucket. At such a time, a small amount of histamine in the diet could cause symptoms. At other times, when environmental allergies are sparse, a person could consume more histamine containing foods without the bucket overflowing.

It is difficult to determine which histamine-containing foods might be offenders because if the level of histamine in the bucket is low before a high histamine food is consumed, the histamine in that food might not cause the bucket to overflow into symptoms. At other times, when the level of histamine in the bucket is higher, that same food will cause a reaction. Some individuals seem to have larger buckets, meaning that their bodies can effectively process more histamine without a reaction. Others seem to have smaller buckets or more sources of histamine that make them more prone to symptoms.

Causes of Histamine Intolerance

Histamine intolerance is the difference between how much histamine there is in the system and the body’s ability to break that down. Because researchers are just beginning to recognize this condition, there aren’t a lot of exact answers about its cause.

Most of what we think we know is speculation or the result of preliminary research.

- Genetics

It's thought that histamine intolerance is partially genetic, as people with certain genes seem to be more predisposed to it than others. However, those without the genes can suffer as well, so other factors are at play that might vary per person.

- Enzyme Deficiency

Some individuals appear to have trouble producing one or the other of the two enzymes needed to degrade histamine- Diamine Oxidase (DAO) and Histamine N-methyltransferase (HNMT). When the body is unable to effectively inactivate histamine, even at normal levels, there is a buildup of histamine resulting in adverse symptoms.

- Too much Histamine

Others might produce histamine too efficiently, either as a result of having too much Histidine Decarboxylase (which changes the amino acid histidine into histamine) or because they have issues with methylation. An imbalance of gut flora can also be a cause of excess histamine because certain species of bacteria actually produce histamine. If these species dominate the gut, they will produce a constant stream of histamine that the body may be unable to keep up with.

Any of these causes alone or in combination make it easier for the histamine bucket to overflow, resulting in the above-mentioned symptoms. It is entirely possible that there is another cause of histamine intolerance that has not yet been discovered, as well.

Histamine Intolerance and Gut Health

Histamine intolerance is related to gut health, as that is one of the primary places that histamine enters the body. The gut is also where histamine degrading enzymes are formed.

Of course, what isn't related to gut health, right?

Many people with histamine intolerance are nutrient deficient. As a result, they often have or are at risk for other gut-related conditions such as autoimmune diseases, gluten intolerance, and inflammatory bowel diseases. Although histamine intolerance can occur without a leaky gut, they most commonly go hand in hand, and leaky gut exacerbates the symptoms of histamine intolerance.

It also follows that histamine intolerance is connected to vagus nerve health. You can see more about this in the follow up post on histamine intolerance remedies.

In this follow-up to this post we'll address:

- if you are histamine intolerant
- what foods are high in histamine, and
- how to get on the path to healing

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Do you, or does someone in your family suffer from allergies?
Have you heard about histamines before?

CC image courtesy of mcfarlandmo via Flickr

Erin Ter Beest - Writer for Whole New Mom

About Erin

Erin Ter Beest lives and blogs in Alto, Wisconsin with her son, Sawyer, and husband, Casey. She dabbles in traditional foods, alternative health, raising chickens and goats in their sustainable house. More of Erin’s thoughts on all things food, nutrition, farm, and home can be found at her website, Natural Wonderer.

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  1. Hi, My son used to have red hot ears and was a mystery to us for many months. We eventually realised it was a multi vitamin capsule (made out of gelatin/pork) that was the culprit. Yes I fully concur with you. Histamine intolerance can manifest itself in many forms & symptoms are sometimes similar to those of an allergic reaction

  2. Hi,

    I'm curious if you ended up introducing gluten free grains, specifically white rice, once you transitioned over to a low histamine type diet. Similar to you, I transitioned into an Autoimmune Paleo diet and my symptoms (specifically skin) got way worse. I am now doing low histamine and seeing improvements - but have been conditioned to be wary of grains because of my experience with paleo and AIP.

    Is white rice usually OK to have?

    1. Hi again - I know I already answered you but your comment here is more detailed. White rice is demonized by many but I have read about its prebiotic benefits as well when prepared properly so I think it's a very interesting food. Keep in mind that this is Adrienne responding and not Erin, who wrote the post 🙂