What happens when you have symptoms that are not fully understood by the medical community, or a condition that’s not universally accepted? It’s deeply frustrating not to have answers, and that’s often the experience of people living with symptoms of histamine intolerance. 

Histamine intolerance is a proposed condition that causes symptoms when histamine builds up in the body. One of the most overwhelming aspects of living with these effects is the ongoing debate over whether the condition even exists and what causes it.

In this article, we explore histamine intolerance testing. We also focus on how to conduct a low-histamine food challenge, as this is the primary tool people can use to identify triggers and better manage their symptoms over time.

Here’s the information you need to know. 

What is histamine intolerance?

Histamine intolerance (also known as enteral histaminosis or sensitivity to dietary histamine) is a medical theory that explains why some people experience a buildup of histamine throughout their body.

It is not currently recognized by the American Academy of Allergy and Immunology as a diagnosable medical condition.

Histamine is a chemical mediator released by leukocytes (including mast cells) in response to the identification of a potentially dangerous pathogen. After it’s released, it binds to histamine receptors throughout the body, initiating part of the inflammation cascade.

In most cases, histamine produces short-term effects that resolve quickly. But in some people, histamine builds up in the body when it’s not broken down at the pace it is produced or consumed, leading to symptoms.

This may be influenced by a range of factors, including diet, gut health, medications, and other underlying conditions, although no single cause has been confirmed.

Because symptoms can overlap with other conditions, your doctor may consider testing for causes such as:

• Mast cell activation syndrome (MCAS)
• Mastocytosis
• Systemic allergies

Symptoms of histamine intolerance

Having high histamine levels in the body can cause allergy-like symptoms. Because histamine receptors are located across the body, the severity, type, and duration of these symptoms vary greatly.

Some of the most commonly reported symptoms of elevated histamine levels include:

• Bloating
• Constipation
• Diarrhea
• Sneezing
• Nasal congestion
• Difficulty breathing
• High heart rate
• Headaches
• Migraines
• Itchiness
• Skin flushing

What is a histamine intolerance test?

Because histamine intolerance is not a confirmed medical condition, there is no definitive test to diagnose it.

This being said, your doctor may prescribe tests to help identify what may be causing your symptoms. 

Here's a breakdown of some of the most common tests for elevated histamine levels.

Histamine challenge test

This test involves taking 75mg of histamine while being monitored by a health professional. If you develop a reaction, it could indicate that you have high levels of histamine.

Serum diamine oxidase (DAO)

This test involves blood work that tests for serum diamine oxidase (DAO), the enzyme that breaks down dietary histamine. If your DAO levels are low, it may be causing elevated histamine levels. However, many factors affect DAO readings.

Skin prick test

A 1% histamine solution is pricked into the skin to produce a reaction. Unfortunately, this test cannot differentiate between histamine intolerance and allergies, so it’s primarily used for confirmation.

Fecal histamine levels

Fecal testing can detect high histamine levels. This test is not considered particularly accurate as intestinal microbiota produce histamine and can skew results.

Genetic testing

In rare cases, genetic testing can identify an underlying genetic condition that predisposes you to high histamine levels.

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Your doctor will likely suggest conducting a 14-day food challenge to identify food triggers in your diet. This involves eating a low-histamine diet, tracking your symptoms, and then slowly reintroducing foods to see how your body reacts.

How to conduct a histamine food challenge

A histamine food challenge, or a histamine elimination diet, is a great way to determine if your symptoms appear when you eat high-histamine foods. With the insights you gain, you can make changes to your diet and better manage your symptoms moving forward.

Step 1: Keep a food journal and symptom journal

Before starting any food challenge, you need to collect baseline health data. Later, you can use this to make comparisons.

Weeks before starting, keep a detailed food and symptom journal, including a list of your symptoms, their severity, and the foods you eat.

Step 2: Eat a low-histamine diet for 14 days

Remove all high-histamine foods from your diet.

Here are some examples of foods you might avoid:

• Alcohol
• Cured meats
• Fermented foods like kimchi and sauerkraut
• Chocolate
• Aged cheeses
• Tomatoes, eggplant, and spinach
• Fish
• Strawberries, pineapple, and citrus fruits
• Nuts and peanuts

You might focus on consuming the following low-histamine foods:

• Fresh, non-aged meat
• Salmon (fresh or flash frozen)
• Non-citrus fruits (apples, blueberries, mangoes, peaches, and pomegranates)
• Gluten-free grains (amaranth, arrowroot, buckwheat, millet, rice, quinoa)
• Non-dairy milks (almond, coconut, or hemp)
• Fresh vegetables
• Olive oil
• Coconut oil
• Almonds
• Potatoes
• Flax and chia seeds
• Butter and ghee
• Cream, cream cheese, and ricotta
• Soft cheeses that have not been aged or fermented

During the challenge, keep a detailed food and symptom journal. Track how you feel and what foods you eat, so over time, you can identify patterns to see what helps (and which foods might be triggers).

Note that it’s not possible to remove histamine completely as part of a healthy diet.

Step 3: Reintroduce foods and track your reactions

After two weeks of eating a low-histamine diet, you can start to add the high-histamine foods you have eliminated back in one at a time. A gradual approach will allow your body to adjust and for you to collect more information.

Important note: Not everyone responds the same to a low-histamine diet. Some people find their symptoms become less severe, while others are more affected by other factors, like how the food is prepared or stored. This is a trial-and-error approach that reveals insights about your body and health.

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Frequently asked questions

How do I get tested for histamine intolerance?

There are no definitive diagnostic tests for histamine intolerance, as it’s not a universally recognized medical condition.

If you think you may have histamine intolerance, speak to your doctor to explore potential causes and treatments, which can include making lifestyle changes to better manage your symptoms.

What are the signs of too much histamine in the body?

High levels of histamine in the body present similarly to having an allergic reaction. Because histamine is a chemical mediator that causes systemic inflammation, symptoms affect the entire body. Examples include bloating, itching, sneezing, rashes, headaches, flushing, and more.

Can you measure histamine levels with a blood test?

There is no blood test for elevated histamine in the body. That said, if you are experiencing ongoing, severe allergy-like symptoms, your doctor can order other tests, including histamine challenge testing, serum diamine oxidase blood work, skin prick tests, fecal histamine level testing, and genetic testing.

Disclaimer: Human Health is a health tracking platform and does not provide medical advice, diagnosis, or treatment. The information on this site is intended to support, not replace, conversations with qualified healthcare professionals.

Sources:

1. Histamine intolerance: fact or fiction?, The American Academy of Allergy Asthma and Immunology
2. Mastocytosis, The Cleveland Clinic
3. Histamine intolerance, The Cleveland Clinic
4. Histamine Intolerance: Symptoms, Diagnosis, and Beyond (2024)
5. Foods high in histamine, WebMD
6. Low histamine diet, Johns Hopkins Medicine‍
7. Serum tryptase, Medscape