Histamine Intolerance: What You Need to Know
Read on to learn more about the causes, symptoms, and treatments for histamine intolerance.
Histamine is a chemical called a biogenic amine. Basophils and mast cells mainly produce and store it. They are white blood cells involved in your body’s response to allergens.
When an allergen enters your body or comes into contact with your skin, your immune system sends out signals to release histamine. Histamine widens your blood vessels, allowing other substances in your body to travel to the area affected by the allergen. These substances then repair your tissues.
Although experts need more research to prove it, histamine intolerance may result from the body’s inability to break down histamine. Usually, an enzyme called diamine oxidase (DAO) breaks down histamine.
When someone has a DAO deficiency, histamine does not break down, building up in their system. An excess of histamine can come from foods that contain histamine or trigger its release in the body.
DAO deficiency can result from a genetic mutation, or it may be an acquired condition. Certain disorders — such as gastrointestinal and inflammatory bowel diseases — may cause DAO function impairment resulting in histamine intolerance symptoms.
A DAO deficiency can be reversible if it results from factors like alcohol or certain medications. Medications that can cause impaired DAO function include chloroquine, cimetidine, and veramapil.
Histamine intolerance can cause symptoms in many areas of the body.
Respiratory symptoms resulting from histamine intolerance may include:
Histamine intolerance can trigger many gastrointestinal symptoms, including:
Skin symptoms may include:
Related conditions that cause similar symptoms
The symptoms of histamine intolerance can be very similar to other conditions, such as food allergies and scromboid fish poisoning.
Scromboid fish poisoning occurs after an individual eats certain kinds of spoiled fish and can cause many of the same symptoms as histamine intolerance. Certain fish species contain high levels of histidine, which bacteria can convert to histamine. These levels are high enough to cause symptoms in almost anyone.
The difference between scromboid fish poisoning and suspected histamine intolerance is that scromboid fish poisoning does not result from an enzyme deficiency or a specific intolerance.
Because histamine intolerance is not a clinically-recognized condition, it does not have its own diagnostic criteria.
If you are experiencing symptoms of suspected histamine intolerance, doctors will typically try to eliminate other conditions.
The symptoms of histamine intolerance can be similar to food allergy symptoms. Therefore, doctors may recommend trying an elimination diet. An elimination diet involves cutting out foods that commonly trigger allergic reactions, such as dairy, shellfish, and peanuts.
Your doctors may also have you follow a low histamine diet to see if your symptoms improve.
Treatment for histamine intolerance may include a low histamine diet and medications.
Low histamine diet
People with suspected histamine intolerance may benefit from a low histamine diet. Certain foods and drinks contain high levels of histamine, including:
- foods that are fermented
- aged cheese
- meats and fish that are smoked or processed
It is important to note that some foods — such as mushrooms, soybeans, or nuts — do not contain high levels of histamine but may trigger histamine release in the body, causing symptoms.
Foods that are low in histamine include:
- fresh meat and fish
- noncitrus fruits
- dairy substitutes
- gluten-free grains
Although experts need more research, a 2020 research review suggested that a low histamine diet can result in a reduction in the presence and severity of histamine intolerance symptoms.
Some people with suspected histamine intolerance may benefit from antihistamines, which are drugs that block the effects or production of histamine. While antihistamines typically come in tablet form, they may also be available as liquids, lotions, nasal sprays, or eye drops.
Some researchers also proposed that DAO supplementation can help alleviate histamine intolerance symptoms and potentially allow for a less restrictive diet, but experts need more research on this topic, too.
If you take a medication that can cause a DAO deficiency, you may need to stop taking the medication and find an alternative.
With treatment, the outlook for people with histamine intolerance is generally good. It is important to get treatment because people who have histamine intolerance along with allergies can experience a dangerous buildup of histamine in their systems. This buildup can trigger serious symptoms such as asthma attacks or anaphylactic shock.
These are a few commonly asked questions about histamine intolerance. Dr. Elizabeth Feuille reviewed the answers.
Can histamine intolerance be cured?
Histamine intolerance is not definitively curable because experts cannot provide a clinical diagnosis yet.
However, if alcohol or a certain drug causes symptoms of histamine intolerance, eliminating those things may provide relief. Avoiding foods containing histamine, triggering histamine release, or interfering with histamine breakdown may also be beneficial.
Is histamine tolerance the same as allergies?
Histamine intolerance is not the same as allergies. With allergies, exposure to an allergen causes your immune system to release allergic proteins, including histamine.
In contrast, histamine intolerance symptoms may arise from an excess amount of histamine in your system that your body cannot break down. These symptoms often manifest after you consume certain foods or drinks, but this results from their histamine content and not an immune response to the foods or drinks themselves.
Histamine intolerance is a syndrome that may occur when your body cannot break down histamine, leading to a buildup of the chemical in your body. A deficiency of DAO, an enzyme that breaks down histamine, might cause histamine intolerance.
Common symptoms of histamine intolerance include bloating, increasing heart rate, flushing, itching, and breathing difficuulties. Doctors may recommend an elimination or low histamine diet to narrow down the cause of your symptoms.
Antihistamines may help alleviate symptoms. While DAO supplements are available, their benefits in suspected histamine intolerance require more study.
Talk with your doctor if you are experiencing symptoms consistent with histamine intolerance.