Understanding histamine intolerance

Histamine is a vital molecule with many extraordinary biological functions but an excess of it in the tissues can cause health problems. Histamine intolerance can cause symptoms similar to food allergy symptoms. Sometimes histamine intolerance may be connected to other health conditions such as irritable bowel syndrome, inflammatory bowel disease, and celiac disease. One thing to bear in mind is that histamine tolerance is not the same as food intolerance.

Different types of histamine intolerance

Histamine intolerance can be classified as such:

• Exogenous: histamine that comes from diet (ingested histamine) and, as it has not been deactivated in the digestive tract, has passed into the blood, causing food intolerance symptoms. Examples of this process are histamine intoxication (often from poorly preserved food) and enteral histamine syndrome (occurs in individuals with poor ability to remove histamine even in normal concentrations).

• Endogenous: accumulated histamine inside the body cells of. This is classified into sub-groups, depending on the mechanism that causes the release of excess histamine:

1. If the process is mediated by a type of antibody called IgE, it is an allergic process that may be triggered by pollens, mites, fungi, food proteins or foods. Its symptoms are often very characteristic and well known by allergy specialists.
2. If the process is not mediated by the IgE antibody, this is a non-allergic food histamine.
3.  Other situations of histamine intolerance where stress influences the release, excessive position to the sun etc. 

Symptoms of histamine intolerance

The problem in diagnosing histamine intolerance is its symptomatic nature. There may be a most significant symptom which prompts the patient to visit the corresponding specialist:

1. 30-40% of patients diagnosed with histamine intolerance come from general medicine, suffering from fibromyalgia or chronic fatigue.

2. 20-25% comes from trauma consultations due to problems of dehydration of intervertebral discs or others.

3. 10-12% comes from digestive consultations.

4. 4. A minority come from other consultations such as neurology, allergy, dermatology, etc.

This can cause the specialist to settle on a diagnosis and not distinguish if there are other symptoms that create suspicion of histamine intolerance. Additionally, if digestive symptoms predominate, the patient can think that the problem is being caused by certain foods and tries to eliminate the problem with an elimination diet, such as cutting out lactose or gluten.  This might show slight improvements, although the problem is not usually solved.

Common histamine intolerance symptoms include:

• Headache
• Diarrhoea
• Runny nose
• Watery eyes
• Rash
• Arrhythmia

Diagnosing histamine intolerance

For the correct diagnosis of histamine intolerance, studies are made of the patient’s histamine release. The patient's cells are stimulated with certain food antigens and the type of histamine response is assessed and analysed. .

Although during the diagnosis it is possible to think of one or several foods that have triggered the process, HANA syndrome does not have a cause-effect relationship with food intake as clear and immediate as an allergy, so the empirical diagnosis from this is impossible. 

What does treatment involve?

The basis of treatment histamine intolerance is a personalised therapeutic diet, which will include foods that the patient must not eat. . Normally, this includes milk or wheat, which is a big problem because of their ubiquity in processed foods. A large number of foods contain potential triggers that many would not consider or imagine, such as, for example, dairy proteins, which can be found in cold meats, sausages, types of bread, pasta, preserves, snacks etc.

The Andalusian Society for the Study of Food Intolerance (SAEIA) works to raise awareness among producers of the need for more natural and simple products with fewer components and also, clear labelling to help customers identify what they can and cannot eat or should and should not.