This is how you can test for histamine intolerance

This is how you can test for histamine intolerance

The testing of histamine intolerance takes place in a step-by-step process.
The trend is towards non-invasive and clinical diagnosis of histamine intolerance. This includes keeping a symptom diary and a low-histamine diet. The diagnosis can be made with these two measures, possibly in combination with a provocation test.

More complex tests such as blood or urinalysis are now only of minor importance.

These tests are there

Testing of histamine intolerance is largely carried out clinically.

The first step is a detailed consultation with a doctor, during which other possible diagnoses are also excluded. This is followed by keeping a symptom diary for a few weeks. During this time one should not consciously avoid certain foods in order not to get distorted results.

In the third step, you usually start a so-called elimination diet. Consciously and with the advice of a doctor, you avoid histamine-rich foods and alcohol. During this time, the symptom diary will continue to be kept in order to be able to perceive changes. In the best case, the diet should be adhered to for 2-4 weeks. If symptoms improve, a diagnosis of histamine intolerance is likely.

In addition, a provocation test can be carried out under controlled conditions.

Several fluids are given to drink as part of this test. Some of these liquids contain histamine. In the best case, neither the patient nor the examiner know which liquids contain histamine and which do not (double-blind principle).
Histamine intolerance can also be diagnosed by testing blood samples. To do this, the first step is to determine the activity of diamine oxidase (DAO) and the total content of histamine in the blood.
If these tests do not produce clear results, further information can be obtained in a second step using molecular genetic methods. It is also possible to examine urine or stool. However, both tests are not very informative and are therefore rarely used.

Read more on the subject at:

• Symptoms of histamine intolerance
• Allergies

This doctor is testing

Histamine intolerance is usually carried out by a general practitioner or an allergist.

In this context, the doctor also makes the decision as to whether the diagnosis takes place via a prick test or via a blood sample. For the blood test, the doctor has to work with a laboratory that can adequately examine the samples for the histamine-processing enzymes and the histamine content in the blood.

How useful are online tests?

A large number of tests for diagnosing histamine intolerance are available on the Internet. These include, for example, questionnaires that are offered as self-tests.
These questionnaires can be used as a guide, but you should note the following:

• The symptoms of histamine intolerance are similar to the symptoms of other medical conditions.
• With a rigid questionnaire, it is hardly possible to shed light on the nuances, which are important in order to rule out other diagnoses.
• Such a questionnaire does not replace a visit to the doctor, who can give qualified statements about the cause of the complaints in an interactive conversation and his experience.

Furthermore, online sets are offered with which you can test directly at home with a small blood or urine sample whether you are intolerant or not. These sets are sometimes offered by dubious providers and should therefore not replace a visit to the doctor.

On the one hand, the statement of blood or urine tests is controversial anyway and people tend to distance themselves from it. On the other hand, it is questionable whether a small drop of blood or urine is sufficient to carry out comprehensive enzyme diagnostics.

In summary, it can be said that online tests are not really useful and should not replace a visit to the doctor.

What tests are there from the pharmacy?

The pharmacies that offer tests for histamine intolerance is rather untypical.

At most they can sell blood or urine tests, which can also be obtained on the Internet. These tests are not recommended.

A pharmacy is not even necessary in the diagnosis phase, as the most important steps are keeping a nutrition and symptom diary and a low-histamine diet.
A pharmacist, like the doctor, can of course give advice and support you in changing your diet.

Cost of a test

If the tests are indicated for histamine intolerance, i.e. if they are justified, the doctor can settle this with a statutory health insurance doctor or a private doctor.

Often no invasive diagnostics are necessary to make the diagnosis of histamine intolerance, so that only the consulting costs are incurred, which are also covered by the health insurance.
Blood or urine tests on the Internet can be very variable in price. There are tests from around 30 euros, but there is no limit to the cost online.

Prick test

In the prick test, a small amount of histamine is injected between the layers of the skin.

After an initial short waiting period, the skin area is examined and the skin reaction is assessed. A skin reaction with redness and wheals to histamine is completely normal and therefore histamine is also used as a positive control in other allergy prick tests.
In order to obtain information about a histamine intolerance, wait another 50 minutes after the skin reaction has developed. If the wheal has not changed by then, it can be assumed that the breakdown of histamine is slower.

However, the prick test does not provide any information about how the patient processes the histamine taken orally, i.e. through the mouth. However, since most of the histamine intolerances are oral intolerances, the prick test is not very informative.

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Testing in the blood

Histamine is broken down by two enzymes. On the one hand from diamine oxidase (DAO) and from histamine-N-methyltransferase (HNMT).

The activity of DAO can be measured in the blood, as can the level of histamine. If the activity of the DAO is reduced, one can conclude that there is a histamine intolerance.

There are also cases when the activity of the DAO is normal, but there is an excess of histamine in the blood. This can be the case with hay fever, for example.
The activity of the HNMT cannot be measured in the blood. In order to detect a disturbance in this enzyme, one has to carry out a molecular genetic diagnosis that goes beyond a simple blood test.
The blood tests only play a minor role in histamine intolerance. On the other hand, if you are on a successful low-histamine diet, it still makes sense to determine both vitamin B6 and copper in the blood. These two substances are important for the work of the DAO. A deficiency could also be a reason for histamine intolerance.

Testing in the urine

Methylhistamine can be measured in urine. The methylhistamine content is not only dependent on the histamine content consumed, but is also influenced by protein-rich food.
This means that an increased level of methylhistamine can be present in the urine even if the diet was low in histamine but high in protein.

From this it can be concluded that the urine test hardly plays a role in the diagnosis of histamine intolerance and that its results must be critically questioned.