Histamine intolerance test: which blood values actually mean something

Search for "histamine intolerance test" and within a minute you'll find a handful of providers promising you a DAO value in your blood for 60 to 120 euros. We sell blood tests ourselves. And this is still our answer: the blood test that confirms histamine intolerance does not exist.

That's an awkward sentence for a company that draws blood. But a test that wrongly flags almost four in every ten healthy people isn't a diagnosis, in my view. That's a sales tool, and we won't sell it as one.

What blood testing can do here is at least as useful.

It can rule out the conditions that cause exactly the same symptoms: a real IgE allergy, a mast-cell problem, or inflammation sitting somewhere else entirely. The wider background is in our overview of histamine intolerance, its symptoms and its causes. Below, it's purely about the test.

Is there a reliable histamine intolerance test?

No, and the guidelines say so themselves. The 2021 guideline of the German-speaking allergy societies concludes that laboratory parameters such as serum diamine oxidase have proven inconclusive (PMID 34651098). The 2017 version put it even more bluntly: a reliable objective laboratory test for this diagnosis is lacking (PMID 28344921).

However confident a provider sounds, that's where the science stands.

Histamine intolerance also isn't an allergy. Your immune system takes no part in it. The Dutch Voedingscentrum puts it this way: in an intolerance, your body reacts to food without the immune system being activated.

That difference isn't academic. An allergy leaves a trace in your blood, namely specific IgE. An intolerance leaves almost nothing behind that a laboratory can measure.

And that's the whole problem.

What is the DAO value and why isn't it enough?

DAO stands for diamine oxidase, the enzyme in your gut wall that breaks down histamine from food. The reasoning behind the test sounds logical: less DAO enzyme means less breakdown, so more histamine. In practice, though, a low serum DAO doesn't reliably separate people with symptoms from people without them (PMID 37836530).

A Slovenian study from 2023 set the test against a clinical assessment. The result: roughly 71% sensitivity and 61% specificity (PMID 37836530). Those percentages sound abstract, so work them through.

Take 100 people who genuinely have histamine intolerance. The DAO test misses about 29 of them. They get a normal result, go home, and keep searching.

Now take 100 people who don't have it. About 39 of them get flagged as suspect anyway. A low result, a fright, and a diet resting on nothing.

The researchers say it themselves: don't lean on a DAO measurement alone for this diagnosis. A specificity of 61% sits close to a coin toss. Something like that can't carry the weight of a diagnosis.

On top of that, your DAO value also drops with alcohol, with certain medicines, and with damage to your gut wall. So a low result can mean any number of things. That makes it a slippery histamine test.

Can my GP test histamine?

Usually not, and there's a reason. A GP generally won't order a DAO measurement for these symptoms, simply because the result doesn't settle the question. The route runs through your symptom pattern, a food-and-symptom log, and ruling out the conditions that look like it.

That isn't penny-pinching. It's the logical response to a test that discriminates too weakly. Thuisarts.nl, the patient site of the Dutch GP college NHG, shows how GPs weigh the whole picture in food hypersensitivity.

What do blood histamine and a histamine-free diet actually tell you?

Histamine in your blood swings within minutes: it's released, taken up and broken down at a pace that a single tube of blood never captures. As a static marker, a blood histamine value is weak. The most recent overview of the research puts no lab value at the centre, but a supervised elimination-and-reintroduction diet (PMID 32824107).

That applies to more than DAO. Several routes are sold as a histamine test, and not one of them confirms the diagnosis.

That diet runs in three steps. You take histamine-rich products out for a few weeks. If the symptoms settle, you bring those products back step by step, one at a time.

What happens during that reintroduction says more than any number on your result ever will.

Just don't do it on your own. The Voedingscentrum warns explicitly against experimenting by yourself with cutting products out. A strict histamine-free diet drops cheese, wine, fish, tomato, spinach and virtually everything fermented.

Without a dietitian looking over your shoulder, you run a real risk of deficiencies. And you run the risk of avoiding something for months that isn't causing your symptoms at all. We've seen this pattern before with other intolerance tests and wrote up which food intolerance tests work and which don't.

Which blood values are actually useful for these symptoms?

The honest gain from blood testing here isn't confirming, it's excluding. Flushing, cramps, headache and a runny nose also fit a real IgE allergy, a mast-cell problem, and inflammation elsewhere. Those are testable questions, and the table below shows what each value can do and what it firmly cannot.

That bottom row is the one most webshops don't show you.

We put it in on purpose.

The Voedingscentrum estimates that roughly 1 to 4% of the population has a food allergy or food intolerance, rising to 4 to 6% in children. Some of those people walk around with symptoms that look like histamine but aren't. For them, excluding isn't a consolation prize, it's the fastest route to an answer.

What the top rows are worth depends on how you read them. A positive IgE result means sensitisation, not automatically an allergy. We work that out in what a food allergy test does and doesn't show and in what a raised IgE in your blood means.

If your eosinophils are too high, that can point to allergic or other inflammatory activity. In our experience, that's more often a reason to look further than a DAO value has ever been.

What can you do right now?

Start with a log. For two weeks, write down what you eat and drink, with the time and the amount, and which symptoms follow, with the time on those too. That pattern is the most usable information you can gather yourself, and it costs you nothing.

One exception matters: with breathlessness, with swelling of your lips, tongue or throat, or with a reaction that looks like anaphylaxis, you wait for nothing. Call 112 or go to the out-of-hours GP service. That's acute care, not a moment to have blood drawn first.

Then take your log to your GP. They look at the whole: your symptoms, your food, your medication and whatever else is going on. If you want to exclude the look-alikes with blood work, these are the values that earn their place.

• Inhalation allergy panel or food allergy panel: specific IgE, to weigh a real allergy.
• Tryptase: a pointer towards your mast cells.
• Eosinophils: allergic or other inflammatory activity.

You can pick those values individually through building your own blood test. Histamine sits in there too, and you're free to tick it. I just wouldn't hang a conclusion on it without a symptom log and without a GP looking on.

If you want your inflammation markers and blood count in the same draw, the extended health checkup is a logical baseline.

One thing I'd give anyone with these symptoms: don't start at the test. Start at the pattern. The test comes after, and only to rule something out.

References

1. Reese I, Ballmer-Weber B, Beyer K, et al. Guideline on management of suspected adverse reactions to ingested histamine. Allergol Select. 2021;5:305-314. PMID 34651098.
2. Arih K, Đogo A, Kolenc Peitl P, et al. Evaluation of Serum Diamine Oxidase as a Diagnostic Test for Histamine Intolerance. Nutrients. 2023;15(19):4246. PMID 37836530.
3. Reese I, Ballmer-Weber B, Beyer K, et al. German guideline for the management of adverse reactions to ingested histamine. Allergo J Int. 2017;26(2):72-79. PMID 28344921.
4. Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, et al. Histamine Intolerance: The Current State of the Art. Biomolecules. 2020;10(8):1181. PMID 32824107.
5. Voedingscentrum. Voedselovergevoeligheid. Available via voedingscentrum.nl.
6. NHG and Thuisarts. NHG guideline on food hypersensitivity and coeliac disease, with patient information via thuisarts.nl.

Every blood test result at Vitalcheck includes a professional assessment by a BIG-registered doctor. A blood value is not a diagnosis: always discuss treatment decisions with your GP.