DAO diamino-oxidase histamine intolerance
DAO diamino-oxidase measurement from blood
Do you ever get a headache or a feeling of anxiety or fear out of the blue without knowing exactly why? Do you get red cheeks from drinking red wine? Do you get an itchy tongue or runny nose when you eat banana, avocado or eggplant? Is it difficult for you to fall asleep? Are you a woman with an irregular menstrual cycle? If the answer to one or more questions was "yes," then the cause may be a histamine intolerance.
Histamine intolerance
Histamine intolerance is caused by your body's inability to break down excess histamine properly. This can be caused by a congenital defect, which means that insufficient enzymes are produced in the intestines that break down histamine. Alcohol consumption or the intake of certain medications can also block the production of enzymes, causing histamine to be absorbed into the bloodstream instead of being broken down in the intestines.
Medications that can cause this are: Acetylcystein, Ambroxol, Aminophyllin, Amitriptylin, Chloroquin, Clavulansäure, Droperidol, Isoniazid, Metamizol, Metoclopramid, Propafenone, and Verapamil.
If the result is higher than 10, you most likely do not have histamine intolerance
- results higher than 10 U/ml histamine intolerance unlikely
- result between 3-10 U/ml histamine intolerance probable
- result lower than <10 U/ml histamine intolerance very likely
This test examines whether there is a deficiency of the enzyme diamine oxidase. This enzyme breaks down excess histamine in the intestine. Histamine intolerance causes diarrhea and symptoms such as itching, stuffy nose, insomnia or headache.
Inhibition of DAO activity occurs by substances such as alcohol or drugs (acetylcysteine, ambroxol, aminophylline, amitriptyline, chloroquine, clavulanic acid, isoniazid, dipyrone, metoclopramide, propafenone, verapamil).
Ingestion of Diphenhydramine and Haprine lead to increased DAO concentration. Increased DAO activity is also seen in pregnancy (formation of DAO in the placenta).
Caution! Do not perform this test on hot days, as the sample should not get too hot during shipping by medical mail.
When using anti-histamines, you cannot do this test. Or you should be able to agree with your doctor to stop the medication for 5 days.












