Why undergoing this examination?

Histamine is a molecule present in almost all foods, and the ability to metabolize and eliminate it is different in each individual. This ability is essentially determined by the activity of the intestinal enzyme diamine oxidase (DAO). In people with normal DAO activity, histamine from the diet is rapidly degraded, but in people with reduced activity an excess of histamine in the blood is produced, increasing the likelihood of serious adverse effects. These adverse effects are known as DAO deficiency, or also as food histaminosis or histamine intolerance. The symptoms associated with DAO deficit are many and represent chronic pathologies of great prevalence in the population. Those affected by the DAO deficit do not necessarily have all the symptoms described, although the majority usually present at least three, with migraine being especially prevalent among them.

What is this exam?

The test evaluates the activity of the DAO enzyme. The DAO enzyme is incubated with a labeled substrate. After the action of the DAO enzyme, a labeled product, selectively extracted, is obtained. The extracted product is quantified with a beta counter, thus the signal being directly proportional to the activity of the DAO enzyme in the sample. The identification of reduced DAO activity, as an intrinsic factor that triggers migraine, enables effective preventive treatment of the disease, with an improvement in the quality of life of the patient.

For whom is it indicated?

• Specially indicated in cases of:
– Migraine and other vascular headaches.
– Gastrointestinal disorders: Especially those associated with Irritable Bowel Syndrome (IBS), such as constipation, diarrhea, satiety, flatulence or a feeling of bloating.
– Dermatological disorders, such as dry skin, atopy or psoriasis.
– Bone disorders, such as osteopathic pain.
– Muscular changes, such as muscle pain, often diagnosed as fibromyalgia.
– Chronic Fatigue.
– In childhood and adolescence is related to attention-deficit/hyperactivity disorder, and with Cyclic Vomiting Syndrome.




• Guaranteed from the experience of the Synlab group, the absolute European leader in laboratory diagnosis.
• Objective and detailed results report.

Extra information

• Take the exam preferably for the 24-72 hours following a migraine attack.
• Fasting is necessary 8 hours before undergoing the examination.
• It is necessary also to suspend inhibitory medication of DAO.
• This test cannot be carried out during pregnancy.

Delivery Time
7 working days
Type of Sample
1 mL of serum

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