Histamine intolerance is often hard to spot due to its varied spectrum of symptoms. Your doctor can look for distinctive symptoms and troubles and whether they occur after ingestion of histamine rich foods.

If a histamine intolerance is suspected, the activity of the histamine degrading enzyme DiAminoOxidase (DAO) in the blood can be measured using the D-Hit diagnostic kit. For further information consult an allergist  or allergy clinic.

A special diet low in histamines can also tell you whether you are suffering from histamine intolerance. This diet should be recommended by a doctor who specializes in intolerances or allergies or a registered dietician. In case of a genuine histamine intolerance the symptoms will cease rapidly.  

Recently a novel dietetic food has become available that contains the histamine degrading enzyme DAO in capsules, to be taken before a meal. If the usual symptoms fail to appear, the patient can be assumed to suffer from a genuine histamine intolerance.