Histamine intolerance (HIT) is a controversial syndrome, in which the body is believed to react to histamine released by certain foodstuffs. Symptoms include among other things headache, urticaria and abdominal discomfort. Several fruits, nuts, spices and food additives have been regarded as pseudoallergens. Since there is no objective investigation to prove HIT, the diagnosis is based on symptoms. On the basis of literature, better clinical studies are needed. Because the phenomenon remains unclear, use of the terms histamine intolerance and pseudoallergens is not recommended.