Abstract

ROLE OF HISTAMINE AND HISTAMINE INTOLERANCE, A REVIEW

Abhishek Borkar*, Shubhada Bhopale, Nandkishor Deshmukh, Ravikumar More, Vishal Padghan

ABSTRACT

Histamine and its receptors (H1R–H4R) play a crucial and significant role in the devel- opment of various allergic diseases. Mast cells are multifunctional bone marrow-derived tissue-dwelling cells that are the major producer of histamine in the body. H1R are expressed in many cells, including mast cells, and are involved in Type 1 hypersensitivity reactions. H2R are involved in Th1 lymphocyte cytokine production. H3R are mainly involved in blood–brain barrier function. H4R are highly expressed on mast cells where their stimulation exacerbates histamine and cytokine generation. Both H1R and H4R have important roles in the progression and modulation of histamine-mediated allergic diseasesAn im- paired histamine degradation based on reduced DAO activity and the resulting histamine excess may cause numerous symptoms mimick- ing an allergic reaction. The ingestion of histamine-rich food or of alcohol or drugs that release histamine or block DAO may provoke diarrhea, headache, rhinoconjunctival symptoms, asthma, hypoten- sion, arrhythmia, urticaria, pruritus, flushing, and other conditions in patients with histamine intolerance. Symptoms can be reduced by a histamine-free diet or be eliminated by antihistamines. However, because of the multifaceted nature of the symptoms, the existence of histamine intolerance has been underestimated, and further studies based on double-blind, placebo-controlled provocations are needed. In patients in whom the abovementioned symptoms are triggered by the corresponding substances and who have a negative diagnosis of allergy or internal disorders, histamine intolerance should be con- sidered as an underlying pathomechanism.

Keywords: Histamine intolerance, histamine, diamine ox- idase, food intolerance, allergy.