La intolerancia a la histamina (HIT) es un trastorno común asociado a la alteración del metabolismo de la histamina. No obstante, a menudo se diagnostica erróneamente como otras enfermedades debido a su falta de manifestaciones clínicas específicas. La HIT no cobró importancia hasta principios del siglo XXI.
Informes recientes revelan una estrecha relación entre la migraña y los trastornos gastrointestinales (GI), como la enfermedad celíaca (EC) y la sensibilidad al gluten no celíaca (NCGS). La EC es un trastorno genético autoinmune, que afecta la mucosa del intestino delgado.
Histamine is the major mediator of IgE- and non-IgE-mediated allergic reactions upon allergen or
hapten contact. Reduced histamine degradation capacity was associated with atopic eczema as well as with nonimmunological
histamine intolerance.
Low-histamine diets are currently used to reduce symptoms of histamine intolerance, a disorder in histamine homeostasis that increases plasma levels, mainly due to reduced diamine-oxidase (DAO) activity. These diets exclude foods, many of them of plant origin, which patients associate with the onset of the symptomatology.
Histamine intolerance represents a controversially discussed disorder. Besides an impaired degradation of orally supplied histamine due to diamine oxidase (DAO) deficiency, a deranged gut flora may also contribute to elevated histamine levels
Diagnosis of histamine intolerance (HIT) has been based on low serum diamine oxidase (DAO) values, functional gastrointestinal disorders and improvement of symptoms with a histamine-reduced diet (HRD). In a retrospective analysis of outpatients’ charts we identified 101 patients with HIT. After a median of 13 months, a questionnaire was distributed to the patients so that they could be classified into four diet-compliance groups.
Diamine oxidase (DAO) catabolizes and inactivates histamine, a key player in a wide range of invalidating conditions, such as migraine and chronic spontaneous urticaria (CSU). The highest expression of DAO occurs in the gastrointestinal tract, possibly to control the burden of histamine intake from food.
Twenty-two adult patients were recruited and completed four weeks of histamine-free diet. The USS and UAS scores each showed significant differences before and after the histamine-free diet (p=0.010, p=0.006). There was a significant reduction in plasma histamine level after the histamine free-diet, compared with baseline (p=0.010). However, DAO activity did not change after the histamine-free diet (p=0.165).
A total of 75% of the patients had a benefit from the low-histamine diet. Thirty-four of 56 patients (61%) reached the primary endpoint of the study, an improvement of UAS 4 of ≥3. Overall, a significant reduction from 9.05 to 4.23 points (P = 0.004) was achieved; the average reduction in a strongly affected subgroup was 8.59 points (P < 0.001). DAO activity remained stable.
