Some claim that certain foods, including citrus for example, directly activate mast cells (like some drugs do in IgE-independent way) and thus induce histamine-mediated symptoms, being so called "pseudoallergens". In Russia medical practitioners tend to use term "Histamine liberators". I couldn't find any scientific basis for that. EAACI and AAAAI do not recommend pseudoallergen-free diets. However, are there any experimental data on such possibility? I'm aware of histamine-rich foods (controversial too in terms of clinical significance), but what about direct mast cells/basophil activation?
- If someone has a history of food allergy, say allergic to peanut and he was exposed to peanut not long ago. S/he should have IgE formed in the blood and in tissues (likely sitting on mast cells). If s/he ingests peanut again (likely not intentionally), then the peanut (allergen in this case) will bridge with two IgE units sitting on the surface of mast cells, that would trigger mast cells to release preformed granules. The most likely mediator to be released in the granules would be histamine. So, that sequence of events clinically is called allergic reaction.
- Ingestion of histamine-rich food is different from true allergic reaction. For instance, I had a physician friend who ingested spoiled tune fish sandwich right before the surgery. Right in the middle of surgery, he was hit by generalized flushing, violent vomiting and almost passed out. He had developed hypotension. Fortunately, his colleagues carried him to ER and he was saved. We proved he had not IgE against tune fish after the evaluation.
- Shih-Wen Huang, MD
Shih-Wen Huang , sorry, I was asking about evidence. The only paper claiming that food-derived products causes direct mast degranulation is doi: 10.1067/mai.2002.121309., but as you can see it's quite flawed in terms of methodology and statistics. I actually found another one where authors failed to show direct MC degranulation with food products - 10.1016/j.jaci.2007.12.990. I've had a short conversation with Allen Kaplan who confirmed that pseudoallergy of this type is a myth.
- Badges
- Science topic
- Similar topics
- Philosophy
- Ethics