This website is unique in that I use only scientifically founded information. I have reviewed all the English and German professional materials related to histamine adverse reactions available on PubMed.
The most important reference is the currently valid German guideline: https://pubmed.ncbi.nlm.nih.gov/34651098/
More detailed references can be found partly in my Wikipedia article (histamine intolerance), in my study published in the American Journal of Case Reports, and in our publication in the MDPI Journal of Clinical Medicine.
The previously valid German guideline, based on broad professional consensus, is available here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5346110