What increases histamine in the human body, and are there oral forms of intake to stimulate this increase?
Yep. Try spoiled fish.
Histamine Poisoning (Scombroid Fish Poisoning): An Allergy-Like Intoxication
Histamine poisoning results from the consumption of foods, typically certain types of fish and cheeses, that contain unusually high levels of histamine. Spoiled fish of the families, Scombridae and Scomberesocidae (e.g. tuna, mackerel, bonito), are commonly implicated in incidents of histamine poisoning, which leads to the common usage of the term, “scombroid fish poisoning”, to describe this illness. However, certain non-scombroid fish, most notably mahi-mahi, bluefish, and sardines, when spoiled are also commonly implicated in histamine poisoning. Also, on rare occasions, cheeses especially Swiss cheese, can be implicated in histamine poisoning.
The symptoms of histamine poisoning generally resemble the symptoms encountered with IgE-mediated food allergies. The symptoms include nausea, vomiting, diarrhea, an oral burning sensation or peppery taste, hives, itching, red rash, and hypotension. The onset of the symptoms usually occurs within a few minutes after ingestion of the implicated food, and the duration of symptoms ranges from a few hours to 24 h. Antihistamines can be used effectively to treat this intoxication.
Histamine is formed in foods by certain bacteria that are able to decarboxylate the amino acid, histidine. However, foods containing unusually high levels of histamine may not appear to be outwardly spoiled. Foods with histamine concentrations exceeding 50 mg per 100 g of food are generally considered to be hazardous. Histamine formation in fish can be prevented by proper handling and refrigerated storage while the control of histamine formation in cheese seems dependent on insuring that histamine-producing bacteria are not present in significant numbers in the raw milk.
Lehane, L. & Olley, J. (2000). Histamine fish poisoning revisited. International Journal of Food Microbiology, 58, 1-37.