Have you noticed when it is allergy season, advertisements for anti-histamines begin to show up on TV, radio, and local pharmacies? Marketing strategies focus on the misery of people suffering from congested noses, watery eyes, and itchy throats. But, is using antihistamines or drugs that "block" the effects of histamine in the body the right way to treat allergies?

Guess where the highest concentration of histamine is found in the body? It is found in your brain (1,2)! In fact, histamine is found in the same category of brain chemicals as dopamine (which is abnormal in Parkinson's disease) and serotonin (the drug Prozac tries to increase). Is it then not surprising that a common side effect of taking antihistamines is drowsiness or a type of "depression".

Prior to the discovery of antihistamines, allergies (including multiple sclerosis) were treated by giving histamine, and not antihistamines.

Antihistamines (such as Allegra & Benedryl) are standard treatments in allergies whether you have hay fever, hives, and asthma. Yet, there is potential risk in taking these medications. For example the once popular antihistamine Seldane was discontinued due to its association with heart problems, including death (3). Newer versions of antihistamines are claimed as being "safer" and "non-drowsy" yet they too have associations with danger (4).

A little history about histamine use

Prior to the development of antihistamine drugs, histamine was once the treatment of choice for allergic and autoimmune disorders. Clinical research published by Dr. Horton, MD in the United States during the 1930-1950's pioneered an effective management of multiple sclerosis, and headaches using only histamine. Thousands of patients received benefit from histamine (5, 6). The treatment became to be known as "histamine desensitization". The concept is similar to allergy shots for the treatment of asthma or hayfever, but instead of using pollen, dust, or grasses, small doses of histamine are used instead.

How does histamine work?

But it seems counter-productive to give doses of histamine to people who already have high levels in their bodies, right? Remember that the body is an amazing self-regulating machine. Basically by giving histamine to the body in small doses, the body responds by slowing down it's own production and eventually shutting itself off. You can imagine this concept is similar to the breaker switch in a fuse box. When there is an excess of electricity or an electrical hazard in a home, the breaker switches to the off position. Consequently, the power in the house is turned off. Similarly, the extra histamine in the body is turned off. The use of histamine, for example, stopped skin swelling and inflammation in ragweed-sensitive people when they were exposed to ragweed (7). In fact, a medical drug known to have "histamine-like" action has demonstrated a beneficial effect to grass-pollen sufferers' (8).

This exact concept in science is termed "auto-regulation". In fact, it is a basic principle taught in every medical school and in every general course in biochemistry, physiology, and genetics for how the body regulates it self!

Has medicine been misled in the treatment of allergies and immune system problems? Well, I hope that this article has sparked an interest in the idea of using histamine for treating allergies and autoimmune diseases. When used properly histamine therapy is very safe. In fact, histamine has demonstrated positive benefit in cancer (9, 10).

References

1. Knigge U, Warberg J. The role of histamine in the neuroendocrine regulation of pituitary hormone secretion. Acta Endocrin (Copenh). Vol. 124: pp. 609-619:1991.
2. Wada H, Inagaki N, et al. Is the histaminergic neuron system a regulatory center for whole-brain activity? TINS. Vol.14 (9): pp. 415-417:1991
3. Smith SJ. Cardiovascular toxicity of antihistamines. Otolaryngol Head Neck Surg. Vol. 111 (3 Pt 2): pp. 348-54: Sept 1994.
4. Day J. Pros and cons of the use of antihistamines in managing allergic rhinitis. J Allergy Clin Immunol. Vol. 103 (3 Pt 2): pp. S395-9: Mar 1999.
5. Horton B. The use of histamine in the treatment of specific types of headaches. JAMA: Vol. 116: 5: pp. 377-383: 1941.
6. Horton B. The clinical use of histamine. PostGraduate Medicine: Vol. 9: pp. 1-10, 88-100: 1951.
7. Ting S et al. Histamine suppression of in vivo eosinophil accumulation and histamine release in human allergic reactions. J Allergy Clin Immunol: Vol. 68: 1: pp. 65-71: 198.1
8. Snyman JR, et al. The influence of betahistine on the dynamics of the cutaneous hypersensitvity reaction in patients with grass pollen allergy. Immunopharmacology. 30(1):71-8: June 1995.
9. Rovere F et al. In vivo experiment demonstration that hyperhistamism counteracts tumor growth. Oncology Reports: Vol. 1: pp. 175-177: 1994.
10. Cricco GP, Davio CA, et al. Inhibition of tumor growth induced by histamine: In vivo and in vitro studies. Agents Actions: 38, Special Conference Issue: pp. C175-C177: 1993.