Histamine is a chemical that is normally found in the body. The actions of histamine include being a part of the immune system’s defense. Histamine acts a chemical messenger in the early alert system that detects chemical intruders into the body. The early alert system which utilizes histamine messengers includes mast cells (found in lymph nodes) and basophiles, one type of white 
blood cell (see blue histamine packets within the cells in the photo). When foreign proteins get into the body the mast cells and basophiles swallow and destroy them and release histamine. Histamine then diffuses into the surrounding tissues where it will dilate local blood vessels.
The dilated vessels will result in the blood flowing slower in the surrounding tissue. Slower moving blood through arteries that are larger than normal will tend to allow an increased amount of blood to leak out. This leaking blood contains additional chemical and white blood cells to help contain and eliminate any additional foreign proteins that have gotten through the body’s walls. This redness (from dilated blood vessels) and swelling (from increased fluid leakage out of the blood vessels) is inflammation. So histamine is one of the chemical messenger that initiates inflammation and protects your body from foreign ‘invaders’.
If histamine is released in larger amounts, it will spread further through the body causing increasing inflammation at more distant sites. Remote sites could include the eyes, nose and brain. In these situations, you might get watery eyes, runny nose, hives and neurological symptoms such as brain inflammation. An inflamed brain can give a wide range of symptoms depending on which nerves are weakest and most vulnerable (i.e. depression, anxiety, compulsions, etc.). If severe enough, anaphylactic shock will be the result as too many arteries throughout the body dilate and blood pressure drops to lethal levels.
At certain points, the inflammation process is opposed by the bodies inflammatory chemical such as cortisone. These anti-inflammatory chemicals will stop the inflammation process from spreading too far.
Combating excess histamine release or control with ‘anti-histamines’ will stop the symptoms of allergies but will not fix the cause. Why is the body releasing too many histamines? Are the histamine packets in the immune cells to fragile? Is the body producing too little cortisone? Why? If you cover up excess allergy symptoms with anti-histamines instead of finding and fixing the cause(s), the original problem continues to wreak havoc on your body, and the next problem from this cause might have much more severe consequences on your health! In addition, you are crippling your immune system from containing and eliminating foreign proteins that have gotten into your body.
Regulating histamine releases, as well as containing the duration of its effect, is a vitally important component of the body’s defenses. It will help attract your body’s defenses to deal with foreign substances that get inside of you. When histamine is excessively released or unopposed sufficiently by regulating chemical, inflammation can spread too far, and can cause mild to severe symptoms including anaphylactic reactions and death. The key is finding out: 1) if the right amount of histamines are being released upon normal stimulation (such as eating a normal food) and then 2) are you turning off the inflammation process at the right time. Once you determine these factors, it will be much easier to find the causes and hopefully permanent cures to prevent excessive histamine reactions in the future.
By Dr. John M. Wallman, DC
This article is not intended to offer a diagnosis or medical advice. It is offered strictly for educational purposes. Please consult members of your health care team directly to explore these or any other health care concepts.