Is it trying to fix itself by closing the airways?….Or is it just a reaction and not a defense.
In: 81
**Histamine** is a biochemical that has a significant role in both generalised and local immune responses. It is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.
As others have noted, allergic reactions of the type leading to anaphylactic shock are an immune system response that is out of proportion to the threat posed by an allergen. This causes a systemic flood of histamine through the body, far beyond the site of the initial stimulation.
This opens capillaries to allow antibodies to reach the site of the allergen, causing flushing of the skin and swelling of mucus membranes, and often the skin as well. Swelling of mucus membranes of the throat, trachea and bronchi will restrict breathing. In addition, this opening of the capillaries and other histamine effect on the circulatory system has the effect of lowering blood pressure, causing the “shock” of anaphylactic shock. In combination with the restricted airway, the human body is suddenly and significantly stressed, and other physiological responses to stress also kick in.
Epinephrine (as delivered from an Epipen) is used to reverse some of the effects of histamine during anaphylaxis. It has an impact on smooth muscle in the blood vessels, reversing the dilation and increasing blood pressure. It also relaxes the smooth muscles in the airways and lungs, countering the effects of swelling and making breathing easier. It is also used in this way to relieve asthma.
Latest Answers