As a bad sufferer of allergies I frequently have to take anti-histomines. Should I be doing this? Isn’t my body creating histomine for a reason? What benefit is histomine supposed to provide and what, if any, are the negative consequences of getting rid of it?
I mean, it’s supposed to do something, right?
Yes, your body creates histamine for a reason, and darn good ones, too. So let’s have no dissing of important compounds, shall we? 
Histamine is, among other things, an inflammatory mediator, i.e., it is produced and released in response to a chemical signal from a damaged site. This could be in response to an injury, a specific microorganism (e.g., pollens), or a chemical (e.g., bee stings.)
Some of the functions of histamine are:
To increase the local capillary permeability. This allows clotting proteins and antibodies to exit the bloodstream and directly interact with the cells.
Dilation of the capillary, to promote fluid movement to the inflammed site.
Aids in attracting white blood cells.
Stimulates mucus secretion and can cause smooth muscle contractions in bronchioles.
Not least of all, histamine is one of the three chemicals that aids digestion by stimulating active transport of H[sup]+[/sup] into the stomach lumen.
Don’t histamines also have something to to with quaternary structure (the way the molecule folds in it’s environment) of DNA? I think I remember that positievly charged histamines bind to the negatively charged phosphate groups.
Twain said that fleas (paraphrased) take a dog’s mind off the pain of being a dog. Same deal.
sorry for the delay in getting back here.
xcheopis, this important compound has made my life a living hell! But OK, it’s really on my side.
So now I must ask some obvious questions: If I’m cut or bruised would taking antihistamines slow down the healing process? And conversely, would exposing myself to allergens stimulate my production of histamines thus allowing cuts and bruises to heal more quickly?
Do anti-inflammatory meds interact in any way with histamine? I mean, if histamine is an inflammatory mediator wouldn’t it reduce the effectiveness of Ibuprofen, and conversely would antihistamines increase the effectiveness?
Why and how does histamine cause me to wheeze, sneeze, itch, bitch, tear, wear (i.e. thin of my patients)?
Why haven’t any of my serious injuries ever seemed to trigger an allergy attack?
AskNott, I’m not sure I follow. Are you saying that the negative allergic reactions caused by histamine are histamine’s way of diverting my attention from the pain/discomfort of an injury or a cat’s saliva? or is it meant to be a profound message for enlightenment (i.e. sneezing makes life interesting)? other?
Not asking for much, are ya? 
I’ll do my best, but I’m not an expert on histamine so be patient.
Originally posted by Moe
The honest answer is: I don’t really know, but blocking the effects of histimine (which is the function of anti-histimines) would likely slow down the healing process. While there are other mediators, histimine does play a critical role. I doubt that exposure to allergens would enable you to heal more quickly because the histamine is responding to two separate signals. One from the injured site and one from the allergen. The injured site would get the normal response and the allergen would get a hyper-response. So, you’d be bleeding and wheezing. What fun!
No, anti-inflammatories inhibit prostaglandin synthesis, not histamine synthesis. (The important inflammatory mediators are: histamine, complement, lymphokines, prostaglandins, and kinins.) One of the roles of prostaglandins is to sensitise the blood vessels to respond to the other mediators. In other words, inhibition of prostaglandin results in a lessened response to the inflammation and histamine production does not go into overdrive. (Among other things.)
No, for the reasons stated above.
Why? Because it likes you! OK, that’s a lie. Your allergy response to histamine involves:
Increase of mucous and mucosal flow. This is an effort to capture the allergen and wash it away.
Increases dilation of blood vessels and causes them to become “leaky”. This is what gives you the itchy, red skin. It seems like a bad thing but really, it’s only there to help. Under normal response conditions, this allows for protein-rich fluids to enter the tissue space where they can dilute any harmful substances, bring in vast quantities of oxygen (and other nutrients) and allows entry of clotting proteins. This is good. However, the hyper-reaction leads to hives, which is bad.
Contraction of the smooth muscles in the bronchioles. This might normally produce a good, healthy cough to expel the little buggers but a hyper-response leads to too much constriction, which leads to restriction of air flow, which leads to asthma, which leads to misery.
Watery eyes. Here, I’ll admit that I’m not familiar with the mechanisms by which histamine increases fluid production in the tear ducts but it does and that’s that.
All of the above lead to bitching.
Because it is not the histamine itself that is causing the initial trouble; it is the allergen. See, the allergen is what triggers the hyper-response. Your body is panicing every time it encounters the allergen ("Get it off! Get it off! Get it off!) but a regular, boring ol’ injury is a “yeah, yeah, you guys handle it” kinda thing. Capiche?
So let’s say I’m stung by a bee. I now have a foreign poison in my dermis. Is the swelling, etc., caused by my own body’s attempts to dilute and remove the poison?
Originally posted by xcheopis
Originally posted by Moe
Doesn’t Retin A induce an inflammatory response that encourages skin to heal?
::humble smile::
Thanks x! If I ever make peace with my allergies I’ll be sure to mention you
toadspittle, in part, yes. But some of that swelling is also caused by the toxin itself, not just the immune response. Also, the site of the sting is, itself, mechanically injured. Having holes poked into ones skin often leads to some swelling, as folks with tattoos and piercings can attest.
Christopher, sorry, the only thing I know about Retin A is that women who are neurotically concerned about wrinkles react towards it like junkies to high-grade smack.
Moe, you are most welcome, sir.
