Question about histamine level

Quote:Originally posted by Adele:
[b]When I was first diagnosed with PA, the allergist explained that when I had an ana reaction - the histamine level in my blood was high because of the reaction.

My two questions: #1: Does this histamine level stay high forever?

#2: Could someone please explain if the immune system produces histamines specific to each allergen? Or is the histamine released during a peanut reaction the same type of histamine that is released when you have hayfever?[/b]

Hope I can help!

1. No, at least not once the 'trigger' is truly removed. Histamine is actually a 'second messenger' in the chemical cascade which happens during an allergic reaction. So IgE binds to its recognition site on an allergen, and at that point it triggers [i]mast cell degranulation.[/i] Mast cells basically act like little 'bags' of histamine and other messenger molecules. These then go on to recruit additional responses via receptors at many other cell types.

How long the elevation in serum histamine lasts isn't really clear-- it may depend on a lot of different factors. Some people can continue to have symptoms for weeks after a single triggering event.

2. Histamine is histamine. Let me see if I can find a picture.

Anaphylaxis (for reasons that aren't even clear to the real experts in immunology, as far as I can tell) triggers a much amplified response. So a small exposure triggers a HUGE release of histamine. Hay fever a less robust one.

Does this help?

Jackpot!

Histamine metabolism explained... with pictures. This explains where histamine comes from (chemically speaking) and where it goes and what it does.

And it also includes nice discussion of histamine receptor pharmacology, for those interested. (Benadryl's chemical structure is toward the bottom of the page.)

[url="http://www.neurosci.pharm.utoledo.edu/MBC3320/histamine.htm"]http://www.neurosci.pharm.utoledo.edu/MBC3320/histamine.htm[/url]

Thanks Corvallis Mom! I was hoping you would answer.
Much appreciated.

can I ask then...my 1yr old got her hand into my sons yogurt container...within about 15min her eyes were red lined and her nose became a faucet(with sneezing). I gave Benadryl and it stopped. That was Fri...it's Sun and her nose is still running, so I started wondering it if was a cold? Could she still be reacting? Is she elevated because of the yogurt exposure(milk allergy)? Since it can stay elevated, does it cause reactions/symptoms to continue? Full of questions, sorry!!! I have been giving her Benadryl to help with the runny faucet nose. Thanks [img]http://uumor.pair.com/nutalle2/peanutallergy/smile.gif[/img]

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Chanda(mother of 4)
Sidney-8 (beef and chocolate, grasses, molds, weeds, guinea pig & asthma)
Jake-6 (peanut, all tree nuts, eggs, trees, grasses, weeds, molds, cats, dogs, guinea pig & eczema & asthma)
Carson-3 1/2 (milk, soy, egg, beef and pork, cats, dog, guinea pig and EE)
Savannah-1 (milk and egg)

[This message has been edited by chanda4 (edited April 22, 2007).]