Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier
WebMD

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine
WebMD

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion
    WebMD

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community
    WebMD

    Community

    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Allergies Health Center

Font Size
A
A
A

Risky Allergic Reaction: Chemical Clues

Inflammatory Chemical Called PAF Linked to Anaphylaxis
By
WebMD Health News
Reviewed by Louise Chang, MD

Jan. 4, 2008 -- Researchers have found two chemical clues that may help them tame sudden, severe allergic reaction (anaphylaxis).

The first clue: People with anaphlyaxis have high blood levels of an inflammatory chemical called platelet-activating factor (PAF).

The second clue: Anaphylaxis patients have low blood levels of PAF acetylhydrolase, an enzyme that breaks down PAF.

Those patterns may lead to new drugs to block PAF and treat anaphylaxis, Canadian researchers report.

The scientists compared blood samples from anaphylaxis patients to those from people without anaphylaxis. They concluded that too much PAF and too little PAF acetylhydrolase were a dangerous combination, and the greater the gap between levels of the two chemicals, the greater the risk to the anaphylaxis patient.

But PAF didn't cause anaphylaxis by itself. The patient also had to come in contact with his or her allergen, which for some patients was peanuts or insect stings.

Peter Vadas, MD, PhD, and colleagues report their findings in The New England Journal of Medicine. Vadas works in Toronto at St. Michael's Hospital.

The study may also lead to better tests to diagnose anaphylaxis, writes A. Wesley Burks, MD, in an editorial published with the study. Burks works in the allergy and immunology division of Duke University Medical Center's pediatrics department.

Today on WebMD

man blowing nose
Make these tweaks to your diet, home, and lifestyle.
Allergy capsule
Breathe easier with these products.
 
cat on couch
Live in harmony with your cat or dog.
Woman sneezing with tissue in meadow
Which ones affect you?
 

blowing nose
Article
woman with sore throat
Article
 
lone star tick
Slideshow
Woman blowing nose
Slideshow
 

Send yourself a link to download the app.

Loading ...

Please wait...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

cat lying on shelf
Article
Allergy prick test
VIDEO
 
Man sneezing into tissue
Assessment
Woman holding feather duster up to face, twitching
Quiz