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

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

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

    Second Opinion

    Read expert perspectives on popular health topics.

  • 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

Large Families May Help Keep Allergies Away

But Early Infections Don't Seem to Be Reason for Protection

WebMD Health News

April 29, 2004 -- Having three or more siblings helps prevent allergies, a new study suggests.

In recent years, researchers have been diving deeper into the "hygiene hypothesis," which aims to explain why some people have allergies and some do not. The thought is that being exposed to more dirt and grime may actually decrease the risk of allergies. It suggests that advances in antibiotics and cleaner homes have contributed to increases in allergy, asthma, and eczema by decreasing rates of childhood infection.

Early studies have suggested that having more siblings may decrease the risk of allergies. But in this new study, researchers sought to determine if this is merely an effect of kids being exposed to more infections from other kids.

Danish researchers studied more than 24,000 mother-child pairs to try to get to the bottom of this dirt and allergy association -- specifically, whether exposure to infections early in life decreases the risk of allergies. The children were enrolled in the study when they were 6 to 18 months old.

The researchers were specifically looking at how many of these children developed eczema, a skin condition that causes a red, itchy rash and occurs in kids prone to allergies. In addition to a host of other questions, the moms were asked about the number of infections their kids had before 6 months of age.

The study appears in the current issue of the British Medical Journal.

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
woman with sore throat
lone star tick
Woman blowing nose

Send yourself a link to download the app.

Loading ...

Please wait...

This feature is temporarily unavailable. Please try again later.


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

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