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

Jellyfish Stings: Allergic Reaction - Topic Overview

The reaction that you have to a jellyfish or Portuguese man-of-war sting depends on many things. The potency of the venom changes with the type of jellyfish and also is stronger during some seasons than in others. Other things that affect the severity of your reaction include:

  • Your size, age, and general health.
  • The location and how much of your body (surface area) was stung.
  • The size or number of jellyfish or tentacles that stung you.

The pain from jellyfish and Portuguese man-of-war stings may be intense and may last for several hours. The skin at the site of the stings may look dusky or bluish purple. Blisters and deep sores (ulcers) may develop. Healing is generally a slow process that may take many weeks. Permanent scars may occur at the site of a sting.

Recommended Related to First Aid

Dehydration and Heat Illness in Children

Children are more prone to dehydration and heat illness than adults because they have more body surface area per pound of weight. Young athletes, practicing hard in the summer heat, are at particular risk. Learn to recognize the early warning signs of heat stress. Your knowledge could save a child's life.

Read the Dehydration and Heat Illness in Children article > >

Small children are at risk for stings in the mouth if they put a jellyfish or portion of a tentacle in their mouths. A sting to the mouth or throat can cause sudden and severe swelling, which can be life-threatening.

Problems from jellyfish or Portuguese man-of-war stings may develop right away or be delayed for several hours or days. A severe allergic reaction (anaphylaxis) may affect any body system and require emergency care. Symptoms can include any of the following:

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
1
Next Article:

Jellyfish Stings: Allergic Reaction Topics

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