Skip to Content
Home > Wellness > Health Library > Jellyfish Stings: Allergic Reaction
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:
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.
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:
ByHealthwise StaffPrimary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency MedicineSpecialist Medical ReviewerDavid Messenger, MD
Current as ofNovember 14, 2014
Current as of:
November 14, 2014
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD
How this information was developed to help you make better health decisions.
To learn more, visit Healthwise.org
© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.