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Jellyfish Stings: Allergic Reaction

Table of Contents


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:

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:


Credits for Jellyfish Stings: Allergic Reaction

Current as of: July 1, 2021

Author: Healthwise Staff
Medical Review: William H. Blahd Jr. MD, FACEP - Emergency Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
David Messenger MD


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