DAN Medical Frequently Asked Questions

Jellyfish Stings

What is the best way to care for a jellyfish sting?

Jellyfish describes an enormous number of marine animals capable of inflicting a painful, and occasionally life-threatening, sting. These include fire coral, hydroids, jellyfishes (including "sea wasps") and anemones. The stings occur when the victim comes into contact with the creature's tentacles or other appendages, which may carry millions of small stinging cells, each equipped with venom and a microscopic stinger.

Depending on the species, size, geographic location, time of year and other natural factors, stings can range in severity from mild burning and skin redness to excruciating pain and severe blistering with generalized illness (nausea, vomiting, shortness of breath, muscle spasm and low blood pressure). Broken-off tentacles that are fragmented in the surf or washed up on the beach can retain their toxicity for months and should not be handled, even if they appear to be dried out and withered.

The dreaded box jellyfish (Chironex fleckeri) of northern Australia contains one of the most potent animal venoms known to man. A sting from one of these creatures can induce death in minutes from cessation of breathing, abnormal heart rhythms and profound low blood pressure (shock).

The Treatment

BE PREPARED TO TREAT AN ALLERGIC REACTION FOLLOWING A JELLYFISH STING. If possible, carry an allergy kit, including injectable epinephrine (adrenaline) and an oral antihistamine.

The following therapy is recommended for all unidentified jellyfish and other creatures with stinging cells:

1. If the sting is believed to be from the box jellyfish (Chironex fleckeri), immediately flood the wound with vinegar (5 percent acetic acid). Keep the victim as still as possible. Continuously apply the vinegar until the victim can be brought to medical attention. If you are out at sea or on an isolated beach, allow the vinegar to soak the tentacles or stung skin for 10 minutes before attempting to remove adherent tentacles or to further treat the wound. In Australia, surf lifesavers (lifeguards) may carry antivenin, which is given as an intramuscular injection a first aid measure.

2. For all other stings flush the area with large amounts of sea water to remove any remaining tentacles.
3. Immerse the affected area in hot water for 30 to 90 minutes to neutralize any undischarged nematocysts.
4. Remove any remaining tentacle pieces with forceps/tweezers.
5. Shave the area using shaving cream and a safety razor.
6. Apply hydrocortisone cream or lotion.
7. Monitor for allergic reaction or infection.
8. Apply warm(113F/45 degrees C max) packs to control the pain. This may be repeated as necessary.
9. If the victim has a large area involved (entire arm or leg, face, or genitals), is very young or very old, or shows signs of generalized illness (nausea, vomiting, weakness, shortness of breath or chest pain), seek help from a doctor. If a person has placed tentacle fragments in his mouth, have him swish and spit whatever potable liquid is available. If there is already swelling in the mouth (muffled voice, difficulty swallowing, enlarged tongue and lips), do not give anything by mouth, protect the airway and rapidly transport the victim to a hospital.

   For more information on marine life injuries, see the complete article by Paul S. Auerbach, M.D., M.S. on Marine Life Trauma from the Jan/Feb 1998 issue of Alert Diver.