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*local skin treatment involves immediate nematocyte inactivation, analgesia, andremoval.

o Rinse the wound with sterile normal saline to prevent nematocyte activation. Although seawater can be used as a last resort, it carries marine pathogens intothe wound. Avoid using fresh water and rubbing the skin, since these activitiestrigger unfired nematocytes.

o Soak the wound in 5% acetic acid for 15-30 minutes to further inhibit nematocyte discharge. Although acetic acid inhibits nematocytes, it does not provide pain relief. Other possible inhibitors include 70% isopropyl alcohol or the papainfound in meat tenderizer to denature the proteinase toxins. Unfortunately, theseother inhibitors have little effect on nonproteinaceous toxins.

o After the inactivation, carefully remove any visible tentacles with forceps, followed by the removal of the nematocytes/nematocysts, as described in SurgicalCare.

o Apply topical anesthetics once the nematocytes/nematocysts are removed. Cold pack compresses at the sting site for 5-10 minutes relieve all but the most severe site pain. Avoid direct application of ice to the area, since the hypotonic water from the melting ice may stimulate unremovable, unfired nematocytes. Also, avoid hot compresses, since they increase systemic uptake of venom.

o Administer antihistamines and topical and systemic corticosteroids for severelocal reactions as well as to decrease the probability of serum sickness symptoms from the antivenin, provided no secondary concurrent infection is present.

o Administer muscle relaxants (eg, benzodiazepine, methocarbamol) for severe local spasms.

o Narcotic analgesias are appropriate for severe local pain not responding to topical anesthetics.

o Administer a tetanus shot as a prophylactic measure.

o Administer systemic antibiotics if signs of secondary infection exist.

* Systemic treatment

o Remove patient from danger.

o Remove patient from water to prevent drowning.

o Monitor ABCs to provide adequate airway, ventilation, and perfusion.

o Provide supportive care (eg, central venous monitoring, fluids, inotropic support, pressors for hypokinetic cardiac failure).

o Immobilize and sedate the patient to prevent rapid absorption of venom resulti

ng from muscle movement.

o Apply a lymphatic-venous compression bandage proximally to the sting site to reduce venous and lymphatic flow of the venom but not to stop arterial flow. Usually, a range of 40-70 mmHg for the upper extremity and 55-70 mmHg for the lowerextremity is used. Remove the bandaging only when the provider is ready to render systemic support and the antivenin has been initiated.

o Antivenin for box jellyfish envenomation is obtained from the Commonwealth Serum Laboratory of Melbourne, Australia. The dose is 1 ampule IV over 5 minutes or

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3 ampules IM with repeat doses administered according to clinical circumstances. Unfortunately, the antivenin is ineffective if the toxin already has entered acell.

o Anaphylaxis is rare, but can be treated with airway support, oxygen, intravascular resuscitation, epinephrine, H1 and H2 blockers, steroids, and a beta2-agonist nebulizer.

o Treat catecholamine-excess hypertension with phentolamine.

o Intraarterial urokinase has been anecdotally successful in the treatment of arterial vessel thrombosis-induced severe limb ischemia.

* Ophthalmic treatment

o Nonaqueous topical anesthetic drops followed by copious irrigation with isotonic normal saline are used. Avoid acetic acid irrigation, since it causes more damage than the nematocysts.

o Administer ophthalmic steroids to decrease the corneal inflammatory response.

o Beta-blockers and carbonic-anhydrase inhibitors are used for documented increased intraocular pressure resulting from the corneal jellyfish sting.

* Experimental treatments

o Monoclonal antibody against jellyfish toxin

o Phototherapy of the sting site with ultraviolet light to suppress immune response resulting in chronic lesions

o Verapamil adjunct to antivenin for decreasing venom-induced cardiotoxicity

o Gadolinium for inhibiting nematocyte firing through blockade of the calcium-permeable mechanosensitive ion channels involved in nematocyte activation

Surgical Care:

* Once the nematocytes are inactivated, they can be removed by dusting the areawith a paste of shaving cream, baking soda, and talc for 1 hour to coalesce thenematocyte, followed by scraping the area with a dull object (eg, spoon). Strongadhesive tape applied to the area and then removed also can be used.

* Clean ulcerating lesions 3 times per day, followed by application of antibiotic ointment (eg, erythromycin) effective against potential marine pathogens.

Consultations:

* Poison control centers or national aquariums may provide guidance in treatingjellyfish envenomation.

* Antivenom index published by the American Zoo and Aquarium Association lists the location, amount, and types of antivenom stores.

* Marine biologists may be consulted for nematocyst identification.

Activity: Rest and immobilization of the sting site is recommended to prevent rapid absorption of the venom into the circulation.