Efficacy of Topical Agents in the Treatment of Chrysaora Chinensis Stings

The purpose of the study is to attempt to determine which treatment from commonly used treatments is the best at reducing pain and redness of the skin after a sting from a Portuguese Man of War, Chrysaora chinensis, or Chrysaora fuscescens.

Jellyfish stings are a common occurrence in many parts of the world causing significant morbidity to persons stung by jellyfish while participating in marine activities whether commercial or recreational. Much debate and confusion exist both in the medical literature and the common recommendations regarding how to treat persons stung by jellyfish. Specifically concerning what topical treatments are most efficacious at decreasing envenomation by nematocyst on skin, preventing the firing of un-discharged nematocyst, decreasing inflammation and pain resulting from envenomation by nematocyst. Antidotal recommendations and past studies have referenced numerous different topical treatments for jellyfish stings including but not limited to vinegar, urine, alcohol, distilled spirits, ammonia, bleach, acetone, bicarbonate slurry, lidocaine, meat tenderizer, Coca Cola, old wine, salt water, cold packs, hot water, and commercial products such as Stingose and Stingaid. Conflicting data exists regarding what works and what does not for nematocysts discharge, skin erythema, and pain reaction.

The investigators would like to investigate which treatment is best out of some of the more commonly studied treatments for reducing pain and erythema.

The investigators would like to complete a research study to try to bring some reasonable evidence to the field treatment of jellyfish stings, namely, the decontamination process (e.g., what can you put on a jellyfish sting that will be helpful, based on real data?).

The questions asked are as follows:

• What topical treatments for jellyfish stings actually decrease the amount of inflammation seen on a macroscopic level on the skin of humans?
• What topical treatments for jellyfish stings actually decrease the sensation of pain in humans?
• Do topical chemical treatments cause different outcomes when exposed to the above parameters?
• Do different species of jellyfish nematocysts react differently based on the type of topical chemical treatment used? What is the variation of effects of topical treatments based on the species of jellyfish sting?

Specifically, the investigators will be stinging human subject on both arms with a segment of tentacle for approximately 2 minutes. This will be followed by no treatment on one arm (control arm) and by treatment on the other arm with either: acetic acid (5%), sodium bicarbonate slurry (50%), papain slurry (70%), ammonia (10%), viscous lidocaine (4%), isopropyl alcohol (70%), or hot tap water (40 degrees Celsius). Outcomes measured will include pain and erythema.