Assessing the Efficacy of First-Aid Measures in Physician sp. Envenomation, Using Solution and Blood Agarose-Based Models

Abstract

Stings from the hydrozoan species in the genus Physalia cause intense, immediate skin pain and elicit serious systemic effects. There has been much scientific debate about the most appropriate first aid for these stings, particularly with regard to whether vinegar use is appropriate (most current recommendations recommend against vinegar). We found that only a small percentage (≤1.0%) of tentaclecnidaedischargeduringastingeventusinganexvivotissuemodelwhichelicitsspontaneous stingingfromlivecnidariantentacles. WethentestedavarietyofrinsesolutionsonbothAtlanticand Pacific Physalia species to determine if they elicit cnidae discharge, further investigating any that did not cause immediate significant discharge to determine if they are able to inhibit cnidae discharge in response to chemical and physical stimuli. We found commercially available vinegars, as well as the recentlydevelopedStingNoMore® Spray,werethemosteffectiverinsesolutions,astheyirreversibly inhibited cnidae discharge. However, even slight dilution of vinegar reduced its protective effects. Alcohols and folk remedies, such as urine, baking soda and shaving cream, caused varying amounts of immediate cnidae discharge and failed to inhibit further discharge, and thus likely worsen stings.