Cubozoan Sting-Site Seawater Rinse, Scraping, and Ice Can Increase Venom Load: Upending Current First Aid Recommendations

A Sting Beyond the Skin: Jellyfish Envenomation Presenting With Paralytic Ileus and Acute Urinary Retention

Jellyfish envenomation typically causes localized pain and systemic reactions, but rare complications such as acute urinary retention and paralytic ileus can occur. We report a case of a 21-year-old fisherman from northern Sri Lanka who developed urinary retention and paralytic ileus following a jellyfish sting. He initially experienced severe pain and itching, followed by acute urinary retention, progressive abdominal distension, vomiting, and absent bowel opening. Imaging confirmed paralytic ileus without mechanical obstruction. The patient was managed conservatively with catheterization, bowel rest, intravenous fluids, analgesia, and nasogastric decompression, leading to full recovery within 48 hours. Although the exact mechanism remains unclear, previous studies have hypothesized that jellyfish neurotoxins may affect autonomic regulation. This study highlights the need for awareness of rare urological and gastrointestinal complications following jellyfish stings and emphasizes the importance of timely supportive management.

2024 American Heart Association and American Red Cross Guidelines for First Aid

Codeveloped by the American Heart Association and the American Red Cross, these guidelines represent the first comprehensive update of first aid treatment recommendations since 2010. Incorporating the results of structured evidence reviews from the International Liaison Committee on Resuscitation, these guidelines cover first aid treatment for critical and common medical, traumatic, environmental, and toxicological conditions. This update emphasizes the continuous evolution of evidence evaluation and the necessity of adapting educational strategies to local needs and diverse community demographics. Existing guidelines remain relevant unless specifically updated in this publication. Key topics that are new, are substantially revised, or have significant new literature include opioid overdose, bleeding control, open chest wounds, spinal motion restriction, hypothermia, frostbite, presyncope, anaphylaxis, snakebite, oxygen administration, and the use of pulse oximetry in first aid, with the inclusion of pediatric-specific guidance as warranted.

Aquatic envenomation: First aid and prevention tips for US waters

ABSTRACT

Envenomation by an aquatic animal can produce distressing and occasionally life-threatening signs and symptoms. Common vectors of exposure in the US are cnidaria and venomous fish. Prompt recognition and treatment may help manage distressing symptoms, limit subsequent tissue destruction, and minimize the risk of more serious complications.

Jellyfish Stings: A Review of Skin Symptoms, Pathophysiology, and Management

With the surge in the human coastal population and the increasing frequency of human activities along the coast, cases of marine envenomation, particularly jellyfish envenomation, have notably risen. Jellyfish stings can induce a spectrum of symptoms that vary in severity, encompassing skin injuries, acute systemic venom effects, delayed indirect sequelae, and even fatality, causing significant distress to patients. Among these manifestations, the occurrence of skin lesions following jellyfish stings is prevalent and substantial. These lesions are characterized by evident blister formation, development of bullae, subcutaneous hemorrhage, erythema, papules, wheal, ecchymosis, and ulceration or skin necrosis. Local cutaneous manifestations may persist for several weeks or even months after the initial sting. Despite aggressive treatment, many skin injuries still result in significant pigmentation or scarring after recovery. To address this issue effectively, it is imperative to conduct comprehensive evidence-based medical research, elucidate various components within jellyfish venom, and elucidate its pathogenic mechanism to develop targeted treatment programs. This article aims to review the skin symptoms, pathophysiology, and management of jellyfish stings. Such considerations can provide comprehensive guidance to medical professionals and the public and minimize the harm caused by jellyfish stings.

Hot-Water Immersion (HWI) or Ice-Pack Treatment (IPT) as First Aid for Human Envenomation by Marine Animals? Review of Literature

Envenomation by marine animals poses a significant health concern globally, affecting both local residents and tourists in coastal regions. The primary objective of this review is to critically evaluate the existing scientific literature to determine the most effective first-aid treatment for envenomations caused by marine animals, specifically whether hot-water immersion (HWI) or ice-pack treatment (IPT) provides the best immediate care. This comprehensive review covers a wide range of marine envenomations, from jellyfish stings to stingray injuries. While our focus is primarily on the efficacy of HWI and IPT, we also explore the role of cold-water treatment as a result of its relevance and similarity to ice-pack applications. In addition, we examine other treatments mentioned in the literature, such as medications or vinegar, and highlight their findings where applicable. To provide a clear and structured overview, we summarised the articles in separate tables. These tables categorise the type of research conducted, the marine species studied, the region of origin of the marine species, and the key findings of each study. Our analysis of the available evidence indicates a general consensus in the scientific community on the effectiveness of HWI or IPT for envenomation by marine animals. However, when treating those injuries, it is crucial to consider all factors since there is no universally superior treatment due to the diverse nature of marine habitats.

Evaluation of a Guest Lecture on Medical Emergency of Box Jellyfish Envenomation Pathophysiology and First Aid for Medical Students

Introduction

Lethal box jellyfish envenomation has been reported in Indonesia and other countries; therefore, medical students should be equipped with related knowledge. The aim of this study was to evaluate the results of summative exams by student cohort and gender and determine the factors that contribute to success in the summative exams after novel intensive instruction in box jellyfish envenomation pathophysiology and first aid in undergraduate medical students in Surabaya, Indonesia.

Methods

This study used explanatory sequential mixed methods, consisting of a cross-sectional study and interviews. A total population sampling of 203 sixth-semester students was employed. Student cohort, gender, previous semester grade point average (GPA), and English proficiency test (EPT) were considered. All statistical tests were carried out using IBM® SPSS® Statistics version 24.0 for Macintosh. The study was complemented by interviews conducted with 20 students.

Results

The one-way ANOVA test showed that students from the 2016 cohort had significantly higher mean scores in the exam than the 2015 and 2014 cohorts (p=0.002). Independent samples t-test showed that such differences were not gender-specific (p=0.249). In the binary logistic regression, the GPA in the previous semester was the only factor that contributed to success in the summative exam (OR 3.031, 95% CI: 1.520-6.044). All students commented that the lecture and practicum were interesting and beneficial. However, some considered that the language barrier might have prevented them from understanding the topic well.

Conclusion

Results of the summative exam differed by the student cohorts, and previous semester GPA was a predictor of success in the summative exam.

Interventions for the symptoms and signs resulting from jellyfish stings

BACKGROUND

Jellyfish envenomation is common in many coastal regions and varies in severity depending upon the species. Stings cause a variety of symptoms and signs including pain, dermatological reactions, and, in some species, Irukandji syndrome (which may include abdominal/back/chest pain, tachycardia, hypertension, cardiac phenomena, and, rarely, death). Many treatments have been suggested for these symptoms, but their effectiveness is unclear. This is an update of a Cochrane Review last published in 2013.

OBJECTIVES

To determine the benefits and harms associated with the use of any intervention, in both adults and children, for the treatment of jellyfish stings, as assessed by randomised and quasi-randomised trials.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and Web of Science up to 27 October 2022. We searched clinical trials registers and the grey literature, and conducted forward-citation searching of relevant articles.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs of any intervention given to treat stings from any species of jellyfish stings. Interventions were compared to another active intervention, placebo, or no treatment. If co-interventions were used, we included the study only if the co-intervention was used in each group.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane.  MAIN RESULTS: We included nine studies (six RCTs and three quasi-RCTs) involving a total of 574 participants. We found one ongoing study. Participants were either stung accidentally, or were healthy volunteers exposed to stings in a laboratory setting. Type of jellyfish could not be confirmed in beach settings and was determined by investigators using participant and local information. We categorised interventions into comparison groups: hot versus cold applications; topical applications. A third comparison of parenteral administration included no relevant outcome data: a single study (39 participants) evaluated intravenous magnesium sulfate after stings from jellyfish that cause Irukandji syndrome (Carukia). No studies assessed a fourth comparison group of pressure immobilisation bandages.  We downgraded the certainty of the evidence due to very serious risk of bias, serious and very serious imprecision, and serious inconsistency in some results.  Application of heat versus application of cold Four studies involved accidental stings treated on the beach or in hospital. Jellyfish were described as bluebottles (Physalia; location: Australia), and box jellyfish that do not cause Irukandji syndrome (Hawaiian box jellyfish (Carybdea alata) and major box jellyfish (Chironex fleckeri, location: Australia)). Treatments were applied with hot packs or hot water (showers, baths, buckets, or hoses), or ice packs or cold packs.  The evidence for all outcomes was of very low certainty, thus we are unsure whether heat compared to cold leads to at least a clinically significant reduction in pain within six hours of stings from Physalia (risk ratio (RR) 2.25, 95% confidence interval (CI) 1.42 to 3.56; 2 studies, 142 participants) or Carybdea alata and Chironex fleckeri (RR 1.66, 95% CI 0.56 to 4.94; 2 studies, 71 participants). We are unsure whether there is a difference in adverse events due to treatment (RR 0.50, 95% CI 0.05 to 5.19; 2 studies, 142 participants); these were minor adverse events reported for Physalia stings. We are also unsure whether either treatment leads to a clinically significant reduction in pain in the first hour (Physalia: RR 2.66, 95% CI 1.71 to 4.15; 1 study, 88 participants; Carybdea alata and Chironex fleckeri: RR 1.16, 95% CI 0.71 to 1.89; 1 study, 42 participants) or cessation of pain at the end of treatment (Physalia: RR 1.63, 95% CI 0.81 to 3.27; 1 study, 54 participants; Carybdea alata and Chironex fleckeri: RR 3.54, 95% CI 0.82 to 15.31; 1 study, 29 participants). Evidence for retreatment with the same intervention was only available for Physalia, with similar uncertain findings (RR 0.19, 95% CI 0.01 to 3.90; 1 study, 96 participants), as was the case for retreatment with the alternative hot or cold application after Physalia (RR 1.00, 95% CI 0.55 to 1.82; 1 study, 54 participants) and Chironex fleckeri stings (RR 0.48, 95% CI 0.02 to 11.17; 1 study, 42 participants). Evidence for dermatological signs (itchiness or rash) was available only at 24 hours for Physalia stings (RR 1.02, 95% CI 0.63 to 1.65; 2 studies, 98 participants).  Topical applications One study (62 participants) included accidental stings from Hawaiian box jellyfish (Carybdea alata) treated on the beach with fresh water, seawater, Sting Aid (a commercial product), or Adolph's (papain) meat tenderiser. In another study, healthy volunteers (97 participants) were stung with an Indonesian sea nettle (Chrysaora chinensis from Malaysia) in a laboratory setting and treated with isopropyl alcohol, ammonia, heated water, acetic acid, or sodium bicarbonate. Two other eligible studies (Carybdea alata and Physalia stings) did not measure the outcomes of this review.  The evidence for all outcomes was of very low certainty, thus we could not be certain whether or not topical applications provided at least a clinically significant reduction in pain (1 study, 62 participants with Carybdea alata stings, reported only as cessation of pain). For adverse events due to treatment, one study (Chrysaora chinensis stings) withdrew ammonia as a treatment following a first-degree burn in one participant. No studies evaluated clinically significant reduction in pain, retreatment with the same or the alternative treatment, or dermatological signs.

AUTHORS' CONCLUSIONS

Few studies contributed data to this review, and those that did contribute varied in types of treatment, settings, and range of jellyfish species. We are unsure of the effectiveness of any of the treatments evaluated in this review given the very low certainty of all the evidence. This updated review includes two new studies (with 139 additional participants). The findings are consistent with the previous review.

Effect of Rinse Solutions on Rhizostoma pulmo (Cnidaria: Scyphozoa) Stings and the Ineffective Role of Vinegar in Scyphozoan Jellyfish Species

Rhizostoma pulmo is a widely distributed scyphozoan in the Mediterranean Sea. Their stings result mainly in erythema, small vesicles, or/and pain, and cause a high number of bathers to seek assistance from first-aid services during the summer season. Despite the threat that jellyfish stings represent to public health, there is disagreement in the scientific community on first-aid protocols, with the dispute largely centered around the effectiveness of vinegar. In the present research, we investigated the effect of commonly used rinse solutions on nematocyst discharge in R. pulmo and the effect of vinegar on three more scyphozoans (Aurelia sp., Cassiopea sp., and Rhizostoma luteum). Scented ammonia, vinegar, and acetic acid triggered nematocyst discharge in R. pulmo. Vinegar also caused nematocyst discharge in Aurelia sp., Cassiopea sp., and R. luteum. In contrast, seawater, baking soda, freshwater, urine, and hydrogen peroxide were considered neutral solutions that did not induce nematocyst discharge. These results indicate that the use of vinegar, acetic acid, or commercial products based on these compounds is counterproductive. Their use can worsen pain and discomfort caused not only by R. pulmo stings but also by those of any scyphozoan. The use of seawater is recommended for cleaning the R. pulmo sting site until an inhibitor solution that irreversibly prevents nematocyst discharge is discovered.

Raising Awareness on the Clinical and Forensic Aspects of Jellyfish Stings: A Worldwide Increasing Threat

Jellyfish are ubiquitous animals registering a high and increasing number of contacts with humans in coastal areas. These encounters result in a multitude of symptoms, ranging from mild erythema to death. This work aims to review the state-of-the-art regarding pathophysiology, diagnosis, treatment, and relevant clinical and forensic aspects of jellyfish stings. There are three major classes of jellyfish, causing various clinical scenarios. Most envenomations result in an erythematous lesion with morphological characteristics that may help identify the class of jellyfish responsible. In rare cases, the sting may result in delayed, persistent, or systemic symptoms. Lethal encounters have been described, but most of those cases happened in the Indo-Pacific region, where cubozoans, the deadliest jellyfish class, can be found. The diagnosis is mostly clinical but can be aided by dermoscopy, skin scrapings/sticky tape, confocal reflectance microscopy, immunological essays, among others. Treatment is currently based on preventing further envenomation, inactivating the venom, and alleviating local and systemic symptoms. However, the strategy used to achieve these effects remains under debate. Only one antivenom is currently used and covers merely one species (Chironex fleckeri). Other antivenoms have been produced experimentally but were not tested on human envenomation settings. The increased number of cases, especially due to climate changes, justifies further research in the study of clinical aspects of jellyfish envenoming.

Refinement and Neutralization Evaluation of the F(ab')2 Type of Antivenom against the Deadly Jellyfish Nemopilema nomurai Toxins

Jellyfish stings threaten people's health and even life in coastal areas worldwide. Nemopilema nomurai is one of the most dangerous jellyfish in the East Asian Marginal Seas, which not only stings hundreds of thousands of people every year but also is assumed to be responsible for most deaths by jellyfish stings in China. However, there is no effective first-aid drug, such as antivenoms, for the treatment of severe stings by N. nomurai to date. In this study, we prepared a N. nomurai antiserum from rabbits using inactivated N. nomurai toxins (NnTXs) and isolated the IgG type of antivenom (IgG-AntiNnTXs) from the antiserum. Subsequently, IgG-AntiNnTXs were refined with multiple optimizations to remove Fc fragments. Finally, the F(ab')₂ type of antivenom (F(ab')₂-AntiNnTXs) was purified using Superdex 200 and protein A columns. The neutralization efficacy of both types of antivenom was analyzed in vitro and in vivo, and the results showed that both IgG and F(ab')₂ types of antivenom have some neutralization effect on the metalloproteinase activity of NnTXs in vitro and could also decrease the mortality of mice in the first 4 h after injection. This study provides some useful information for the development of an effective antivenom for N. nomurai stings in the future.

Differing Effects of Vinegar on Pelagia noctiluca (Cnidaria: Scyphozoa) and Carybdea marsupialis (Cnidaria: Cubozoa) Stings-Implications for First Aid Protocols

The jellyfish species that inhabit the Mediterranean coastal waters are not lethal, but their stings can cause severe pain and systemic effects that pose a health risk to humans. Despite the frequent occurrence of jellyfish stings, currently no consensus exists among the scientific community regarding the most appropriate first-aid protocol. Over the years, several different rinse solutions have been proposed. Vinegar, or acetic acid, is one of the most established of these solutions, with efficacy data published. We investigated the effect of vinegar and seawater on the nematocyst discharge process in two species representative of the Mediterranean region: Pelagia noctiluca (Scyphozoa) and Carybdea marsupialis (Cubozoa), by means of (1) direct observation of nematocyst discharge on light microscopy (tentacle solution assay) and (2) quantification of hemolytic area (tentacle skin blood agarose assay). In both species, nematocyst discharge was not stimulated by seawater, which was classified as a neutral solution. In P. noctiluca, vinegar produced nematocyst discharge per se, but inhibited nematocyst discharge from C. marsupialis. These results suggest that the use of vinegar cannot be universally recommended. Whereas in case of a cubozoan C. marsupialis sting, the inhibitory effect of vinegar makes it the ideal rinse solution, in case of a scyphozoan P. noctiluca sting, vinegar application may be counterproductive, worsening the pain and discomfort of the stung area.

Preparation and Neutralization Efficacy of Novel Jellyfish Antivenoms against Cyanea nozakii Toxins

Jellyfish stings are a common issue globally, particularly in coastal areas in the summer. Victims can suffer pain, itching, swelling, shock, and even death. Usually, hot water, vinegar, or alumen is used to treat the normal symptoms of a jellyfish sting. However, a specific antivenom may be an effective treatment to deal with severe jellyfish stings. Cyanea nozakii often reach a diameter of 60 cm and are responsible for hundreds of thousands of stings per year in coastal Chinese waters. However, there has been no specific C. nozakii antivenom until now, and so the development of this antivenom is very important. Herein, we collected C. nozakii antisera from tentacle extract venom immunized rabbits and purified the immunoglobulin (IgG) fraction antivenom (AntiCnTXs). Subsequently, two complete procedures to produce a refined F(ab')₂ type of antivenom (F(ab')₂-AntiCnTXs) and Fab type of antivenom (Fab-AntiCnTXs) by multiple optimizations and purification were established. The neutralization efficacy of these three types of antivenoms was compared and analyzed in vitro and in vivo, and the results showed that all types of antibodies displayed some neutralization effect on the lethality of C. nozakii venom toxins, with the neutralization efficacy as follows: F(ab')₂-AntiCnTXs ≥ AntiCnTXs > Fab-AntiCnTXs. This study describes the preparation of novel C. nozakii jellyfish antivenom preparations towards the goal of developing a new, effective treatment for jellyfish stings.

Dermatological Progression of a Probable Box Jellyfish Sting

This case report describes the typical features of the dermatological progression of a patient stung by a (probable) box jellyfish. The purpose is to guide clinicians and patients to an understanding of what to expect after such a sting using the clinical narrative and unique sequential photographs of the injury. With knowledgeable consultation from experienced physicians and meticulous care, this envenomation healed without the need for skin grafting.

Millepora species (Fire Coral) Sting: A Case Report and Review of Recommended Management

Fire corals (Millepora spp) are the second most common reef-forming organisms and are frequently found in tropical and subtropical waters. Fire corals are not true corals but rather hydrozoans more closely related to jellyfish and sea nettles. Rigidly affixed to the reef and with a branching structure, each fire coral is a colony of numerous individual hydrozoans forming a collective symbiotic organism. It is common for divers to accidentally make contact with fire corals. Fire coral contact is characterized by the immediate onset of burning pain caused by venom discharge from numerous tiny nematocysts located externally on the creature. Treatment consists of saltwater irrigation of the wound, nematocyst removal, and supportive care of the associated symptoms of pain, dermatitis, and pruritus. Rarely, fire coral can cause systemic toxicity. We present a case report of a 30-y-old recreational diver who experienced a fire coral sting of her left anterior thigh and review the recommended prevention and management of fire coral stings.

Impact of Scyphozoan Venoms on Human Health and Current First Aid Options for Stings

Cnidaria include the most venomous animals of the world. Among Cnidaria, Scyphozoa (true jellyfish) are ubiquitous, abundant, and often come into accidental contact with humans and, therefore, represent a threat for public health and safety. The venom of Scyphozoa is a complex mixture of bioactive substances—including thermolabile enzymes such as phospholipases, metalloproteinases, and, possibly, pore-forming proteins—and is only partially characterized. Scyphozoan stings may lead to local and systemic reactions via toxic and immunological mechanisms; some of these reactions may represent a medical emergency. However, the adoption of safe and efficacious first aid measures for jellyfish stings is hampered by the diffusion of folk remedies, anecdotal reports, and lack of consensus in the scientific literature. Species-specific differences may hinder the identification of treatments that work for all stings. However, rinsing the sting site with vinegar (5% acetic acid) and the application of heat (hot pack/immersion in hot water) or lidocaine appear to be substantiated by evidence. Controlled clinical trials or reliable models of envenomation are warranted to confirm the efficacy and safety of these approaches and identify possible species-specific exceptions. Knowledge of the precise composition of Scyphozoa venom may open the way to molecule-oriented therapies in the future.

Cnidarian Jellyfish: Ecological Aspects, Nematocyst Isolation, and Treatment Methods of Sting

Cnidarians play an important role in ecosystem functioning, in the competition among species, and for possible utilization of several active compounds against cardiovascular, nervous, endocrine, immune, infective, and inflammatory disorders or having antitumoral properties, which have been extracted from these organisms. Nevertheless, notwithstanding these promising features, the main reason for which cnidarians are known is due to their venomousness as they have a serious impact on public health as well as in economy being able to affect some human activities. For this reason a preeminent subject of the research about cnidarians is the organization of proper systems and methods of care and treatment of stinging. This chapter aims to present the data about the morphological, ecological, toxicological, epidemiological, and therapeutic aspects regarding cnidarians with the purpose to summarize the existing knowledge and to stimulate future perspectives in the research on these organisms.

Evaluation of Cyanea capillata Sting Management Protocols Using Ex Vivo and In Vitro Envenomation Models

Lion's mane jellyfish (Cyanea capillata) stings cause severe pain and can lead to dangerous systemic effects, including Irukandji-like syndrome. As is the case for most cnidarian stings, recommended medical protocols in response to such stings lack rigorous scientific support. In this study, we sought to evaluate potential first aid care protocols using previously described envenomation models that allow for direct measurements of venom activity. We found that seawater rinsing, the most commonly recommended method of tentacle removal for this species, induced significant increases in venom delivery, while rinsing with vinegar or Sting No More® Spray did not. Post-sting temperature treatments affected sting severity, with 40 min of hot-pack treatment reducing lysis of sheep's blood (in agar plates), a direct representation of venom load, by over 90%. Ice pack treatment had no effect on sting severity. These results indicate that sting management protocols for Cyanea need to be revised immediately to discontinue rinsing with seawater and include the use of heat treatment.

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

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 tentacle cnidae discharge during a sting event using an ex vivo tissue model which elicits spontaneous stinging from live cnidarian tentacles. We then tested a variety of rinse solutions on both Atlantic and 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 recently developed Sting No More® Spray, were the most effective rinse solutions, as they irreversibly 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.