Abstract
Box jellyfish are highly venomous and numerous possible treatments for envenomation have already been reported in the published literature. The hand of a 55-year-old scuba diver was stung in the Gulf of Guinea resulting in two crops of coalescing vesicles with intense pain and lymphadenopathy. Traditional therapies such as hot water, cold packs and acetic acid were ineffective. Symptoms were rapidly relieved after the application of a lemon-oil emulsion balm. Treatments for jellyfish envenomation generally aim to either denature the jellyfish venom or prevent the discharge of the venom. Lemon-oil emulsion therapy has not yet been reported in the published literature but may be an economical and novel treatment for box jellyfish envenomation.
Introduction
Jellyfish are not fish but a form of gelatinous zooplankton. They may have highly toxic venom, especially those known as box jellyfish (class Cubozoa) including Chironex fleckeri, Carukia barnesi, Alatina alata and Chiropsalmus quadrumanus. Contact with the tentacles releases a multitude of microscopic harpoon-like structures called nematocysts which release venom into the victim. Jellyfish stings cause a wide spectrum of symptoms in humans ranging from mild pain and pruritis to excruciating pain with necrosis and scarring. Rare symptoms include cardiovascular failure, pulmonary oedema, nausea/vomiting and anaphylaxis.1,2 Stings from the most toxic box jellyfish species, including C. fleckeri, can be fatal within minutes. 1 No consensus exists on the most efficacious treatments. Anecdotal remedies in the published literature include topical application of urine, vinegar, ammonia, meat tenderizer enzymes, sodium bicarbonate, boric acid, lemon juice, fresh water, steroid cream, alcohol, cold packs, papaya, palm oil and hydrogen.
Case history
A 55-year-old male, scuba diving near the island nation of São Tomé about 180 miles west of Africa, was stung in two locations on the left hand by a box jellyfish. He was in approximately 20 ft of water and reported experiencing a sudden-onset sharp and burning pain of 9/10 severity at the site of tentacle entanglement. During his ascent to the surface the phosphorescent firing of nematocysts was visible. Immediately upon surfacing he urinated on his hand without effect. The immersion of the hand in hot water and lemon juice intensified the pain further. Cold packs offered minimal relief.
The initial skin lesions were two 1.5 × 2.5cm erythematous plaques followed by vesicle formation, which coalesced into flaccid blisters (Figure 1). After 24 h the diver's hand and forearm were warm and oedematous. Axillary lymphadenopathy was present without fever or chills. Local dive masters who were familiar with treatments for box jellyfish envenomation recommended the application of a palm oil and lemon juice emulsion. 30 h after the event the diver applied the recommended emulsion and experienced significant pain relief within the first 20 minutes. At 6 weeks follow-up, the wounds and lymphadenopathy had resolved completely.
Evolution of box jellyfish envenomation sites: days 2(A), 7(B) and 14(C).
Discussion
In general, there have been two approaches to the treatment of jellyfish stings. One approach has focused on preventing the discharge of nematocysts once a sting has occurred. In various Cnidarian species the discharge of nematocysts has been induced by the application of acetic acid, ammonia, ethanol, sodium hypochlorite and sodium bicarbonate. Consequently, common home remedies such as vinegar, lemon juice, and urine may actually cause nematocysts remaining on the skin to discharge, thereby worsening the injury. 3 Avoiding these so-called remedies may be beneficial. A second approach has focused on inactivating the venom. The popularity of many home remedies reflects the theory that lowering pH denatures venom protein.
These two conflicting approaches to treatment may account for the confusion in the literature on the clinical efficacy of different treatments. Further complicating matters, the venoms of jellyfish are known to be species-specific and, therefore different agents may have different effects. For example, the application of acetic acid has been reported to help relieve pain in stings caused by the boxfish species C. fleckeri but exacerbate lesions caused by the species Chrysaora quinquecirrha.3,4 Hot water seems to be an effective treatment for stings from the species C. alata but there is little data to support its efficacy in other species. 5
Conclusion
Research investigating the possible efficacy of oil and other hydrophobic emulsions in the treatment of box jellyfish envenomation is sparse. However, this was the only treatment which provided relief for the victim. Further research is needed on the use of hydrophobic emulsions in the treatment of box jellyfish envenomations.
Footnotes
Declaration of conflicting interests
None declared.
Funding
This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.