Case Report

Stonefish envenomation Abstract

As more Americans travel in greater numbers in search of

exotic destinations, they may encounter dangerous marine life that hide in reefs and shallow marine waters. In this case report, we describe a case of stonefish envenomation and provide a review of the literature on management and prevention.

As Americans travel abroad and engage in marine sports with increasing frequency, previously rare envenomations may become more common. Patients may present with acute or delayed sequelae of injury upon returning home. Many clinical presentations will benefit from specific treatments with which an emergency provider may be unfamiliar.

An otherwise healthy 27-year-old man was transported to a hospital by emergency medical services after suddenly developing severe pain in his left foot while walking on the surf at a local beach in Guam. The patient complained of severe distress due to pain described as constant, throbbing, and crushing with a sensation of numbness surrounding the painful area on the plantar aspect of his left foot.

Physical examination revealed redness along the bottom of the patient’s left foot, with bruising surrounding a puncture site in the center of the left heel. The affected area was immediately placed in a basin of hot water. The patient’s pain was unchanged by Intravenous morphine sulfate. An x-ray of the patient’s left heel was unremarkable and did not reveal any retained foreign body. Based on the patient’s history, physical examination findings, the severity of the patient’s pain, and the emergency provider’s knowledge of local fauna, a diagnosis of stonefish envenomation was made.

The patient received an additional dose of morphine, as well as methylprednisolone 125 mg IV, after which the pain was controlled. At no point did the patient note symptoms such as confusion, shortness of breath, chest pain, nor focal weakness or numbness, apart from the area surrounding the puncture site. Vital signs were normal throughout the visit. The patient was discharged home with prescriptions for prednisone, acetaminophen/oxycodone, and levofloxacin. discharge instructions included use of hot soaks, elevation, and criteria for returning to emergency department.

In any suspected envenomation, an emergency provider must combine a careful history, physical examination, and

knowledge of local fauna. Travel and exposures to increas- ingly diverse environs will undoubtedly lead to more numerous and exotic envenomations.

Stonefish (eg, Synanceia verrucosa, Synanceia hornium, and Synanceia nana) are members of the Synanceiidae family but have also been classified by some as part of the Scorpaenidae family (Fig. 1). Stonefish can be found in reefs and shallow marine waters of the Indian and Pacific oceans [1]. Local names include Rockfish, Goblinfish, Devilfish, Warty-ghoul, Dornorn, Sherovea, and “Nofu” (The Waiting One). These names reflect the stonefish’s spiny appearance and its tendency to burrow under sand or mud in shallow water to surprise small passing fish upon which it preys. Human envenomation typically occurs when an unsuspect- ing individual either jumps out of a boat into shallow water or wades into a reef and steps onto the spiny dorsal fins of a hidden stonefish [1]. In Guam, stonefish tend to have a sandy brown appearance and blend into the shore shallows.

The pain of envenomation is notoriously intense and immediate, increasing over the first 10 minutes after exposure. Swelling follows the pain and may be severe, spreading proximally from the injection site. Patients describe numbness in the center of the swollen area and severe pain at the edges. Affected area may become discolored with a bluish or blanched appearance. Although

Fig. 1 Stonefish (http://en.wikipedia.org/wiki/Image:Stone _ Fish _ at _AQWA_ SMC2006.jpg#filelinks, accessed December 19, 2007; with appreciation to Sean Mack, photographer).

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sensation and normal muscular functioning of the affected area may return, hypersensitivity and edema of the affected area may last for weeks. This may result in repeated visits to the emergency department or primary care physician for continuED management. Healing of puncture wounds is often delayed, and ulcerations may develop and persist for several months [1]. There are rare reported cases of mortality from paralysis of the chest muscles, heart failure, and/or cardiac arrest due to stonefish envenomation, possibly secondary to the systemic effects of increased capillary permeability and hypotension or even hysteria due to pain leading to drowning. However, morbidity and mortality are mainly because of local tissue necrosis and secondary infection [2-5].

After a patient is removed from danger of drowning or further envenomation, care should be focused on treating any systemic effects of envenomation. Laboratory studies have shown that stonefish poison has cardiovascular, neuromus- cular, and cytolytic properties [6,7]. The venom consists of a potent neurotoxin (trachynilysin), as well as a catecholamine cardiotoxin (cardioleputin) [7]. Antivenom is available from Australia’s CSL Limited but should be reserved for severe systemic cases because it presents a risk of severe adverse reaction such as anaphylactic shock or serum sickness [8].

Stonefish venom is heat labile, and immersion of the affected area in hot water should provide pain relief. The water should be as hot as can be tolerated without scalding (42?C- 45?C), and immersion should be continued until pain resolves, often for several hours, and repeated with return of pain. Along with hot water immersion, oral or parenteral opioid analgesics may be required to control the severe pain. In addition, some have advocated infusing lidocaine locally for additional pain control [9]. Because the envenomated area may be numb, inclusion of the unaffected limb in hot water bath may help to avoid burning the patient. Previous reports have suggested that hot water immersion may increase the risk of developing a severe secondary infection and recommend providing an antibiotic that covers marine organisms, especially Vibrio vulnificus, before or during hot soaks [3]. Antibiotic therapy is recommended for all puncture wounds of the hand and foot because of high Incidence of infection [2].

Any retained spines should be removed as early as possible because they may continue to envenomate and increase risk of secondary infection. Radiographs and ultrasound should be used to identify possible retained foreign bodies, and surgical exploration may be necessary. Elevation of the affected area should be done to reduce inflammation. All patients must be followed closely to ensure that they do not develop a severe infection.

Prevention of stonefish envenomation may be possible with the use of tough, thick-soled shoes in endemic areas (spines have been known to penetrate tennis shoes). A shuffling gait is also said to reduce risk of injury as it may alert a stonefish to one’s presence before stepping on its spiny dorsal fin [1].

Owen Prentice MD Department of Emergency Medicine Boston University School of Medicine

Boston, MA, USA

William G. Fernandez MD, MPH Department of Emergency Medicine Boston University School of Medicine

Boston, MA, USA Department of Emergency Medicine US Naval Hospital Guam

E-mail address: [email protected]

Todd J. Luyber MD Tracy L. McMonicle PA Department of Emergency Medicine US Naval Hospital Guam

Marc D. Simmons MD Department of Emergency Medicine Lawrence General Hospital Laurence, MA, USA

Department of Emergency Medicine US Naval Hospital Guam

doi:10.1016/j.ajem.2008.01.055

The views expressed in this work are those of the individuals, and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the U.S. Government.

References

1. Edmonds C. Dangerous marine creatures. Flagstaff (Ariz): Best Publishing Co; 1995.
2. Lee JY, Teoh LC, Leo SP. Stonefish envenomations of the hand-a local marine hazard: a series of eight cases and a review of the literature. Ann Acad Med Singapore 2004;33(4):515-20.
3. Tang WM, Fung KK, Cheng VC, et al. Rapidly progressive necrotising fasciitis following a stonefish sting: a report of two cases. J Orthop Surg 2006;14(1):67-70.
4. Dall GF, Barclay KL, Knight D. Severe sequelae after stonefish envenomation. Surgeon 2006;4(6).
5. Lyon RM. Stonefish poisoning. Wilderness Environ Med 2004;15: 284-8.
6. Church JE, Hodgson WC. The pharmacological activity of fish venoms.

Toxicon 2002;40:1083-93.

1. Chen D, Kini RM, Yuen R, Khoo HE. Haemolytic activity of stonustoxin from stonefish (Synanceja horrida) venom: pore formation and the role of cationic amino acid residues. Biochem J 1997;325: 685-91.
2. Stonefish antivenom [product information]. CSL Limited 45 Poplar Road, Parkville, Victoria 3052, Australia. Amended September 20, 2004
3. Atkinson PRT, Boyle A, Hartin D, McAuley D. Is hot water immersion an effective treatment for marine envenomation? Emerg Med J 2006;23: 503-8.