Stonefish envenomation of hand with impending compartment syndrome

Synanceia spp. is a genus of fish from the family Synanceiidae, the Stonefish, whose members are dangerous and even fatal to human. It is one of the most venomous fish currently known in the world [1]. They are found in the coastal regions of Indo-Pacific oceans as well as off the coast of Florida and in the Caribbean.

Stonefish has potent neurotoxins secreted from glands at the base of their needle-like dorsal fin spines, which stick up when disturbed or threatened. The name, “Stonefish”, derives from its ability to camouflage with a grey and mottled color similar to the color of a stone. They are often covered by a coat of slime to which algae adhere. This excellent camouflage and their habit of partially burying themselves in the sand, makes them difficult to detect and avoid. Many small fishes easily fall prey to its superior camouflage ability. Human too, may not notice them most of the time, and thus inadvertently touch or step on them, triggering a sting. When disturbed, the stonefish injects an amount of venom proportional to the amount of pressure applied to it. They have earned labels such as ‘the master of deceit’ and ‘devil-fish’ due to their unaesthetic appearance and toxic venom. Like other venomous animal venoms, stonefish venom exhibits hemorrhagic, hemolytic, and proteolytic enzymatic activity [2]. The stings will lead to excruciating pain and gross oedema of the affected limb.

In Malaysia and Singapore, stonefish stings are rare. There were only eight cases reported within year 2001 and 2003 [3].

Our patient is a thirty-year-old Burmese aquarium cleaner in Aquaria KLCC, who was accidentally stung on his right index finger by a stonefish during a cleaning work. He immediately suffered from intense burning pain over radial aspect of his right index finger. The sharp pain soon spread to his ipsilateral axilla. Rapid-onset gross swelling developed in the affected finger and within two hours, his entire right index finger and radial half of the hand were swollen and erythematous. There was no stonefish spine retained in the wound. Despite receiving regular analgesia in the form of fentanyl and morphine, he still suffered from intense pain over his index finger. Anti-tetanus injection, antihistamine and steroid were administered and the limb elevated in attempt to reduce the swelling. Intravenous antibiotics (amoxicillin/clavulanic acid and metronidazole) were also given.

Twelve hours later, the pain had progressively worsened again and swelling had spread to involve the dorsum and radial half of his right hand (Fig. 1). Blisters appeared on his right index finger and he had paraesthesia over the median nerve distribution over the affected hand. Sensation reduced over the tip of right index finger and oxygen saturation on pulse oximeter dropped to 89 %, which raised the fear of impending compartment syndrome associated with symptoms of acute carpal tunnel syndrome. Clinically, patient was afebrile with stable vital signs. Laboratory results, including a white blood cell count, haemoglobin level, clotting profile; renal (electrolytes) and liver function tests were all normal. No gas shadow was seen in the right hand plain radiograph. All Gram stains and subsequent cultures were negative. There was no specific anti-venom for stonefish available in National Poison Centre. Patient was treated with warm water immersion and elevation in between immersion. Swelling gradually subsided. Fasciotomy was not required as the patient had responded well with the conservative management. His right hand swelling and circulation improved gradually. There was no local skin necrosis. Patient was discharged well with good recovery from pain and numbness after 4 days of hospital stay. There was no associated neurogenic or vascular sequelae noted during subsequent follow up. He had a full motion in his fingers and wrists joints at six weeks follow up.

The stonefish is an environmental hazard to the unwary swimmer, angler, aquarium cleaner, and chefs. Their unparalleled camouflage ability makes them virtually undetectable and unavoidable. Envenomation can lead to unwanted local morbidity, excruciating pain, gross oedema of the affected limb, and severe systemic reactions have been reported. In majority, most of the cases do not result in protracted morbidity and it only requires prompt recognition, early pre-hospital care, and supportive management for symptomatic relief. We figured out that conservative management with short period of hot water immersion at temperature below 45° is generally safe and it helps to prevent unnecessary surgical intervention.