Rapidly progressive necrotising fasciitis following a stonefish sting: a report of two cases

Journal of Orthopaedic Surgery, Apr 2006 by Tang, W M, Fung, K K, Cheng, V C, Lucke, L

ABSTRACT

Two patients developed rapidly progressive necrotising fasciitis after being stung by a stonefish. Both were given a hot-water bath for pain relief. The hot water may have accelerated bacterial growth and the consequent development of necrotising fasciitis. Vibrio vulnificus was cultured from one patient. It is recommended that patients should receive high dose of oral and intravenous antibiotic prophylaxis for vibrio prevention. Antibiotics should be given before or during, not after, a hot-water bath, and the patient's condition should be monitored closely.

Key words: bites and stings; fasciitis, necrotizing; streptococcal infections

INTRODUCTION

Stonefish (Synanceja horrida), a member of the family Scorpaenidae, is considered the most venomous of fish.1-3 It lives in the shallow waters of the Indo-Pacific region. Each stonefish has 13 dorsal spines, and each spine is connected to a pair of venomous glands that are capable of producing a very potent but heat-labile venom.1-3 The venom is myotoxic, neurotoxic, vasopermeable, and cardiotoxic.4 The craggy and warty surface of the fish provides excellent camouflage against the surrounding mud. Swimmers or divers are usually injured by accidentally treading on the fish. The pressure of the victim's body weight thrusts the dorsal spines into the skin and facilitates venom injection.3 In some parts of Asia, such as Hong Kong, stonefish is considered a great delicacy and thus poses an occupational hazard for those working in the fishing or food industry.5 Although the injury is usually self-limiting with no significant consequences, victims experience severe pain around the punctured wound.1-3 Treatment is mainly supportive: because of the heat-labile nature of the toxin, severe pain can be effectively controlled by immersing the affected extremity in hot water.1-5 This established treatment may nonetheless have accelerated the development of necrotising fasciitis.

CASE REPORTS

Case 1

In November 2002, a 57-year-old healthy, non-alcoholic, and non-diabetic Chinese fisherwoman presented with a painful swollen left leg after dropping a stonefish on her left foot. The dorsal spines pierced through her canvas shoe and injured the dorsum of the left foot. She experienced immediate severe pain in the left foot and presented to a private physician who suggested immersing the foot in hot water for pain relief. No antibiotics were administered prior to immersion. The pain was promptly relieved, and the patient was prescribed a one-week course of oral ofloxacin.

On the same night, she was rushed to the emergency room of the Queen Mary Hospital, Hong Kong with a temperature of 38.5�C, blood pressure of 140/80 mm Hg, and pulse rate of 100 beats per minute. The skin of the left foot to the mid-calf appeared dusky and was very tender to light touch. The swelling had spread from the left foot to the upper calf in a few hours. The patient's clotting profiles, electrolytes, renal and liver functions were all normal. Haematology revealed haemoglobin level of 136 g/l, leukocyte count of 12.3 �10^sup 9^/l, and platelet count of 300 �10^sup 9^/l. Subcutaneous aspiration at the calf revealed some turbid fluid. Urgent fasciotomy and exploration showed subcutaneous oedema with early fat and fascia necrosis typical of necrotising fasciitis.6 The muscle beneath the deep fascia was normal. Vibrio vulnificus was cultured from the subcutaneous aspirate, fat, and fascial tissues obtained from fasciotomy. Histological examination confirmed the diagnosis of necrotising fasciitis. The patient was treated with intravenous amoxicillin/clavulanate and ciprofloxacin for one week. The fasciotomy wound was closed with skin grafting 3 weeks later. She returned to work 8 weeks later.

Case 2

In February 2003, a 27-year-old healthy, non-nlcoholic, and non-diabetic Chinese chef of a seafood restaurant was admitted to hospital with pain and swelling of the right hand extending up to the mid-forearm. The patient had been pricked by the dorsal spines of a stonefish 4 hours earlier on the volar aspect of the base of the right ring finger. Immersion of the right hand and forearm in hot water for 90 minutes resulted in considerable, though incomplete, relief of pain and swelling. No antibiotic was given before the hot-water bath. Two hours later, while the patient was still in the observation room, he noted a return of the swelling and severe aching pain in his right hand. He was commenced on intravenous amoxicillin/clavulanate and ciprofloxacin and transferred to the Queen Mary Hospital, Hong Kong.

The patient was afebrile with a blood pressure of 120/80 mm Hg and pulse rate of 80 beats per minute. The swelling was more prominent over the ring finger (Fig. 2). He was unable to close his hand because of severe pain that was further aggravated by passive stretching of the fingers. His clotting profiles, electrolytes, renal and liver functions were all normal. Full blood count analysis revealed haemoglobin level of 140 g/l, leukocyte count of 10.8 �10^sup 9^/l, and platelet count of 354 �10^sup 9^/l. Urgent exploration and fasciotomy revealed subcutaneous dish-water pus and dull-whitish fascia6 extending to the wrist. No pus was found in the flexor tendon sheath of the right ring finger, and the flexor tendon appeared unaffected. Microscopy of the dish-water pus revealed curveshaped gram-negative bacteria but cultures of the pus and soft tissues were negative. The diagnosis of necrotising fasciitis was confirmed by histology. Antibiotic therapy was continued and the wound was closed 5 days later. The patient returned to work after 6 weeks of physiotherapy.