Suspected stonefish envenomation in Queensland over eight years: a retrospective series

Introduction: Stonefish envenomation results in localized severe pain and swelling and systemic features, including vomiting, arrhythmia, pulmonary oedema, and possibly death. There are limited data regarding the effectiveness of the available antivenom. The aim of this series is to characterize presentations of patients with suspected stonefish envenomation and investigate treatment, including antivenom.

Methods: This is a retrospective observational series of suspected stonefish envenomation as reported to the Queensland Poisons Information Centre or Princess Alexandra Hospital Clinical Toxicology Unit from July 2015 to January 2023. Patients were identified through the databases held by both the Centre and Unit, and data on clinical features and investigations were collected from the patient's electronic medical record.

Results: There were 87 suspected stonefish envenomations from July 2015 to January 2023. The median age was 26 (range: 5-69) years, and 69 (79 per cent) patients were male. Pain was reported in 85 (98 per cent) with a median peak pain score of 10 (range 4-12; three rated their pain greater than 10/10). A clear wound was documented in 64 (74 per cent), with local swelling in 63 (72 per cent). A foreign body was retained in eight (9 per cent) presentations. Systemic symptoms were rare, with vomiting in four (5 per cent) and dizziness in two (2 per cent) presentations. There were no instances of hypotension, arrhythmia, or pulmonary oedema. Hot water was administered in 72 (83 per cent) presentations. Oral analgesia was given in 55 (63 per cent). Parenteral analgesia was given in 53 (61 per cent), most commonly opioids. Local anaesthetic block was performed in 19 presentations (22 per cent), with effectiveness documented in 16/19 (84 per cent). Five patients received antivenom for intractable pain, and all received subsequent parenteral analgesia or local anaesthetic block.

Conclusions: Stonefish envenomation is characterized by severe pain. Systemic symptoms were rare and not severe in this series. Local anaesthetic block appeared to be the most effective intervention for severe pain when performed. Antivenom appeared to be ineffective in managing pain.