Scorpion envenomation: does administration of antivenom alter outcome?

Clinical scenario

A woman presents to the emergency department after being stung by a scorpion, which was hiding in a bunch of bananas in her local supermarket. She is in great pain and feels sick. You wonder whether she should be given an antivenom.

Three part question

After [scorpion envenomation] does the [use of antivenom] [improve outcome]?

Search strategy

Medline 1966-11/04 using the OVID interface. [exp Scorpions OR scorpion.mp OR exp Scorpion Venoms OR scorpion venom.mp OR scorpionism.mp] AND [envenoming.mp OR envenomation.mp] AND [exp Antivenins OR antivenom.mp OR exp Immunization, Passive OR serotherapy.mp OR exp Immunoglobulins, Fab] LIMIT to human AND English language.

Search outcome

Altogether, 69 papers were found, only four of which presented any comparison of treatment with or without scorpion antivenom.

Comment(s)

While there are many case series and retrospective reviews in the literature suggesting that scorpion antivenom is safe and effective, there is only one randomised controlled trial of this treatment, which showed no improvement in symptoms or in preventing symptom progression. There was no difference in hospital admission rate or duration of stay, and no difference in mortality. Two other studies had similar results. Only Ghalim et al found any clinical improvement and this was mainly for local symptoms. Deaths in adults are very rare, and most patients have only local or mild systemic symptoms, which resolve with symptomatic treatment.

CLINICAL BOTTOM LINE

In an adult who has been stung by a scorpion, there is very little evidence that giving antivenom will improve clinical outcome.