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Scorpion envenomation: Does administration of antivenom alter outcome?

Three Part Question

After [scorpion envenomation] does the [use of antivenom] [improve 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 a lot of pain and feels sick. You wonder whether she should be given an antivenom.

Search Strategy

Medline 1966-11/04 using the OVID interface
[exp Scorpions OR OR (exp Scorpion Venoms OR scorpion OR] AND [ OR] AND [exp Antivenins OR OR exp Immunization, Passive OR 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.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Sofer S et al,
Children admitted to PICU after scorpion envenomation. Comparison of 52 children given antivenom between 10 July 1885 and 1 July 1989 and 52 children treated without antivenom between 1 July 1989 and Dec 31 1992.CohortDuration of PICU stayNo significant differenceHistorical comparison. Children treated without antivenom may have benefitted from improved supportive care.
Duration of hospital stayNo significant difference
Full recovery49 in antivenom group, 52 in control group
Death2 in antivenom group, 0 in control group
Belghith M et al,
Patients participating in a study on the efficacy of high-dose hydrocortisone after scorpion sting. Matched-pair comparison of 135 patients given scorpion antivenom in addition to their trial medication.CohortClinical improvement50% of antivenom group, 64% control groupRetrospective review of patients recruited into another trial. Results not stratified according to hydrocortisone treatment.
Prevention of progression of symptoms13% antivenom group, 10% control group
Duration of hospital stayNo significant difference
Death1 in control group
Abroug F et al,
825 consecutive patients aged 10 or older presenting to a non-teaching hospital emergency departmentRandomised placebo-controlled trial of intravenous scorpion antivenomClinical improvement55% antivenom group, 66% control groupTrial found to be underpowered to show any difference in mortality as mortality was so low.
Prevention of symptom progression94% in antivenom group, 96% in control group
Hospital admission13% in antivenom group, 9% in control group
Duration of hospital stayNo significant difference
Death1 in each group
Ghalim N et al,
275 patients with scorpion envenomation, 179 of whom were treated with antivenom (IM, SC or both routes)Prospective cohortEffectiveness of antivenom according to sting admission intervalAntivenom more effective if sting admission interval < 1 hour90% of patients had only grade I envenomation. No evidence that patients were randomised or that treatment was blinded. Statistical analysis of clinical features unclear. There appears to be a 50% baseline difference in incidence of systemic symptoms between the antivenom and no antivenom groups, in favour of the antivenom group.
Local symptomsGreater reduction in local pain and burning reported with antivenom
Systemic symptomsLower incidence of systemic symptoms in the antivenom group


While there are many case series and retrospective reviews in the literature suggesting that scorpion antivenom is safe and effective, there is only one RCT of this treatment. This 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.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.


  1. Sofer S, Shahak E, Gueron M. Scorpion envenomation and antivenom therapy. J Pediatr 1994;124(6):973-8.
  2. Belghith M, Boussarsar M, Haguiga H, et al. Efficacy of serotherapy in scorpion sting: a matched-pair study. J Toxicol Clin Toxicol 1999;37(1):51-7.
  3. Abroug F, Elatrous S, Nouira S, et al. Serotherapy in scorpion envenomation: a randomised controlled trial. Lancet 1999;354(9182):906-9.
  4. Ghalim N, El-Hafny B, Sebti F, et al. Scorpion envenomation and serotherapy in Morocco. Am J Trop Med Hyg 2000;62(2):277-83.