19 April, 2017

What is the best treatment for scorpion envenomations?


Scorpions are still a significant cause for mortality, especially in developing countries. The are several treatment strategies available for serious scorpion stings. Some involves the use of anti-venom, while others are based on symptomatic treatment. Studies so far has shown that one treatment strategy works for some species, but are less effective for others.

Rodrigo and Gnanathasan have recently published a systematic review on scorpion envenomations trying to find the best evidence available for the efficiency of the different treatment strategies used against serious scorpion envenomation around the world.

The main conclusion is that the polyvalent antivenom against Centruroides sp. in USA/Mexico and the monovalent antivenom against Hottentotta tamulus in India are effective for rapid resolution of symptoms. Prazosin is useful as an add-on therapy for H. tamulus stings. I recommend reading the article for further details.

Abstract:
Background: Scorpion stings cause an estimated 3000 deaths per annum worldwide. We conducted a systematic review of all controlled clinical trials related to scorpion sting management.
Methods: We searched PubMed, EMBASE, Scopus, Web of Science and CINAHL and included controlled prospective clinical trials (randomized or non-randomized). The following interventions were assessed: adults and children with scorpion stings treated with (a) steroids vs. placebo, (b) different methods of pain relief, (c) antivenom vs. supportive treatment, (d) prazosin vs. supportive treatment, (e) antivenom vs. prazosin and (f) antivenom plus prazosin vs. prazosin alone. When trials had comparative outcomes, they were combined in a meta-analysis. Data was analysed with Review Manager 5. Dichotomous data were compared with relative risk (RR), and continuous data were compared with mean differences using a fixed effect model. There is no PROSPERO registration number for this study.
Results: Antivenom against Centruroides sp. are effective in reversing the clinical syndrome faster than no antivenom treatment in children (RR, 0.02; 95% CI, 0.01 to 0.06; 322 participants; three trials). Antivenom (against Mesobuthus tamulus) and prazosin combination is better than prazosin alone for faster resolution of symptoms (mean difference, −12.59 h; 95% CI, −14.01 to −11.17; 173 participants; three trials).
Conclusions: The polyvalent antivenom against Centruroides sp. in USA/Mexico and the monovalent antivenom against M. tamulus in India are effective for rapid resolution of symptoms. Prazosin is useful as an add-on therapy for M. tamulus stings.


Reference:
Rodrigo C, Gnanathasan A. Management of scorpion envenoming: a systematic review and meta-analysis of controlled clinical trials. Systematic Reviews. 2017;6(1):74. [Open Access]

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