There is a study in today’s New England Journal of Medicine on an anti-venom for the bark scorpion Centruroides sculpturatus.

Antivenom for the bark scorpion is a single sentence in our WFR curriculum “There is an antivenom available for serious envenomations.”   It's need is rare.  It's expensive, hard to store and well beyond the field skills of a WFR to administer.  Our focus is on recognizing the signs and symptoms of an envenomation warranting evacuation. 

Apparently, 8,000 Arizona residents are stung by scorpions each year.   Most adults recover without needing medical treatment and only experiencing the local reaction.  Annually about 200 children experience severe neurotoxic symptoms including trouble breathing due to abundant respiratory secretions, weak and erratic ventilatory effort and  pulmonary edema.

Bark scorpion antivenon is available in Mexico, but since 1999 has not been manufactured in the US.  Physicians were wary of using it due to side effects and allergic responses. 

This paper is a report of a small clinical trial (15 patients) of young children with serious neurotoxic s/s after a sting by a bark scorpion.  Most patients given the investigational drug (Anascorp) recovered within two hours, while children given a placebo had symptoms that lasted four hours or more and required heavy sedation and hospitalization.

The drug is a scorpion-specific F(ab′) antivenom  produced with the use of scorpions from several southern Mexican species in the same genus as the Arizona variety.

The study is small and can not fully evaluate safety, but it's promising.

The paper should be available free at http://content.nejm.org/cgi/content/full/360/20/2090.

Take care

Tod

Antivenom for Critically Ill Children with Neurotoxicity from Scorpion Stings.  n engl j med 360;20 nejm.org may 14, 2009