A Trial of Equine F (ab')2 Antivenom for Treatment of Scorpion Envenomation in Morocco

In an effort to shorten hospital stay and to further decrease mortality, a new antivenom has been developed. This antivenom is a third generation F(ab')2 "fabotherapeutic" agent.It is administered intravenously which should lead to rapid neutralization of circulating venom. This study will demonstrate whether or not use of the new antivenom in children receiving standardized supportive care leads to resolution of the syndrome within 4 hours of treatment.The onset of clinical symptoms following a scorpion envenomation is usually within 5 to 30 minutes following the sting.

Established a classification of the patient status to differentiate a simple scorpion sting from a severe envenomation. A simple sting (class I) is characterized by signs that are local only: pain at the inoculation point, redness, edema, and numbness.

A class II envenomation is characterized by the presence of some systemic signs: hypothermia, hyperthermia, chills, nausea, abdominal pain and diarrhea. Being 15 years old or younger or the presence of priapism, vomiting, sweating, or a body temperature greater than 39°C are factors predictive of severity.

A severe envenomation (class III) is characterized by cardiovascular failure, often leading to death; respiratory failure related to the cardiac failure; and neurologic failure due to hypoxia.

Inclusion criteria

• Male or female 6 months to 15 years
• Class II B or III scorpion envenomation
• Presenting within 5 hours of sting
• Informed consent read and signed by parent or legal guardian

Exclusion criteria

• Unable to provide informed consent
• Prior use of antivenom for this envenomation
• Allergy to horse serum
• Pregnant or breast-feeding
• Patients with underlying condition mimicking symptoms of scorpion envenomation (congenital heart disease, chronic oxygen therapy, etcetera)