The clinical response to stings of scorpions native to our country is generally mild. The indications for use of its antivenin, a horse serum-derived product, are unclear. Allergic reactions secondary to administration of scorpion antivenin may develop. A patient 28-year old male presented to our emergency department after a scorpion sting. A total of 2 mL of scorpion antivenin was administered to the patient: 1 mL intramuscularly and 1 mL locally around the sting site. Erythematous urticariall wheals developed on the whole abdominal wall skin within 30 minutes. Phenyramine maleate 50 mg IV was administered. The urticarial lesions recovered within 30 minutes after the administration of the antihistamine. The patient was discharged without further complication after an additional 12 hours of observation. Due to the risk of the development of anaphylactic reactions, drugs and equipment used in the treatment of anaphylaxis must be ready before giving antivenins.
Keywords: Antivenins, scorpions, urticaria