Antivenin-related serum sickness.

Serum sickness is a type III hypersensitivity reaction that occurs due to the deposition of excessive circulating immune complexes in patients treated with foreign proteins or haptens. Serum sickness induced by antivenin for snakebites has been frequently reported in the USA, but not in Taiwan. This difference may be due to the efficacy and dosage of antivenins administered to treat snakebites in Taiwan. We report a case presenting with serum sickness after receiving a total of 20 vials of polyvalent antivenin therapy for the treatment of snakebite. A 59-year-old male suffered from fever, headaches, polyarthritis, and diffused skin rash approximately 10 days after administration of the antivenin. The large dose of antivenin administered in this case might have been the cause of the development of serum sickness. Physicians should be aware of the potential for serum sickness in cases of large-dose antivenin use.