32 year-old man presents with a spider bite

Wound care, immobilization, tetanus prophylaxis, analgesics, and antipyretics

Key Point:

Optimal therapy for brown recluse spider bites is extremely controversial.

Explanation:

Many therapies have been proposed; however, few--with the exception of local wound care--have proven to be beneficial. Some may even be harmful. At this time, the only therapy that is clearly beneficial is local wound care and symptom control.

Early excision and intralesional injection of corticosteroids are not advised. These lesions undergo considerable transformation over days to weeks following envenomation. Excising the local wound at this time does not preclude expansion of the wound or the associated and considerable morbidity. Intralesional steroids may actually promote wound expansion by spreading the venom. When administered early, dapsone may inhibit local infiltration of the wound by leukocytes and, therefore, decrease size; however, numerous studies have not demonstrated any clear benefit to dapsone compared with other therapies. Dapsone is also associated with the development of hepatitis, hemolysis, and methemoglobinemia. Animal studies have mixed results about the benefits of hyperbaric oxygen therapy for reducing the final size of the wound.

Reference:

Otten EJ. Venomous animal injuries (chapter 55). In: Walls R, et al. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed., 2018:698-714.