Laboratory Studies
Wound cultures and Gram stain may provide valuable information for local wounds.
If signs of systemic toxicity are present, monitor the patient for evidence of hemolysis, renal failure, and coagulopathy.
If treatment with dapsone is being considered, obtain a glucose-6-phosphate dehydrogenase (G-6-PD) level before treatment.
Other Tests
Several groups are currently developing laboratory methods of detecting brown recluse venom or venom components in tissue around the site of the bite. [10] One study suggests that exposure of red cells to brown recluse venom reduces their levels of glycophorin A; measurement of glycophorin A by flow cytometry may help identify exposed patients. [1] Once the technology to identify this venom in patients becomes readily available to the clinician, the ability to study this envenomation will burgeon.
Procedures
Conservative local debridement of necrotic lesions may be performed once the wound margins have been defined. Wide excision is disabling, disfiguring, and seldom indicated.
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Classic finding of a vesicle with surrounding erythema at 24 hours following brown recluse envenomation. Photo by Thomas Arnold, MD.
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Illustration of a brown recluse spider with the fiddle displayed prominently on its dorsum.
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Spider envenomations, brown recluse. Envenomation site on inner thigh untreated at 1 week. Photo by Thomas Arnold, MD.
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Typical appearance of a male brown recluse spider. Photo contributed by Michael Cardwell, Victorville, Calif.
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Female brown recluse with size scale. Photo contributed by Michael Cardwell, Victorville, Calif.
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Spider envenomations, brown recluse. Close-up image of dorsal violin-shaped pattern. Photo contributed by Michael Cardwell, Victorville, Calif.
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Spider bite, brown recluse. Within an hour, the bite area swelled to the size of a quarter. The area turned blue and dark red by the evening of the first day, exceeding the boundaries of a circle drawn around the area of initial swelling by the patient's physician. Courtesy of Dale Losher.
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Spider bite, brown recluse. The third day after the bite. The skin continues to die. Courtesy of Dale Losher.
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Spider bite, brown recluse. Another view of the wound 3 days after the bite. Courtesy of Dale Losher.
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Spider bite, brown recluse. Nine days after the bite. The patient endured 8 days with an open wound to drain the spider's toxins and needed multiple doses of intravenous antibiotics and pain medication. Courtesy of Dale Losher.
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Spider bite, brown recluse. Eleven days after the bite. A 5-inch wide area of dead tissue was excised, necessitating skin grafting. Courtesy of Dale Losher.
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Spider bite, brown recluse. Waiting to see skin graft results 38 days after the bite. Courtesy of Dale Losher.
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Spider bite, brown recluse. Skin graft results 38 days after the bite. Courtesy of Dale Losher.
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Spider bite, brown recluse. View of healed wound approximately 10 months after bite. Courtesy of Dale Losher.
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Dermonecrotic arachnidism represents a local cutaneous injury with tissue loss and necrosis.
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Brown recluse spider. Courtesy of US Centers for Disease Control and Prevention.
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Brown recluse spider. Courtesy of US Centers for Disease Control and Prevention.
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Complete distribution range of wild and domestic Loxosceles reclusa (brown recluse spider). Courtesy of Wikimedia Commons (By ReliefUSA_map.gif: Public domain, U.S. government derivative work: Bob the Wikipedian).
