Correspondence
Loxoscelism
N Engl J Med 1998; 339:1944-1946December 24, 1998
- Article
To the Editor:
Masters (Aug. 6 issue)1 provides a fascinating pictorial account of the progression of a lesion caused by the bite of a brown recluse spider, from the initial stages to healing. He reported that the patient was treated with dapsone. Dapsone, long used to reduce inflammation induced in treating leprosy, has been recommended for bites by brown recluse spiders because neutrophil infiltration is necessary for the development of necrotic lesions. Several studies have indicated that dapsone is an effective treatment for bites by brown recluse spiders.2-4 In my own work, I regularly discuss dapsone as a treatment option with physicians, and I cite its apparent efficacy in my textbook for physicians. However, it has come to my attention that a relatively recent, randomized, blinded, controlled study in rabbits failed to show any benefit from the use of dapsone.5 The authors concluded, “Given the negative result in this study with adequate power to detect meaningful treatment benefits, we cannot recommend hyperbaric oxygen, dapsone, or cyproheptadine in the treatment of Loxosceles envenomation.” Granted, their study involved the use of venom from Loxosceles deserta (not venom from the true brown recluse spider, L. reclusa) and New Zealand white rabbits (not humans), but the results should nonetheless make us reexamine exactly what we do and do not know about the benefits of dapsone.
5 ReferencesJerome Goddard, Ph.D.
Mississippi Department of Health, Jackson, MS 392151
Masters EJ . Loxoscelism. N Engl J Med 1998;339:379-379
Full Text | Web of Science | Medline2
King LE Jr ,Rees RS . Dapsone treatment of a brown recluse bite. JAMA 1983;250:648-648
CrossRef | Web of Science | Medline3
Rees R ,Campbell D ,Rieger E ,King LE . The diagnosis and treatment of brown recluse spider bites. Ann Emerg Med 1987;16:945-949
CrossRef | Web of Science | Medline4
Rees RS ,Altenbern DP ,Lynch JB ,King LE Jr . Brown recluse spider bites: a comparison of early surgical excision versus dapsone and delayed surgical excision. Ann Surg 1985;202:659-663
CrossRef | Web of Science | Medline5
Phillips S ,Kohn M ,Baker D , et al. Therapy of brown spider envenomation: a controlled trial of hyperbaric oxygen, dapsone, and cyproheptadine. Ann Emerg Med 1995;25:363-368
CrossRef | Web of Science | Medline
To the Editor:
Masters has beautifully photographed the evolution of the lesion caused by the bite of the brown recluse spider. This lesion can be abrogated by the use of corticosteroids if they are given within 48 hours. The diagnosis is easily made (without the spider), particularly in an area where the spider is endemic, because of the large, unusually painful, mottled lesion of patriotic colors. (It is definitely not a mosquito bite.) Investment in corticosteroids beats hospitalization and in some instances skin grafting or 67 days to healing, but again, early treatment is essential.
Hendrick B. Barner, M.D.
Barnes–Jewish Hospital, St. Louis, MO 63110To the Editor:
In the clinical images of loxoscelism, Panel E shows a sizable, cleanly granulating wound. Had skin grafting been used, the wound would have closed in a matter of days, obviating the prolonged, incomplete healing shown in Panel F.
The concept of converting an open wound to a closed wound by the simple expedient of applying a skin graft should not be forgotten. This is a procedure that can be performed with local anesthesia on an ambulatory basis.
Arthur G. Ship, M.D.
Albert Einstein College of Medicine, New York, NY 10461Author/Editor Response
The author and two colleagues reply:
To the Editor: As the treating physician and consultants, we are responding to the questions Drs. Ship, Barner, and Goddard raise about the treatment of a bite by a brown recluse spider.
Our experience in an area where brown recluse spiders are endemic indicates that dapsone therapy is the most suitable and leads to a satisfactory resolution. We agree that delaying surgical excision, avoiding the use of corticosteroids, and using dapsone to inhibit neutrophil-mediated tissue injury in cases of severe lesions caused by brown recluse spiders is controversial.
Dr. Ship recommends using skin grafts to hasten healing, but letting serious skin ulcers induced by the bites of brown recluse spiders resolve without surgery leads to better clinical outcomes. Immediate surgery or grafting, especially of the hand, is not recommended.1,2 Early surgical intervention increases tissue levels of acute-phase reactants that activate venom from the brown recluse spider, prolonging tissue injury and partly accounting for skin-graft rejections, poor functional and cosmetic results, and chronic ulcers. Severe lesions may not heal for more than 20 weeks and may become pyoderma gangrenosum–like lesions.3
Dr. Barner advocates early corticosteroid therapy. Laboratory and clinical studies show that corticosteroids are not effective.1,3 Systemic corticosteroids may prevent renal damage due to venom-induced hemolysis in children.2
Dr. Goddard questions the use of dapsone on the basis of a study in rabbits. In this study, there were no histologic analyses of lesional or nonlesional skin and no comparison with an effective therapy (brown recluse spider antivenom) or an ineffective therapy (systemic and intralesional corticosteroids). Studies in rabbits are not truly comparable to studies in humans since chronic ulcerations do not develop in rabbits and venom-induced lesions heal much faster in rabbits than in humans. However, differences between species do not explain why dapsone alone or in combination with brown recluse spider antivenom decreased histologically documented venom-induced damage in rabbits.4
Current therapy for severe, documented bites by brown recluse spiders is based on pathophysiology. In vivo studies have shown that neutrophil depletion ameliorates venom-induced tissue injury,2,5 as does dapsone alone or in combination with brown recluse spider antivenom.4 These results show that neutrophils are critical. In vitro studies have shown that venom from the brown recluse spider induces platelet aggregation that is dependent on acute-phase reactants (C-reactive protein and serum amyloid protein), dysregulated endothelial-cell–dependent activation of adherent neutrophils trapped within capillaries,6 and dapsone-inhibitable release of neutrophil granules within affected capillaries.6
Other treatment options, with variable and frequently disappointing results, include excision, colchicine, electric shock, hyperbaric oxygen, and nitroglycerin ointment.2 Since 90 percent of bites by brown recluse spiders are not accompanied by severe complications, in the case of a nonsevere lesion thought to be caused by the bite of a brown recluse spider, symptomatic therapy with rest, ice, compression, and elevation is indicated. Such an approach is prudent, since there is no readily available diagnostic test for bites by brown recluse spiders, and such bites may be misdiagnosed and treated inappropriately in areas where brown recluse spiders are not endemic.2
6 ReferencesEdwin Masters, M.D.
Regional Primary Care, Cape Girardeau, MO 63703Hunter Sams, M.D.
Lloyd King, Jr., M.D., Ph.D.
Vanderbilt Medical School, Nashville, TN 37212-12261
Rees RS ,Altenbern DP ,Lynch JB ,King LE Jr . Brown recluse spider bites: a comparison of early surgical excision versus dapsone and delayed surgical excision. Ann Surg 1985;202:659-663
CrossRef | Web of Science | Medline2
Wilson DC ,King LE Jr . Spiders and spider bites. Dermatol Clin 1990;8:277-286
Web of Science | Medline3
Rees RS ,Fields JP ,King LE Jr . Do brown recluse spider bites induce pyoderma gangrenosum? South Med J 1985;78:283-287
CrossRef | Web of Science | Medline4
Cole HP III ,Wesley RE ,King LE Jr . Brown recluse spider envenomation of the eyelid: an animal model. Ophthal Plast Reconstr Surg 1995;11:153-164
CrossRef | Web of Science | Medline5
Smith CW ,Micks DW . The role of polymorphonuclear leukocytes in the lesions caused by the venom of the brown spider, Loxosceles reclusa. Lab Invest 1970;22:90-93
Web of Science | Medline6
Patel KD ,Modur V ,Zimmerman GA ,Prescott SM ,McIntyre TM . The necrotic venom of the brown recluse spider induces dysregulated endothelial cell-dependent neutrophil activation. J Clin Invest 1994;94:631-642
CrossRef | Web of Science | Medline
- Citing Articles (2)
Citing Articles
1
Isolete Pauli, Juliana Puka, Ida Cristina Gubert, João Carlos Minozzo. (2006) The efficacy of antivenom in loxoscelism treatment. Toxicon 48:2, 123-137
CrossRef2
Paulo Henrique da Silva, Rafael Bertoni da Silveira, Márcia Helena Appel, Oldemir Carlos Mangili, Waldemiro Gremski, Silvio Sanches Veiga. (2004) Brown spiders and loxoscelism. Toxicon 44:7, 693-709
CrossRef
