Bites of recluse spiders
- Richard S Vetter, MS
Richard S Vetter, MS
- Department of Entomology
- University of California, Riverside
- David L Swanson, MD
David L Swanson, MD
- Associate Professor of Dermatology
- Mayo Clinic
- Section Editors
- Daniel F Danzl, MD
Daniel F Danzl, MD
- Section Editor — Environmental Emergencies
- Professor of Emergency Medicine
- University of Louisville School of Medicine
- Stephen J Traub, MD
Stephen J Traub, MD
- Section Editor — Toxicology
- Associate Professor of Emergency Medicine
- Mayo Medical School
- Deputy Editor
- James F Wiley, II, MD, MPH
James F Wiley, II, MD, MPH
- Senior Deputy Editor — Adult and Pediatric Emergency Medicine
- Senior Deputy Editor — Primary Care Sports Medicine (Adolescents and Adults)
- Clinical Professor of Pediatrics and Emergency Medicine/Traumatology
- University of Connecticut School of Medicine
The entomology of recluse spiders (Genus Loxosceles) and the clinical manifestations, diagnosis, differential diagnosis, and management of their bites will be reviewed here.
An overview of spider bites and the management of bites of other spiders are discussed separately. (See "Approach to the patient with a suspected spider bite: An overview".)
ENTOMOLOGY OF RECLUSE SPIDERS
Spiders of the genus Loxosceles are known colloquially as recluse spiders, violin spiders, fiddleback spiders, and in South America, by the nonspecific name "brown spiders." These terms are used when describing multiple Loxosceles species as a group. When the common name "brown recluse spider" is used here, it refers only to the one species, L. reclusa, which is widespread and commonly found in homes in the indigenous Central Midwestern United States.
Loxosceles spiders have gained notoriety in the medical literature and lay press because their bites sometimes become necrotic [1,2]. However, this is a relatively uncommon sequela, and is largely limited to areas of the United States where these spiders are endemic (figure 1). Outside of these regions, the vast majority of necrotic skin lesions are caused by other disorders [3-6]. (See 'Differential diagnosis' below.)
Appearance and identification — Recluse spiders are rather nondescript brown spiders (picture 1 and picture 2). The most accurate method of identifying a recluse spider involves counting the eyes. Most spiders have eight eyes in two rows of four. In contrast, recluse spiders have six eyes, with a pair in front, a pair on both sides, and a gap between the pairs (picture 3). With the naked eye or low magnification, the eye pairs (dyads) may appear as individual eyespots.
- Macchiavello, A. Cutaneous arachidism or gangrenous spot of Chile. Puerto Rico J Pub Health Trop Med 1947; 22:425.
- ATKINS JA, WINGO CW, SODEMAN WA. Probable cause of necrotic spider bite in the Midwest. Science 1957; 126:73.
- Vetter RS, Cushing PE, Crawford RL, Royce LA. Diagnoses of brown recluse spider bites (loxoscelism) greatly outnumber actual verifications of the spider in four western American states. Toxicon 2003; 42:413.
- Vetter RS, Edwards GB, James LF. Reports of envenomation by brown recluse spiders (Araneae: Sicariidae) outnumber verifications of Loxosceles spiders in Florida. J Med Entomol 2004; 41:593.
- Bennett RG, Vetter RS. An approach to spider bites. Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada. Can Fam Physician 2004; 50:1098.
- Frithsen IL, Vetter RS, Stocks IC. Reports of envenomation by brown recluse spiders exceed verified specimens of Loxosceles spiders in South Carolina. J Am Board Fam Med 2007; 20:483.
- Vetter R. Identifying and misidentifying the brown recluse spider. Dermatol Online J 1999; 5:7.
- Vetter RS. Arachnids submitted as suspected brown recluse spiders (Araneae: Sicariidae): Loxosceles spiders are virtually restricted to their known distributions but are perceived to exist throughout the United States. J Med Entomol 2005; 42:512.
- Swanson DL, Vetter RS. Loxoscelism. Clin Dermatol 2006; 24:213.
- Swanson DL, Vetter RS. Bites of brown recluse spiders and suspected necrotic arachnidism. N Engl J Med 2005; 352:700.
- Vetter RS, Barger DK. An infestation of 2,055 brown recluse spiders (Araneae: Sicariidae) and no envenomations in a Kansas home: implications for bite diagnoses in nonendemic areas. J Med Entomol 2002; 39:948.
- Sandidge J. Predation by cosmopolitan spiders upon the medically significant pest species Loxosceles reclusa (Araneae: Sicariidae): limited possibilities for biological control. J Econ Entomol 2004; 97:230.
- Anderson PC. Spider bites in the United States. Dermatol Clin 1997; 15:307.
- Sams HH, Hearth SB, Long LL, et al. Nineteen documented cases of Loxosceles reclusa envenomation. J Am Acad Dermatol 2001; 44:603.
- Málaque CM, Castro-Valencia JE, Cardoso JL, et al. Clinical and epidemiological features of definitive and presumed loxoscelism in São Paulo, Brazil. Rev Inst Med Trop Sao Paulo 2002; 44:139.
- Binford GJ, Wells MA. The phylogenetic distribution of sphingomyelinase D activity in venoms of Haplogyne spiders. Comp Biochem Physiol B Biochem Mol Biol 2003; 135:25.
- Tambourgi DV, Paixão-Cavalcante D, Gonçalves de Andrade RM, et al. Loxosceles sphingomyelinase induces complement-dependent dermonecrosis, neutrophil infiltration, and endogenous gelatinase expression. J Invest Dermatol 2005; 124:725.
- Isbister GK, Fan HW. Spider bite. Lancet 2011; 378:2039.
- Anderson PC. Loxoscelism threatening pregnancy: five cases. Am J Obstet Gynecol 1991; 165:1454.
- Tutrone WD, Green KM, Norris T, et al. Brown recluse spider envenomation: dermatologic application of hyperbaric oxygen therapy. J Drugs Dermatol 2005; 4:424.
- Wilson DC, King LE Jr. Spiders and spider bites. Dermatol Clin 1990; 8:277.
- Stoecker WV, Wasserman GS, Calcara DA, et al. Systemic loxoscelism confirmation by bite-site skin surface: ELISA. Mo Med 2009; 106:425.
- Futrell JM. Loxoscelism. Am J Med Sci 1992; 304:261.
- Kemp ED. Bites and stings of the arthropod kind. Treating reactions that can range from annoying to menacing. Postgrad Med 1998; 103:88.
- França FO, Barbaro KC, Abdulkader RC. Rhabdomyolysis in presumed viscero-cutaneous loxoscelism: report of two cases. Trans R Soc Trop Med Hyg 2002; 96:287.
- Rosen JL, Dumitru JK, Langley EW, Meade Olivier CA. Emergency department death from systemic loxoscelism. Ann Emerg Med 2012; 60:439.
- Said A, Hmiel P, Goldsmith M, et al. Successful use of plasma exchange for profound hemolysis in a child with loxoscelism. Pediatrics 2014; 134:e1464.
- Dare RK, Conner KB, Tan PC, Hopkins RH Jr. Brown recluse spider bite to the upper lip. J Ark Med Soc 2012; 108:208.
- Hubbard JJ, James LP. Complications and outcomes of brown recluse spider bites in children. Clin Pediatr (Phila) 2011; 50:252.
- McDade J, Aygun B, Ware RE. Brown recluse spider (Loxosceles reclusa) envenomation leading to acute hemolytic anemia in six adolescents. J Pediatr 2010; 156:155.
- Wasserman GS, Garola R, Marshall J, Gustafson S. Death of a 7 year old by presumptive brown recluse spider bite. J Toxicol Clin Toxicol 1999; 37:614.
- Stoecker WV, Green JA, Gomez HF. Diagnosis of loxoscelism in a child confirmed with an enzyme-linked immunosorbent assay and noninvasive tissue sampling. J Am Acad Dermatol 2006; 55:888.
- Dominguez TJ. It's not a spider bite, it's community-acquired methicillin-resistant Staphylococcus aureus. J Am Board Fam Pract 2004; 17:220.
- El Fakih, RO, Moore, TA, Mortada, RA. The danger of diagnostic error: community-acquired MRSA or a spider bite? Kansas J Med 2008; 1:81.
- DiCaudo DJ, Connolly SM. Neutrophilic dermatosis (pustular vasculitis) of the dorsal hands: a report of 7 cases and review of the literature. Arch Dermatol 2002; 138:361.
- Manríquez JJ, Silva S. [Cutaneous and visceral loxoscelism: a systematic review]. Rev Chilena Infectol 2009; 26:420.
- Bryant SM, Pittman LM. Dapsone use in Loxosceles reclusa envenomation: is there an indication? Am J Emerg Med 2003; 21:89.
- Hahn I. Arthropods. In: Goldfrank's Toxicologic Emergencies, 10th edition, Hoffman RS, Howland MA, Lewin NA, et al. (Eds), McGraw Hill Education, China 2015. p.1462.
- Wong SL, Defranzo AJ, Morykwas MJ, Argenta LC. Loxoscelism and negative pressure wound therapy (vacuum-assisted closure): a clinical case series. Am Surg 2009; 75:1128.
- Wong SL, Schneider AM, Argenta LC, Morykwas MJ. Loxoscelism and negative pressure wound therapy (vacuum-assisted closure): an experimental study. Int Wound J 2010; 7:488.
- Paixão-Cavalcante D, van den Berg CW, Gonçalves-de-Andrade RM, et al. Tetracycline protects against dermonecrosis induced by Loxosceles spider venom. J Invest Dermatol 2007; 127:1410.
- Berger RS. The unremarkable brown recluse spider bite. JAMA 1973; 225:1109.
- Paixão-Cavalcante D, van den Berg CW, de Freitas Fernandes-Pedrosa M, et al. Role of matrix metalloproteinases in HaCaT keratinocytes apoptosis induced by loxosceles venom sphingomyelinase D. J Invest Dermatol 2006; 126:61.
- Auer AI, Hershey FB. Proceedings: Surgery for necrotic bites of the brown spider. Arch Surg 1974; 108:612.
- DeLozier JB, Reaves L, King LE Jr, Rees RS. Brown recluse spider bites of the upper extremity. South Med J 1988; 81:181.
- 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.
- Pauli I, Puka J, Gubert IC, Minozzo JC. The efficacy of antivenom in loxoscelism treatment. Toxicon 2006; 48:123.
- Pauli I, Minozzo JC, da Silva PH, et al. Analysis of therapeutic benefits of antivenin at different time intervals after experimental envenomation in rabbits by venom of the brown spider (Loxosceles intermedia). Toxicon 2009; 53:660.
- Hogan CJ, Barbaro KC, Winkel K. Loxoscelism: old obstacles, new directions. Ann Emerg Med 2004; 44:608.
- Isbister GK, Graudins A, White J, Warrell D. Antivenom treatment in arachnidism. J Toxicol Clin Toxicol 2003; 41:291.
- Bernstein JN. Antidotes in depth. In: Goldfrank's Toxicologic Emergencies, 8th ed, Flomenbaum NE, Goldfrank LR, et al (Eds), McGraw Hill, New York 2006. p.1623.
- ENTOMOLOGY OF RECLUSE SPIDERS
- Appearance and identification
- Geographic location
- - Habitat
- CLINICAL MANIFESTATIONS OF BITES
- Venom properties
- Clinical history
- Findings following bites
- - Local effects
- - Systemic findings
- Life-threatening effects
- Further evaluation
- DIFFERENTIAL DIAGNOSIS
- Solitary ulcerated lesion
- - Infections
- - Vascular disease
- - Pyoderma gangrenosum
- - Vasculitis
- - Pustular dermatosis of the dorsal hand
- Systemic reactions
- Patients with local effects
- - Wound care and general measures
- - Dermal necrosis
- Patients with systemic toxicity
- - Acute hemolytic anemia
- - Rhabdomyolysis
- - Disseminated intravascular coagulopathy
- South American recluse spider bites
- PEDIATRIC CONSIDERATIONS
- DISCHARGE INSTRUCTIONS AND AFTER CARE
- ADDITIONAL RESOURCES
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS