Approach to the patient with a suspected spider bite: An overview
- 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
Spider bites are rare medical events. Of the thousands of spider species that exist around the world, only a handful causes problems in humans . There are a variety of more common disorders that can mimic a spider bite, some of which represent a far greater threat to the patient if not recognized and treated appropriately.
Thus, accurate diagnosis is the initial goal of the clinician evaluating a patient with a lesion that might represent a spider bite. Discerning among the various conditions in the differential diagnosis of a spider bite requires familiarity with these disorders, as well as a basic understanding of the distribution and behavior of medically important spiders.
The spiders of medical importance, an overview of the clinical manifestations of their bites, and diagnosis and differential diagnosis of spider bites will be reviewed here. The assessment and management of spider bites caused by recluse and widow spiders are discussed separately. (See "Bites of recluse spiders" and "Clinical manifestations and diagnosis of widow spider bites", section on 'Clinical manifestations' and "Management of widow spider bites".)
MEDICALLY IMPORTANT SPIDERS
Spiders are arachnids (a group of arthropods), which have four pairs of legs, similar to scorpions, mites, and ticks (figure 1). They use sharp fangs at the end of their chelicerae to bite prey (typically insects, other arthropods, or small vertebrates) and inject venom.
Most spiders pose no threat to humans. The venom of most spiders has little or no effect on mammalian tissues [2,3]. In addition, only a few species have cheliceral muscles powerful enough to penetrate human skin, and most of these spiders bite humans only in rare and extreme circumstances (eg, as they are being fatally crushed between skin and some object).
- Vetter RS, Isbister GK. Medical aspects of spider bites. Annu Rev Entomol 2008; 53:409.
- Swanson DL, Vetter RS. Bites of brown recluse spiders and suspected necrotic arachnidism. N Engl J Med 2005; 352:700.
- Liu K, Wang M, Herzig V, et al. Venom from the spider Araneus ventricosus is lethal to insects but inactive in vertebrates. Toxicon 2016; 115:63.
- Isbister GK, Fan HW. Spider bite. Lancet 2011; 378:2039.
- Isbister GK, Graudins A, White J, Warrell D. Antivenom treatment in arachnidism. J Toxicol Clin Toxicol 2003; 41:291.
- Miller M, O'Leary MA, Isbister GK. Towards rationalisation of antivenom use in funnel-web spider envenoming: enzyme immunoassays for venom concentrations. Clin Toxicol (Phila) 2016; 54:245.
- CSL antivenom handbook. CSL funnel web spider antivenom. http://www.toxinology.com/generic_static_files/cslavh_antivenom_funweb.html (Accessed on December 13, 2011).
- Bucaretchi F, Mello SM, Vieira RJ, et al. Systemic envenomation caused by the wandering spider Phoneutria nigriventer, with quantification of circulating venom. Clin Toxicol (Phila) 2008; 46:885.
- Vetter RS, Isbister GK, Bush SP, Boutin LJ. Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis? Am J Trop Med Hyg 2006; 74:1043.
- Isbister GK. Acute allergic reaction following contact with a spider. Toxicon 2002; 40:1495.
- Hasan T, Mäkinen-Kiljunen S, Brummer-Korvenkontio H, et al. Occupational IgE-mediated allergy to a common house spider (Tegenaria domestica). Allergy 2005; 60:1455.
- Castro FF, Antila MA, Croce J. Occupational allergy caused by urticating hair of Brazilian spider. J Allergy Clin Immunol 1995; 95:1282.
- Cooke JA, Miller FH, Grover RW, Duffy JL. Urticaria caused by tarantula hairs. Am J Trop Med Hyg 1973; 22:130.
- Hered RW, Spaulding AG, Sanitato JJ, Wander AH. Ophthalmia nodosa caused by tarantula hairs. Ophthalmology 1988; 95:166.
- Wong RC, Hughes SE, Voorhees JJ. Spider bites. Arch Dermatol 1987; 123:98.
- Stuber M, Nentwig W. How informative are case studies of spider bites in the medical literature? Toxicon 2016; 114:40.
- Russell FE, Gertsch WJ. For those who treat spider or suspected spider bites. Toxicon 1983; 21:337.
- Suchard JR. "Spider bite" lesions are usually diagnosed as skin and soft-tissue infections. J Emerg Med 2011; 41:473.
- Vetter RS, Bush SP. Additional considerations in presumptive brown recluse spider bites and dapsone therapy. Am J Emerg Med 2004; 22:494.
- Vetter RS, Crawford RL, Buckle DJ. Spiders (Araneae) Found in Bananas and Other International Cargo Submitted to North American Arachnologists for Identification. J Med Entomol 2014; 51:1136.
- Spiller HA, Schultz OE. Envenomations as a novel drug-seeking method. Vet Hum Toxicol 2002; 44:297.
- Fisher DP. Letter: Attempted suicide by black widow spider bite. JAMA 1976; 235:2718.
- Dominguez TJ. It's not a spider bite, it's community-acquired methicillin-resistant Staphylococcus aureus. J Am Board Fam Pract 2004; 17:220.
- Al-Asmari AK, Al-Saif AA. Scorpion sting syndrome in a general hospital in Saudi Arabia. Saudi Med J 2004; 25:64.
- Isbister GK, Volschenk ES, Seymour JE. Scorpion stings in Australia: five definite stings and a review. Intern Med J 2004; 34:427.
- MEDICALLY IMPORTANT SPIDERS
- Widow spiders
- False black widow spiders
- Recluse spiders
- Australian funnel web spiders
- South American Phoneutria
- Yellow sac spiders
- TYPES OF REACTIONS
- Local reactions
- Necrotizing local reactions
- Systemic reactions
- Urticating hairs and allergic reactions
- Influence of geographic location
- Laboratory data
- DIFFERENTIAL DIAGNOSIS
- Other bites and stings
- Other common dermatoses
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS