Arthropod Bites and Stings
- Arthropods are the largest division of the animal kingdom. Two classes, insects and arachnids, have the greatest impact on human health.
- Arthropods affect humans by inoculating poison, microorganisms, or irritative substances through a bite or sting; by invading tissue; or by contact allergy to their skin, hairs, or secretions.
- Transmission of infectious microorganisms during feeding is of the greatest concern.
- Sequelae of bites, stings, or contact include
- Local redness with itch, pain, and swelling: common, usually immediate and transient
- Large local reactions that increase over 24 to 48 hours
- Systemic reactions with anaphylaxis, neurotoxicity, organ damage, or other systemic toxin effects
- Tissue necrosis or secondary infection
- Infectious disease transmission: Presentation may be delayed weeks to years.
- 33,671 cases of arthropod exposures were reported in 2016. This is a small fraction of arthropod encounters.
- Systemic reactions to Hymenoptera venom occur in 0.5–3.3% of population and most fatalities involve those with no prior allergic reaction.
Widespread, with regional and seasonal variations
Etiology and Pathophysiology
- Arthropods: four medically important classes
- Insects: Hymenoptera (bees, wasps, hornets, fire ants), mosquitoes, bed bugs, flies, lice, fleas, beetles, caterpillars, and moths
- Arachnids: spiders, scorpions, mites, and ticks
- Chilopods: centipedes
- Diplopods: millipedes
- Four general categories of pathophysiologic effects: toxic, allergic, infectious, and traumatic
- Toxic effects of venom: local (tissue inflammation or destruction) versus systemic (neurotoxic or organ damage)
- Allergic: Antigens in saliva or venom may cause local inflammation. Exaggerated immune responses may result in anaphylaxis or serum sickness.
- Trauma: Mechanical injury from biting or stinging causes pain, swelling, and portal of entry for bacteria and secondary infection. Retention of arthropod parts can cause a granulomatous reaction.
- Infection: Arthropods may transmit bacterial, viral, and protozoal diseases.
Family history of atopy may be a factor in the development of more severe allergic reactions.
- Previous sensitization
- Certain outdoor activities, occupations, and travel exposures increase risk.
- Greater risk for adverse outcome in young, elderly, immunocompromised, and those with chronic or poorly controlled cardiac or respiratory disease
- Increased risk of anaphylaxis in patients with mastocytosis
- Avoid common arthropod habitats.
- Insect repellents (not effective for bees, spiders, scorpions, caterpillars, bed bugs, fleas, ants)
- N,N-diethyl-meta-toluamide (DEET)
- Concentrations >30% have longer duration of action. No significant protection benefits with DEET concentrations >50%.
- Picaridin (icaridin)
- P-menthane-3,8-diol (PMD; lemon eucalyptus extract)
- Not recommended for children <3 years old
- N,N-diethyl-meta-toluamide (DEET)
- Barrier methods: clothing, bed nets
- Wear long pants, long-sleeved shirts, and hats.
- Permethrin: synthetic insecticide derived from chrysanthemum plant. Do not apply directly to skin. Permethrin-impregnated clothing provides good protection against arthropods and is safe for children of all ages and for pregnant women.
- Desensitization 75–95% effective for Hymenoptera-specific venom
- Skin tests to determine sensitivity
- Refer to allergist/immunologist.
- Fire ant control (but not elimination) possible
- Baits; sprays, dusts, aerosols; biologic agents
- Risk of tick-borne diseases may be decreased by prompt removal of ticks within 24 hours of attachment.
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Domino, Frank J., et al., editors. "Arthropod Bites and Stings." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688537/all/Arthropod_Bites_and_Stings.
Arthropod Bites and Stings. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688537/all/Arthropod_Bites_and_Stings. Accessed May 29, 2023.
Arthropod Bites and Stings. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688537/all/Arthropod_Bites_and_Stings
Arthropod Bites and Stings [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 May 29]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688537/all/Arthropod_Bites_and_Stings.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Arthropod Bites and Stings ID - 1688537 ED - Domino,Frank J, ED - Baldor,Robert A, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688537/all/Arthropod_Bites_and_Stings PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -