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The more rapidly anaphylaxis develops, the more likely the reaction is to be severe and potentially life-threatening. Most deaths due to anaphylaxis occur within 30 to 60 minutes of sting.
Epinephrine should be given as soon as diagnosis of anaphylaxis is suspected. Delay of epinephrine is associated with fatal anaphylaxis (4,5).
Antihistamines and steroids do not replace epinephrine in anaphylaxis, and no direct outcome data regarding their effectiveness in anaphylaxis are available (4,5).
Airway management critical if angioedema
GENERAL MEASURES
Local wound care, ice compress, elevation, analgesics
MEDICATION
First Line
- For arthropod bites/stings with anaphylaxis
- There are no randomized controlled trials on treatments, so the following recommendations are all based on expert opinion consensus (5)[C].
- Epinephrine: most important: IM injection in midanterolateral thigh (vastus lateralis muscle):
- IM injection: epinephrine 1:1,000 (1 mg/mL): adult: 0.3 to 0.5 mg per dose; pediatric: give 0.01 mg/kg to a maximum dose of 0.5 mg per dose, can repeat every 5 to 15 minutes (5)
- Positioning: supine with legs elevated
- Oxygen 6 to 8 L/min up to 100%, as needed
- IV fluids: Establish 1 to 2 large-bore IV lines. Normal saline rapid bolus 1 to 2 L IV; repeat as needed (pediatrics 20 to 30 mL/kg)
- H1 antihistamines: diphenhydramine 25 to 50 mg IV (pediatrics 1 to 2 mg/kg)
- β2 agonists: albuterol for bronchospasm nebulized 2.5 to 5 mg in 3 mL
- Emergency treatment of refractory cases: consider epinephrine infusion, dopamine, glucagon, vasopressin, large-volume crystalloids (4,5)
- Arthropod bites/stings without anaphylaxis
- Tetanus booster, as indicated
- Oral antihistamines
- Diphenhydramine
- Cetirizine
- H2 blockers: ranitidine
- Oral steroids: consider short course for severe pruritus; prednisone or prednisolone 1 to 2 mg/kg once daily
- Topical intermediate-potency steroid cream or ointment 3 to 5 days
- Desoximetasone 0.05%
- Triamcinolone 0.1%
- Fluocinolone 0.025%
- Wound care: antibiotics only if infection
- Other specific therapies:
- Scorpion stings: Treat excess catecholamine release (nitroprusside, prazosin, β-blockers). Diazepam for muscle spasms. Atropine for hypersalivation (6). Only one FDA-approved scorpion antivenom in United States and should be administered in conjunction with toxicologist. Black widow bites: Treat muscle spasms with diazepam and opioid analgesics PO or IV (6). Antivenom: available but should be administered in conjunction with toxicologist.
- Poison control should be consulted for questions regarding management of envenomation. Poison Control hotline: 1-800-222-1222.
- Fire ants: characteristically cause sterile pustules. Leave intact: Do not open or drain.
- Brown recluse spider: pain control, supportive treatment; surgical consult if d ©bridement needed
- Ticks: early removal. Review guidelines for disease prophylaxis and treatment.
- Pediculosis: head, pubic, and body lice
- First line: permethrin 1% (Nix) topical lotion. Apply to affected area, wash off in 10 minutes.
- Alternatives: pyrethrin or malathion 0.5% lotion, ivermectin (not FDA approved for pediculosis) orally
- Repeat above treatment in 7 to 10 days.
- For eyelash infestation: Apply ophthalmic-grade petroleum jelly BID for 10 days.
- Sarcoptes scabiei scabies
- Permethrin 5% cream: Apply to entire body. Wash off after 8 to 14 hours. Repeat in 1 week.
- Ivermectin: 200 μg/kg PO once; repeat in 2 weeks (not FDA approved for this use)
- Crotamiton 10% cream or lotion less efficacious; apply daily for 2 days after bathing.
Second Line
Second-line options for anaphylaxis:
- Ranitidine
- Methylprednisolone 1 mg/kg for 3 to 4 days or hydrocortisone 200 mg (5)
ISSUES FOR REFERRAL
Refer to allergist with history of anaphylaxis, severe systemic symptoms, or progressively severe reactions
SURGERY/OTHER PROCEDURES
D ©bridement and delayed skin grafting may be needed for brown recluse spider and other bites.
COMPLEMENTARY & ALTERNATIVE MEDICINE
- Some stings may be treated with a paste of 3 tsp of baking soda and 1 tsp water.
- None well tested
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Anaphylaxis, vascular instability, neuromuscular events, pain, GI symptoms, renal damage/failure
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Immunotherapy as recommended by allergist/consultant for anaphylaxis or serious reactions; venom immunotherapy cornerstone of treatment for Hymenoptera.
- Patient-administered epinephrine must be provided to patients with anaphylaxis. Consider "med-alert" identifiers (4,5).
Patient Monitoring
- Monitor for delayed effects, including infectious diseases from arthropod vectors.
- Serum sickness reactions, vasculitis (rare)
PATIENT EDUCATION
Avoidance and prevention
PROGNOSIS
- Excellent for local reactions
- For systemic reactions, best response with early intervention to prevent cardiorespiratory collapse
COMPLICATIONS
- Scarring
- Secondary bacterial infection
- Arthropod-associated diseases as mentioned earlier
- Psychological effects, phobias
REFERENCES
11 Tanskersley MS, Ledford DK. Stinging insect allergy: state of the art 2015. J Allergy Clin Immunol Pract. 2015;3(3):315-322.22 Diaz JH. Recognition, management, and prevention of hymenopteran stings and allergic reactions in travelers. J Travel Med. 2009;16(5):357-364.33 Moore SJ, Mordue Luntz AJ, Logan JG. Insect bite prevention. Infect Dis Clin North Am. 2012;26(3):655-673.44 Simons FE, Ardusso LR, Bil ² MB, et al. 2012 update: World Allergy Organization guidelines for the assessment and management of anaphylaxis. Curr Opin Allergy Clin Immunol. 2012;12(4):389-399.55 De Bisschop MB, Bellou A. Anaphylaxis. Curr Opin Crit Care. 2012;18(4):308-317.66 Quan D. North American poisonous bites and stings. Crit Care Clin. 2012;28(4):633-659.
ADDITIONAL READING
- Centers for Disease Control and Prevention. Protection against mosquitoes, ticks, & other insects & arthropods. http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-2-the-pre-travel-consultation/protection-against-mosquitoes-ticks-and-other-insects-and-arthropods. Accessed 2015.
- Centers for Disease and Prevention. FAQ. Insect repellent use & safety. http://www.cdc.gov/westnile/faq/repellent.html. Accessed 2015.
- Centers for Disease Control and Prevention. Tickborne diseases of the United States: a reference manual for health care providers. Third edition, 2015. Handbook available as a PDF at http://www.cdc.gov/ticks/
- Sicherer SH, Leung DY. Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2012. J Allergy Clin Immunol. 2013;131(1):55-66.
- Studdiford JS, Conniff KM, Trayes KP, et al. Bedbug infestation. Am Fam Physician. 2012;86(7):653-658.
- Swanson DL, Vetter RS. Bites of brown recluse spiders and suspected necrotic arachnidism. N Engl J Med. 2005;352(7):700-707.
- Warrell DA. Venomous bites, stings, and poisoning. Infect Dis Clin North Am. 2012;26(2):207-223.
- Juckett G. Arthropod bites. Am Fam Physician. 2013; 88(12):841-847.
CODES
ICD10
- T63.481A Toxic effect of venom of arthropod, accidental, init
- T63.301A Toxic effect of unsp spider venom, accidental, init
- T63.484A Toxic effect of venom of oth arthropod, undetermined, init
- T63.304A Toxic effect of unsp spider venom, undetermined, init encntr
ICD9
- 919.4 Insect bite, nonvenomous, of other, multiple, and unspecified sites, without mention of infection
- 989.5 Toxic effect of venom
SNOMED
- 299971005 insect sting (disorder)
- 276433004 Insect bite - wound (disorder)
- 55308005 Poisoning due to insect venom
- 429305003 Nonvenomous insect bite
- 15056007 poisoning due to arthropod venom (disorder)
CLINICAL PEARLS
- Urgent administration of epinephrine is a key to anaphylaxis treatment.
- Local treatment and symptom management are sufficient in most insect bites and stings.