Doctor123.org

Anaphylaxis

Doctor123.org

Anaphylaxis

para>Have a latex-free kit (gloves, etc.) available for the treatment of latex-allergic patients. Some latex-allergic patients will react to tropical fruits, such as kiwi, bananas, avocados, and chestnuts.

Rapid progression within minutes to hours of the signs and symptoms of anaphylaxis, with or without an obvious trigger, including but not limited to cutaneous symptoms (>90% of cases), respiratory symptoms (40-60%), GI symptoms (25-30%), and cardiovascular symptoms (30-35%)

Initial Tests (lab, imaging)

Admission Criteria/Initial Stabilization

Moderate to severe anaphylaxis, admit for observation for 8 to 24 hours.

Outpatient: Patients with cutaneous angioedema, urticaria, without bronchospasm may be released when symptoms and signs have cleared.

Bed rest until anaphylaxis clears and patient is hemodynamically stable

NPO until acute symptoms are controlled

11 Brown SG, Blackman KE, Heddle RJ. Can serum mast cell tryptase help diagnose anaphylaxis? Emerg Med Australas. 2004;16(2):120-124.22 Narita M, Nomura I, Aota A, et al. Usefulness of serum tryptase in the diagnosis of anaphylaxis by food allergy in childhood. J Allergy Clin Immunol. 2006;7(2):s307.33 Choo KJ, Simons E, Sheikh A. Glucocorticoids for the treatment of anaphylaxis: Cochrane systematic review. Allergy. 2010;65(10):1205-1211.44 Brown SG, Wiese MD, Blackman KE, et al. Ant venom immunotherapy: a double-blind, placebo-controlled, crossover trial. Lancet. 2003;361(9362):1001-1006.

Arthropod Bites and Stings; Food Allergy

Avoid β-blockers.

COMMONLY ASSOCIATED CONDITIONS

  • Asthma
  • Atopy

DIAGNOSIS

HISTORY

PHYSICAL EXAM

  • Pruritus, flushing, urticaria, angioedema
  • Dyspnea, cough, rhonchi
  • Rhinorrhea, bronchorrhea, wheezing, stridor
  • Difficulty swallowing
  • Nausea, vomiting, diarrhea, cramps, bloating
  • Tachycardia, hypotension, shock, syncope
  • Malaise, shivering
  • Mydriasis

DIFFERENTIAL DIAGNOSIS

  • Vasodepressor reactions: most commonly mimics anaphylaxis (i.e., Bezhold-Jarisch reflex, vasodilatation, bradycardia, hypotension, resulting in pallor, nausea, vomiting, and weakness)
  • Flushing syndromes: carcinoid, alcohol ingestion, spicy foods, drug-ingestion (i.e., disulfiram, griseofulvin, and cephalosporins), medullar carcinoma of thyroid, and pheochromocytomaWet versus dry flushingWet: sweating mediated by sympathetic cholinergic nervesDry: direct vasodilation (i.e., carcinoid also releases histamine, kallikrein, and prostaglandins)
  • Restaurant syndromesMSG ingestion (Chinese restaurant syndrome)SulfitesScombroisosis: histamine poisoning secondary to ingestion of histamine in spoiled fish (i.e., tuna, mackerel)
  • Excess endogenous production of histamine syndromesSystemic mastocytosisUrticaria pigmentosaBasophilic leukemia
  • Nonorganic diseasePanic attackVocal cord dysfunction syndromeGlobus hystericusMunchausen stridor
  • Hereditary angioedema: rare autosomal dominant condition caused by low levels of plasma C1 inhibitor (inhibits the kinin pathway)
  • Tracheal foreign body
  • Pseudoanaphylaxis: syncope and neurologic symptoms after administration of procaine penicillin. Reaction is caused by procaine, not penicillin.
  • Red man syndrome (i.e., vancomycin)
  • Wet versus dry flushingWet: sweating mediated by sympathetic cholinergic nervesDry: direct vasodilation (i.e., carcinoid also releases histamine, kallikrein, and prostaglandins)
  • Wet: sweating mediated by sympathetic cholinergic nerves
  • Dry: direct vasodilation (i.e., carcinoid also releases histamine, kallikrein, and prostaglandins)
  • MSG ingestion (Chinese restaurant syndrome)
  • Sulfites
  • Scombroisosis: histamine poisoning secondary to ingestion of histamine in spoiled fish (i.e., tuna, mackerel)
  • Systemic mastocytosis
  • Urticaria pigmentosa
  • Basophilic leukemia
  • Panic attack
  • Vocal cord dysfunction syndrome
  • Globus hystericus
  • Munchausen stridor

DIAGNOSTIC TESTS & INTERPRETATION

  • Little data to support extensive testing; targeted IgE antibodies of little value due to low sensitivity and specificity
  • Elevated serum tryptase, a mast cell enzyme for allergic and anaphylactic reactions (1)[B], plasma histamine, and 24-hour urinary histamine metabolites (i.e., N-methylhistamine)
  • Tryptase: sensitivity of 89% and specificity of 88% (2)[B]
  • Plasma histamine levels begin to rise within 5 to 10 minutes and remain elevated for 30 to 60 minutes and are little help if patient is seen after 1 hour of event onset.
  • Tryptase peaks 60 to 90 minutes after onset of anaphylaxis and persist longer than histamine, up to 5 hours after onset (must be drawn within 90 minutes).
  • Other markers include CD63, CD203c, prostaglandin D2, and carboxypeptidase.

TREATMENT

GENERAL MEASURES

  • Treatment depends on severity.
  • Maintain a patent airway.Endotracheal intubation and assisted ventilation may be necessary.Possibly tracheostomy or needle cricothyrotomy in children <12 years
  • Oxygen
  • Supine position, legs elevated (if in shock)
  • IV fluids (normal saline/lactated Ringer)
  • Endotracheal intubation and assisted ventilation may be necessary.
  • Possibly tracheostomy or needle cricothyrotomy in children <12 years

MEDICATION

  • EpinephrineLess severe reaction: 0.3 to 0.5 mg (0.01 mg/kg in children) = (0.3 to 0.5 mL of a 1:1,000 solution, 0.01 mL/kg in children), IM lateral thigh q20-30min PRN, up to 3 dosesLife-threatening reactions: 0.5 mg (5 mL of a 1:10,000 solution) (for children: 0.05 to 0.1 mL/kg per dose) IV, slowly: q5-10min as needed. If IV access is not possible, endotracheal or intraosseous may be effective.
  • Antihistamines: not life-saving, but alleviate itching and urticarial. Vasodilatory effect and can trigger hypotension, thus, must be given with epinephrineDiphenhydramine: an H1 blocker: 25 to 50 mg IV (IM or PO) q6h for 72 hours (children 1.25 mg/kg to 25 mg)Cimetidine: an H2 blocker: 300 mg IV over 3 to 5 minutes (children 5 to 10 mg/kg per dose) and then 400 mg PO BID is helpful and may be more effective than diphenhydramine.
  • Corticosteroids: although routinely used, no immediate effect and no evidence for their use in the emergency department (3)[B]Hydrocortisone sodium succinate: 250 to 500 mg IV q4-6h (4 to 8 mg/kg for children)
  • Prednisone: 1 mg/kg in children, up to 60 mg
  • Methylprednisolone: 60 to 125 mg IV in adults (1 to 2 mg/kg in children)
  • Bronchodilator, if persistent bronchospasmInhaled β2 agonists. Continuous nebulized albuterol of 10 mg/hr or 2.5 mg q15-20min is safe, effective, and preferable to aminophylline as a first line.
  • Laryngeal edemaEpinephrine: 5 mL of 1:1,000 by nebulizer is more effective than racemic epinephrine and is usually available.
  • Persistent hypotensionDopamine: 400 mg in 500 mL of dextrose in water given by infusion pump; titrate to BP (2 to 20 μg/kg/min).Atropine: adult (0.3 to 0.5 mg IV q10min PRN, max dose 2 mg) in case of bradycardiaGlucagon: may be beneficial for resistant hypotension caused by concurrent β-blockade therapy; 50 μg/kg IV bolus over 1 minute, or alternatively, give as continuous infusion at 5 to 15 μg/min
  • Normal saline or Ringer lactate: adult (1 to 2 L rapidly), child (30 mL/kg in the 1st hour)
  • Oral antihistamines for 72 hours
  • Less severe reaction: 0.3 to 0.5 mg (0.01 mg/kg in children) = (0.3 to 0.5 mL of a 1:1,000 solution, 0.01 mL/kg in children), IM lateral thigh q20-30min PRN, up to 3 doses
  • Life-threatening reactions: 0.5 mg (5 mL of a 1:10,000 solution) (for children: 0.05 to 0.1 mL/kg per dose) IV, slowly: q5-10min as needed. If IV access is not possible, endotracheal or intraosseous may be effective.
  • Diphenhydramine: an H1 blocker: 25 to 50 mg IV (IM or PO) q6h for 72 hours (children 1.25 mg/kg to 25 mg)
  • Cimetidine: an H2 blocker: 300 mg IV over 3 to 5 minutes (children 5 to 10 mg/kg per dose) and then 400 mg PO BID is helpful and may be more effective than diphenhydramine.
  • Hydrocortisone sodium succinate: 250 to 500 mg IV q4-6h (4 to 8 mg/kg for children)
  • Inhaled β2 agonists. Continuous nebulized albuterol of 10 mg/hr or 2.5 mg q15-20min is safe, effective, and preferable to aminophylline as a first line.
  • Epinephrine: 5 mL of 1:1,000 by nebulizer is more effective than racemic epinephrine and is usually available.
  • Dopamine: 400 mg in 500 mL of dextrose in water given by infusion pump; titrate to BP (2 to 20 μg/kg/min).
  • Atropine: adult (0.3 to 0.5 mg IV q10min PRN, max dose 2 mg) in case of bradycardia
  • Glucagon: may be beneficial for resistant hypotension caused by concurrent β-blockade therapy; 50 μg/kg IV bolus over 1 minute, or alternatively, give as continuous infusion at 5 to 15 μg/min

Epinephrine may induce myocardial ischemia in those with cardiac disease, but it is the drug of choice. Be alert for anticholinergic and CNS side effects after giving diphenhydramine or cimetidine.

Epinephrine could reduce the placental blood flow but may save the life of the mother and fetus. It also increases the risk of congenital malformation.

  • Several reports of tranexamic acid: 1,000 mg IV or sigma-aminocaproic acid for refractory anaphylaxis
  • These drugs are not standard care; used only in patients who do not respond to other therapy
  • Aminophylline: 5 to 6 mg/kg IV in 100 mL D5W over 20 minutes, then maintenance at 1 mg/kg/hr drip
  • Anti-IgE monoclonal antibody may have a role in long-term management of food-induced anaphylaxis.
  • Venom immunotherapy has been effective in the prevention of sting anaphylaxis but with a high side-effect risk (4)[A].

ISSUES FOR REFERRAL

  • Allergist referral if anaphylaxis cause unclear
  • Patients with anaphylaxis from insect stings benefit from desensitization immunotherapy.

INPATIENT CONSIDERATIONS

DISCHARGE CRITERIA

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

DIET

PATIENT EDUCATION

  • Asthma and Allergy Foundation of America, 1717 Massachusetts Avenue, Suite 305, Washington, DC 20036; (800)-7-ASTHMA or American Allergy Association, P.O. Box 7273, Menlo Park, CA 94026, (415) 322-1663
  • Medic-Alert-type tags (Medic-Alert Foundation, Turlock, CA 95381-1009)
  • Avoid β-blockers, if possible.
  • Instruct patient in the use of the epinephrine auto-injector (Epipen) usage.

PROGNOSIS

  • Good prognosis if treated immediately; worse outcome with a delay of >30 minutes in administration of epinephrine
  • Of those with idiopathic anaphylaxis, 60% are free of anaphylactic episodes at 2.5 years.

COMPLICATIONS

  • Hypoxemia
  • Cardiac arrest
  • Death

REFERENCES

ADDITIONAL READING

  • Gonz ¡lez-P ©rez A, Aponte Z, Vidaurre CF, et al. Anaphylaxis epidemiology in patients with and patients without asthma: a United Kingdom database review. J Allergy Clin Immunol. 2010;125(5):1098.e1-1104.e1.
  • Lieberman P, Kemp S, Oppenheimer J, et al. The diagnosis and management of anaphylaxis: an updated practice parameter. J Allergy Clin Immunol. 2005;115(3)(Suppl 2):S483-S523.
  • Pitsios C, Dimitriou A, Stefanaki EC, et al. Anaphylaxis during skin testing with food allergens in children. Eur J Pediatr. 2010;169(5):613-615.
  • Sheikh A, Shehata YA, Brown SG, et al. Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock. Cochrane Database Syst Rev. 2008;(4):CD006312.
  • Sheikh A, ten Broek V, Brown SG, et al. H1-antihistamines for the treatment of anaphylaxis with and without shock. Cochrane Database Syst Rev. 2007;(1):CD006160.
  • Tanus T, Mines D, Atkins PC, et al. Serum tryptase in idiopathic anaphylaxis: a case report and review of the literature. Ann Emerg Med. 1994;24(1):104-107.
  • Wittbrodt ET, Spinler SA. Prevention of anaphylactoid reactions in high-risk patients receiving radiographic contrast media. Ann Pharmacother. 1994;28(2):236-241.

SEE ALSO

CODES

ICD10

  • T78.00XA Anaphylactic reaction due to unspecified food, init encntr
  • T88.6XXA Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter
  • T78.2XXA Anaphylactic shock, unspecified, initial encounter
  • T63.91XA Toxic effect of contact w unsp venomous animal, acc, init
  • T78.00XD Anaphylactic reaction due to unspecified food, subs encntr
  • T88.6XXD Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, sunsequent encounter
  • T88.6XXS Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, sequela
  • T63.91XD Toxic effect of contact w unsp venomous animal, acc, subs
  • T63.91XS Toxic effect of contact w unsp venom animal, acc, sequela
  • T78.2XXD Anaphylactic shock, unspecified, subsequent encounter
  • T78.2XXS Anaphylactic shock, unspecified, sequela
  • T78.00XS Anaphylactic reaction due to unspecified food, sequela

ICD9

  • 995.0 Other anaphylactic reaction
  • 995.60 Anaphylactic reaction due to unspecified food
  • 989.5 Toxic effect of venom

SNOMED

  • Anaphylaxis (disorder)
  • Drug-induced anaphylaxis (disorder)
  • Food anaphylaxis (disorder)
  • Anaphylaxis secondary to bite and/or sting (disorder)

CLINICAL PEARLS

  • Allergy to one species of legume (e.g., peanuts) or one type of seafood (e.g., shrimp) does not mean allergy to all products in that category. Skin testing is useful.
  • Measles, mumps, rubella (MMR) and influenza vaccines can be safely administered to those with a history of egg allergy.
  • Penicillin-allergic patients can generally tolerate 2nd- and 3rd-generation cephalosporins as well as monobactams (e.g., aztreonam). Generally, they will be allergic to carbapenems (e.g., imipenem) and 1st-generation cephalosporins.
  • IgA-deficient patients should have washed RBCs for transfusion.
  • Those allergic to seafood are not allergic to iodine-based radiocontrast. Shellfish allergy is protein-related.