Anaphylaxis 
 

Acute allergic reaction that have systemic manifestations including:

  1. Skin- flushing, pruritis, hives, angioedema of the eyelids, lips, and glottis.
  2. Gastrointestinal- nausea vomiting, diarrhea, abdominal pain
  3. Cardiovascular- hypotension, arrhythmia, syncope
  4. Respiratory- tearing or itching of eyes, swelling of lips, tongue, and upper airway structures, bronchospasm
Anaphylaxis results from the release of histamine from mast cells and basophils , prostaglandins, leukotrienes and other substances
  1. IgE mediated- there was a previous exposure, usually foods or drugs
  2. Complement system activation- often with blood products like IVIG
  3. Direct mast cell stimulation- contrast materials for xray examinations
  4. Unknown
The reaction may be immediate within seconds, delayed for hours, or be biphasic with recurrence of symptoms or new symptoms. There may be a prodrome such as a rash around the mouth, itchy tongue, lips, or mouth, that may cause the individual to seek attention prior to the development of more serious symptoms. At different times, patients will have a different reaction with the same contact. May be dose related.

Diagnosis
Highly likely when any ONE of the following 3 criteria is fulfilled:

1. Acute onset of an illness with the involvement of the skin, mucosal tissue, or both AND AT LEAST ONE OF THE FOLLOWING
    A. Respiratory compromise
    B. Reduced BP or associated sympotms of end-organ dysfunction

2. TWO OR MORE OF THE FOLLOWING that occur rapidly after exposure to a likely allergen for that patient:
    A. Involvement of the skin-mucosal tissue
    B Respiratory compromise
    C. Reduced BP or associated sympotms
    D. Persistent Gastrointesinal sympotms.

3. Reduced BP after exposure to know allergen for that patient:

  1. Common precipitators of anaphylactic reaction
    1. Foods
      1. Eggs, milk, soy- often outgrow
      2. Nuts, fish, shellfish
      3. Often there are cross reactivity among different foods within groups. It is advisable to avoid all nuts if you are allergic to peanuts unless oral challenges are negative. Avoidance is often difficult. Some foods are labeled under different names and may not be noticed. Also, certain foods have ingredients added that the patient is unaware of. This is especially common in baked goods that contain nuts.
      4. Additives are not common causes of anaphylaxis
    2. Stings- bees, wasps, fire ants. Must differentiate from localized reaction because if it is true anaphylaxis, immunotherapy may be indicated. 
    3. Pharmaceuticals
      1. Penicillin- most skin testing is ineffective because test material doesn't contain material that reaction is against. 
      2. Aspirin, NSAIDs, sulfonamides
      3. Vaccines-All vaccines have been reported to cause anaphylaxis but most discussion is about MMR because it is made with egg products and the high incidence of egg allergies in children. The MMR can be given to individuals sensitive to eggs if you watch them after the shot for 30 minutes and are prepared to give epinephrine. There is no reason to skin test first or give in small doses
      4. Contrast media
      5. Allergy shots- have patient wait after you give the shot to make sure there is no reaction
      6. IVIG
    4. Latex- common in spina bifida and patients with GU anomalies
    5. Exercise- different from exercise induced bronchospasm. May be sporadic and related to something the person ate prior to exercise. Food alone doesn't cause the reaction
    6. Idiopathic- recurrent anaphylaxis without apparent external cause
    Treatment
    1. Be prepared
    2. Assess airway, breathing, and circulation
    3. Place patient in thhe recumbent position with legs elevated
    4. Administer oxygenb by mask
    5. 1/1000 Epinephrine- 0.01ml/kg subcutaneously up to 0.3 ml. May repeat in q 15-20 minutes.
    6. IV normal saline for maintaining perfusion
    7. Diphenyhydramine( Benadryl) Available over the counter in 12.5mg/5cc or 25mg/cap. May be given IM
    8. Steroids- up to 60mg
    9. If severe bronchospasm may give nebulized albuterol
    10. If stridor, may try epinephrine by nebulizer
    11. Careful observation after initiating treatment. Decision on admitting child to hospital is dependent on condition after therapy.
    12. Child should have Medic-Alert bracelet
    13. Family, school, camp, baby-sitter, etc. should be aware of the condition and know what to avoid. Also they should be familiar with reaction and have an Epinephrine 'kit" available and know how to use it.
    14. Patient Counseling
      1. Seek support
      2. Allergen identification and avoidance
      3. Follow up with Allergist
      4. Epinephrine for emergencies
    References
    1. Freeman TM. Anaphylaxis: Diagnosis and Treatment. Primary Care; Clinics in Office Practice. 1998; 25(4):809-817.
    2. Goldstein, H. Drug Sensitivity. Pediatrics in Review. 1998; 19:33. 
    3. Wood RA Anaphylaxis: Causes and Management. Contemporary Pediatrics July 1996 89-105 
    4. Donley DR. Pediatric Anaphylaxis, Insect Stings, and Bites.  Immunology, Allergy Clinics of North America.  May 1999; 19 (2) 347-361
    5. Sampson, Hugh  Peanut Allergy. NEJM Vol 346(17) pp1294-99 April 25, 2002
    6. Leung D. et al. Effect of Anti-IgE Therapy in Patients with Peanut Allergy. NEJM 348:11 pg986 March 13, 2003
    7. Lack G et al. Factors Associated with the Development of Peanut Allergy in Childhood. NEJM Vol 348:11 pg 977 March 13, 2003
    8. Metzger H Two Approaches to Peanut Allergy NEJM Editorial March 13, 2003
    9. Sampson Hugh.Anaphylaxis and Emergency Treatment. Pedatrics Supplement June 2003
    10. Pichichero M. A Review of Evidence Supporting the American Academy of Pediatrics Recommendation for Prescribing Cephalosporin Antibiotics for Pencillin-Allergic Patients. Pediatrics April 2005 pg 1048
    11. Gruchalla R. Pirmohamed M. Antibiotic Allergy NEJM Feb 9, 2006
    12. Lieberman P. Kemp S. etal. The diagnosis and management of anaphylaxis: an updated practice parameter.  J Allergy Clin Immunol 2005 Suppl: S 483
    13. Lack G. Food Allergy.  NEJM Sept 18, 2008
    14. Sampson HA, Munoz-Furlong A.Second Symposium on the definition and management of anaphylaxis: summary report.  Second National Institute of Allergy abd Infectious Diseasae/Food Allergy and Anaphylaxis Newtowrk Symposium.  J. Allergy Clin Immunol 2006 Feb;117(2):391-7.
    15. National Institue of Allergy and Infectious Disease.Guidelines for the Diagnosis and Management of Food Allergy in the United States Dec 2010
    16. Caubet J. et al.The role of penicillin in benign skin rashes in childhood: A prospective study based on drug rechallenge. J of Allergy and Clinical Immunology 2011
    17. Burkes A. et al.  NAID-Sponsored 2010 Guidelines for Mamnaging Food Allergy: Applications for Pediatric Population.  Pediatrics Nov 2011