Thursday, June 20, 2013

Exercise Induced Anaphylaxis!

Anaphylaxis is a life-threatening, multi-system disorder caused by the sudden release of basophil and mast cell inflammatory mediators. Anaphylaxis can range from mild signs to overt shock. Rapid identification and treatment must be started to prevent progression to full respiratory or circulatory collapse.

A consensus criteria was created in 2006, outlining three criteria for anaphylaxis, of which only one is needed to make the diagnosis highly likely:

  • Acute onset of illness involving skin/mucosa (hives, pruritis, angioedema) and either respiratory or hemodynamic compromise (SBP less than 90mmHg)
  • At least 2 signs and sx occurring following exposure to a likely allergen or trigger
  • Systolic BP less than 90 or symptomatic hypotension following a likely allergen or trigger
Allergic Anaphylaxis:

  • Immunologically mediated involving IgE and IgG or immune complex-complement interactions. 
  • Common triggers: food, insect stings, medications
  • Food allergies are more common in children, while insect stings and medication allergy is more common in adults.
Non-allergic anaphylaxis:

  • Previously referred to as "Anaphylactoid" reactions. These are non-immunologic and non-IgE-mediated reaction.
  • Common triggers: anesthetics, latex, seminal fluid, exercise
Exercise induced Anaphylaxis:

  • Typically presents during or shortly after exercising
  • Signs and symptoms include: fatigue, warmth, pruritis, flushing and urticaria. In extreme cases, it may progress to angioedema, bronchospasm, airway compromise and full circulatory collapse.
  • Many patients do not consistently have symptoms with regular exercise and may experience symptoms monthly or years apart.
  • Patients are instructed to carry an epinepherine autoinjector when exercising, exercise with a partner trained in symptoms recognition and epinepherine injection and to avoid all food, alcohol, NSAIDs at least 4 hours prior to exercise.
Food-Dependent Exercise Induced Anaphylaxis:
  • Known triggers include: NSAIDs, alcohol, and cereals containing wheat gliadin (barley, rye, oats and wheat)
  • Patients may be unaware of a food allergy, as symptoms only occur in association with post-prandial exercise. Patients can be tested with skin prick testing using NaCl wheat suspensions.
  • Patients with allergy to wheat gliadin directed to eat a gluten free diet may continue physical activities with no symptoms

For more information refer to the following interesting articles:
Exercise induced Anaphylaxis and association with allergy to Gliadin
Case report of exercise induced anaphylaxis
Review on Exercise induced Anaphylaxis