Anaphylaxis is a severe, whole-body allergic reaction to an allergen. Anaphylaxis happens quickly after allergen exposure, is severe, and involves the whole body. Anaphylaxis affects between 1.5% and 5% of people.
Dr. Phil Lieberman discusses the diagnosis and management of anaphylaxis. Presented on July 22, 2016:
There is a difference between anaphylactic (IgE-mediated) and anaphylactoid reaction (non-IgE mediated).
Females predominate in terms of prevalence of anaphylaxis.
Cytokines and mediators released during anaphylaxis include: IL-2, IL-6, IL-10, TNF receptor I, MCT, histamine.
Alpha-gal anaphylaxis is an example of delayed anaphylaxis. Galactose-alpha-1,3-Galactose is an antigen. Lone star tick contains Galactose-alpha-1,3-Galactose. If you are bitten by the tick, you can get sensitized to Galactose-alpha-1,3-Galactose. You can get an ahaphylaxis afer eating meat because
- Sx are delayed, 3-6 hours - in the middle of the night after eating a meal.
- it may not occur after each ingestion
- negative prick test wtih meat extracts. Intradermal test with fresh meat are often positive.
Alpha gal assessment on any patient with idiopathic anaphylaxis.
Mast cell activation syndrome (MCAS). Abberant mast cell population can be present in idiopathic anaphylaxis.
MCAS criteria: 20% increase + 2 ng/mL in tryptase within 4 hr of reaction.
Causes of anaphylaxis in adults
- Idiopathic in 61% of cases
- Food in 22%
- Medications in 11%
- Exercise in 5%
Dr Lieberman checks alpha gal and tryptase in all patients with idiopathic anaphylaxis. Consider abberant mast cell population if elevated baseline tryptase.
In children, almost all of anaphylaxis is related to food allergy.
Recognizing mastocytosis in patients with anaphylaxis: peripheral blood for KIT D816V mutation (costs $60). Bone marrow biopsy may be indicated even with normal tryptase.
Surprisingly, normally, anaphylaxis is survived.
Avoid some medications in patients at risk for anaphalaxis: beat blockers, ACEI.
Early Epi (before ED visit) decreases risk of hospitalization vs. late Epi (drung ED visit).
Suggested exercise: tweet the talk with hashtag #anaphylaxis
Epinephrine Training Video by FAAIS:
Anaphylaxis quiz from AAAAI
Anaphylaxis pocket card from AAAAI
Anaphylaxis action plan from FARE
Questions to ask if a patient has a suspected episode of anaphylaxis