Anaphylaxis algorithm.
Anaphylaxis is a severe, life-threatening, generalised or systemic hypersensitivity reaction.
Incidence rate: 30 - 950 cases per 100,000 persons per year. It is important to note that, in many cases, no cause can be identified. A significant number of cases of anaphylaxis are idiopathic (non-IgE mediated).
Anaphylaxis is likely when all of the following 3 criteria are met:
- Sudden onset and rapid progression of symptoms
- Life-threatening Airway and/or Breathing and/or Circulation problems
- Skin and/or mucosal changes (flushing, urticaria, angioedema)
The following supports the diagnosis:
- Exposure to a known allergen for the patient
Remember:
- Skin or mucosal changes alone are not a sign of an anaphylactic reaction
- Skin and mucosal changes can be subtle or absent in up to 20% ofreactions (some patients can have only a decrease in blood pressure, i.e., a Circulation problems)
- There can also be gastrointestinal symptoms (e.g. vomiting, abdominal pain, incontinence)
The most common triggers are (according to "Pumphrey RS. Fatal anaphylaxis in the UK, 1992-2001.") :
- Domestic triggers:
Stings
|
47
|
29 wasp, 4 bee, 14 unknown
|
Nuts
|
32
|
10 peanut, 6 walnut, 2 almond, 2 brazil, 1 hazel,
11 mixed or unknown
|
Food
|
13
|
5 milk, 2 fish, 2 chickpea, 2 crustacean, 1 banana,
1 snail
|
Food possible cause
|
17
|
5 during meal, 3 milk, 3 nut, 1 each - fish, yeast, sherbet, nectarine, grape, strawberry
|
Other
|
3
|
1 latex, 1 hair dye, 1 hydatid
|
- Medical triggers:
Antibiotics
|
27
|
11 penicillin, 12 cephalosporin, 2 amphotericin,
1 ciprofloxacin, 1 vancomycin
|
Anaesthetic drugs
|
39
|
19 suxamethonium, 7 vecuronium, 6 atracurium,7 at induction
|
Other drugs
|
24
|
6 NSAID, 3 ACEI, 5 gelatins, 2 protamine, 2 vitamin K, 1 each - etoposide, acetazolamide,pethidine, local anaesthetic, diamorphine, streptokinase
|
Contrast media
|
11
|
9 iodinated, 1 technetium, 1 fluorescein
|
Anaphylaxis algorithm:
(click to enlarge or download)
According to Resuscitation Council (UK)