Table 2.

Clinical criteria for the diagnosis of anaphylaxis, proposed at the Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network (NIAID/FAAN) symposium, 2005.

Anaphylaxis is highly likely when any one of the following 3 criteria are fulfilled:

1.
Acute onset of an illness (minutes to several hours) with involvement of the skin, mucosal tissue, or both (eg, generalized hives, pruritus or flushing, swollen lips-tongue-uvula)
- AND AT LEAST ONE OF THE FOLLOWING
- a.
  Respiratory compromise (eg, dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)
- b.
  Reduced BP or associated symptoms of end-organ dysfunction (eg, hypotonia (collapse], syncope, incontinence)
2.
Two or more of the following that occur rapidly after expo sun; to a likely allergen for that patient (minutes to several hours):
- a.
  Involvement of the skin-mucosal tissue (eg, generalized hives, itch-flush, swollen lips-tongue-uvula)
- b.
  Respiratory compromise (eg, dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)
- c.
  Reduced BP or associated symptoms (eg, hypotonia [collapse], syncope, incontinence)
- d.
  Persistent gastrointestinal symptoms (eg, crampy abdominal pain, vomiting)
3.
Reduced BP after exposure to known allergen for that patient (minutes to several hours):
- a.
  Infants and children: low systolic BP (age specific) or greater than 30% decrease in systolic BP^a
- b.
  Adults: systolic BP of less than 90 mm Hg or greater than 30% decrease from that person's baseline

PEF,Peak expiratory flow; BP, blood pressure.

Low systolic blood pressure for children is defined as less than 70 mm Hg from 1 month to 1 year, less than (70 mm Hg + [2 × age]) from 1 to 10 years, and less than 90 mm Hg from 11 to 17 years