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. 2010 Dec;11(5):456–461.

Table 1.

Clinical criteria for diagnosing anaphylaxis

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

  1. Acute onset of an illness (minutes to several hours) with involvement of the skin, mucosal tissue, or both (e.g. generalized hives, pruritus or flushing, swollen lips-tongue-uvula)

    AND AT LEAST ONE OF THE FOLLOWING

    1. Respiratory compromise (e.g. dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)

    2. Reduced BP or associated symptoms of end- organ dysfunction (e.g. hypotonia [collapse], syncope, incontinence)

  2. Two or more of the following that occur rapidly after exposure to a likely allergen for that patient (minutes to several hours):

    1. Involvement of the skin-mucosal tissue (e.g. generalized hives, itch-flush, swollen lips-tongue-uvula)

    2. Respiratory compromise (e.g. dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)

    3. Reduced BP or associated symptoms (e.g. hypotonia [collapse], syncope, incontinence)

    4. Persistent gastrointestinal symptoms (e.g. crampy abdominal pain, vomiting)

  3. Reduced BP after exposure to known allergen for that patient (minutes to several hours):

    1. Infants and children: low systolic BP (age specific) or greater than 30% decrease in systolic BP*

    2. 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 one month to one year, less than (70 mm Hg + [2 times age]) from one to ten years, and less than 90 mm Hg from 11 to 17 years.1