Clinical Criteria for Diagnosing Anaphylaxis

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

 Criteria One

Acute onset of an illness with involvement of the skin, mucosal tissue, or both

(generalized urticaria, itching or flushing, swollen lips-tongue-uvula)

 +

Respiratory compromise

(dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)

or 

Reduced blood pressure or associated symptoms of end-organ dysfunction

(hypotonia, collapse, syncope, incontinence)

 OR

Criteria Two

 Two or more of the following

Occurring rapidly after exposure to a likely allergen for that patient

(minutes to several hours)

Involvement of the skin-mucosal tissue

(generalized urticaria, itch-flush, swollen lips-tongue-uvula)

Reduced blood pressure or associated symptoms

(hypotonia, collapse, syncope, incontinence)

Respiratory compromise

(dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)

Persistent gastrointestinal symptoms

(crampy abdominal pain, vomiting)

 OR

Criteria Three

 Reduced blood pressure

After exposure to known allergen for that patient

(minutes to several hours)

Infants and children:

Low systolic blood pressure (age-specific) or greater than 30% decrease in systolic blood pressure

Adults:

Systolic blood pressure of less than 90 mm Hg or greater than 30% decrease from that person’s baseline

Reference

Simons, F. E., Ebisawa, M., Sanchez-Borges, M., Thong, B. Y., Worm, M., Tanno, L. K., . . . Sheikh, A. (2015). 2015 update of the evidence base: World Allergy Organization anaphylaxis guidelines. World Allergy Organization Journal, 8(1), 1-16. doi:10.1186/s40413-015-0080-1