Cardinal features of anaphylaxis

The cardinal features of anaphylaxis are:

• Itchy, urticarial rash.
• Progressive, painless swelling (angioedema) about the face and mouth, which may be preceded by itchiness, tearing, nasal congestion or facial flushing.
• Gastrointestinal symptoms, including cramps/abdominal pain and vomiting.
• Sudden reduced blood pressure or symptoms of end-organ dysfunction (e.g., hypotonia and incontinence).
• In infants, symptoms may also include fussiness, irritability, drowsiness or lethargy.