Table 5

 Symptoms and signs of anaphylaxis with differential diagnosis(es)

Symptom/signs of anaphylaxisDifferential diagnosis(es)
Respiratory compromise (shortness of breath, wheeze, stridor)Asthma, COPD, inhaled foreign body, pulmonary embolism
Loss of consciousness (LOC)Vasovagal reaction, seizures, cardiac event (for example, arrhythmia)
HypotensionVasovagal reaction, shock (cardiogenic/septic/hypovolaemic)
CollapseAs for hypotension/LOC plus panic attack, hyperventilation syndrome, Munchausen’s syndrome
Cutaneous skin flushingVasovagal reaction, carcinoid syndrome, postmenopausal flushing
Gastrointestinal (diarrhoea, abdominal cramps, nausea, and vomiting)Hereditary angio-neurotic oedema (HANE), food poisoning