Presentation	Differential diagnosis
Hypotension	Septic shock
	Vasovagal reaction
	Cardiogenic shock
	Hypovolemic shock
Respiratory distress with wheezing or stridor	Airway foreign body
	Asthma and chronic obstructive pulmonary disease exacerbation
	Vocal chord dysfunction syndrome
Postprandial collapse	Airway foreign body
	Monosodium glutamate ingestion
	Sulfite ingestion
	Scombroid fish poisoning
Flush syndrome	Carcinoid
	Postmenopausal hot flushes
	Red man syndrome (vancomycin [Vancocin])
Miscellaneous	Panic attacks
	Systemic mastocytosis
	Hereditary angioedema
	Leukemia with excess histamine production