Table 1.

Causes of anaphylaxis

Immunological IgE-dependent	Immunological IgE-independent	Non-immunological	Idiopathic	Disorders which may mimic anaphylaxis
Foods (peanut, tree nut, shellfish, fish, milk, egg, soybean, peach, sesame, wheat)	Radio contrast media	Physical (exercise, cold, heat, sunlight)	Previously unrecognized allergen	Carcinoid syndrome
Stinging insects (venom)	NSAIDs	Ethanol	Mastocytosis or clonal mast cell disorders	Phaeochromcytoma
Medications (β lactam antibiotics, NSAIDs, biological agents, e.g. monoclonal antibodies)	Dextrans	Medications (e.g. opioids)		Hereditary angioedema
Natural rubber latex	Biological agents (e.g. monoclonal antibodies)			Acquired angioedema
Occupational allergens				Panic attacks
Seminal fluid
Aeroallergens
Radio contrast media

Ig = immunoglobulin; NSAID = non-steroidal anti-inflammatory drugs. [modified from Simons et al., World Allergy Organization (WAO) anaphylaxis guidelines [3]]