Box 3.

Allergic diseases in which the route of sensitization is not the same as the route of exposure giving symptoms

Allergic Syndrome	Presentation	Route of Sensitization	Mechanism
Oral Allergy Syndrome	Oral symptoms to apple, cherries, hazelnut, etc.	Sensitization to inhaled pollen, e.g. birch	Cross-reactivity between Bet v 1 and major allergens, e.g. Mal d 1, Pru av 1, Cor a 1, etc.
Pork/Cat Syndrome	Oral symptoms and anaphylaxis to pork	Sensitization to cat albumin (Fel d 2)	Cross-reactivity between albumins of cat and pork
Peanut Allergy	Anaphylactic reactions to oral peanut	Sensitization through the skin in patients with a filaggrin defect	Sensitization to Ara h 1 and Ara h 2
Delayed Anaphylaxis to Red Meat	Delayed urticarial and anaphylactic reactions to red meat	Sensitization to alpha-gal from tick bites	Sensitization to mammalian oligosaccharide galactose-alpha-1,3-galactose