Table 1.

Summary of definitions

Term	Definition
Polysensitization	Sensitization (as confirmed by SPTs or ssIgE assays) to two or more allergens
Paucisensitization	Polysensitization (as confirmed by specific SPTs or ssIgE assays) to between two and four allergens.
Co-sensitization,	IgE reactivity reactions in which multiple, unrelated sensitizations arise against structurally unrelated allergen groups.
Cross-sensitization/cross-reactivity,	IgE reactivity reactions in which IgE antibodies are originally raised against one allergen and then bind to a similar protein in another allergen
Co-recognition	A subset of cross-sensitization/cross-reactivity reactions in which the initial sensitizer is not known.
Polyallergy	Clinically confirmed allergy (i.e. specific sensitization in SPTs or ssIgE assays and a causal relationship between symptoms and exposure to a specific allergen) to two or more allergens