Panallergen

Allergen that is ubiquitous or occurs in numerous allergen sources. This means that the same IgE molecule can bind to different allergens (antigens) that carry the same epitope.

Often panallergens are evolutionarily highly conserved allergens (their structure has hardly changed over evolution). This "structural fidelity" explains many unexpected cross-reactions.

Examples of panallergens are profilins or tropomyosins.

Many allergens, especially from plant sources, are glycoproteins and often cause cross-reactivity. For this reason, the term "cross-reactive carbohydrate determinants" was also coined CCD. Such glycoepitopes contribute to the fact that allergens also have common features outside phylogenetically related protein families.