Homologous allergens: A regulatory and clinical perspective

The last decade has ushered new data on the allergenic molecules. Allergens from identical protein families are now known to be present in different allergen sources and are labeled as homologous allergens. An important fact for such allergens is that they may be present among different sources, and their presence is not conditional to taxonomical relationship. These allergenic molecules express sequence identity and clinical cross‐reactivity. This principle of homologous allergens was brought forward by Lorenz et al.[1] They also suggested that “classification of allergen sources in one homologous group on the basis of homology and cross‐reactivity of allergens is more specific and satisfactory than mere taxonomic relationship.”[1]