[Respiratory allergies: current data]

Over the last decade, advances in our knowledge of allergens and in methods for determining their structure have given the clinician a molecular rather than macroscopic view of allergy. The prevalence of sensitization to different allergenic molecules is known for the principal pneumallergens. This knowledge is crucial for understanding the cross reactions between respiratory allergens. The main cross reactions are described here for pollen, mites, roaches, and mammals. In addition, the biological function of a certain number of respiratory allergens are known. Allergens with an enzymatic function, allergens with a transport function, allergens implicated in the regulation of muscle contraction, and allergens participating in the protein defense system have been identified. Potential factors underlying the allergenicity of airborne allergens are discussed: physical properties, structures, biological functions. The diversity of biological functions prohibits retaining a single specific function as a prerequisite for allergenicity; certain major allergens do not have a defined function. No structural form appears to be incompatible with the allergenic potential of a protein found in the environment.