The search for still unknown pathomechanisms of allergy

Abstract

In recent decades, atopic diseases, such as atopic dermatitis (AD), allergic asthma (AA), allergic rhinitis (AR), and food allergy (FA) have been estimated rapidly increasing in prevalence. These diseases are characterized by the presence of specific immunoglobulin E (sIgE) and often relate to each other and develop in sequence (the so-called “atopic march”). AD may be the first early manifestation in infants followed by FA often within the first year of life. Moreover, AD is a risk factor for developing sensitization to airborne allergens later in life that can cause clinical manifestations of AA and AR. According to the dual-allergen exposure hypothesis, allergic sensitization to food allergens is promoted through cutaneous exposure, rather than the oral route. Moreover, there is evidence that exposure to food allergens, in particular peanuts, in the airway would also lead to food sensitization. The most frequent route of sensitization for inhalant allergens is still debated. Of note, a recent case report supports the development of sensitization to cat dander through a cat bite. Our review aims to provide an overview of current knowledge and unmet needs in the pathophysiology of respiratory and FAs.