Human Allergy to Cats and Dogs: Molecular and Environmental Determinants, Diagnosis, and Precision Management

Abstract

Simple Summary Cats and dogs release allergenic proteins from saliva, skin-associated secretions, dander, urine, and other biological materials. These proteins can be transported on airborne particles and dust, including into buildings without resident animals. Exposure alone, however, does not mean that a person will become sensitized or develop allergic disease. Clinical allergy depends on the interaction between the relevant allergen molecules, the amount and pattern of exposure, allergen-specific IgE, host susceptibility, and the affected organ system. This review summarizes the major cat and dog allergen molecules, how they are carried through indoor environments, the immune mechanisms that lead from sensitization to symptoms, and the strengths and limitations of current diagnostic and management approaches. Particular attention is given to component-resolved diagnosis, cross-reactivity, allergen immunotherapy, environmental control, and emerging allergen-neutralizing strategies. The review emphasizes that molecular sensitization results must be interpreted together with exposure history and clinical symptoms before a causal allergen is assigned.