Final answer:
1. In Canine Atopic Dermatitis (cAD), a percentage of cases, approximately 10-20%, have no detectable allergen-specific IgE.
Step-by-step explanation:
Canine Atopic Dermatitis (cAD) is a hypersensitivity disorder in dogs that is comparable to human atopic dermatitis. It is an allergic skin disease that can be triggered by various environmental allergens. In a subset of cAD cases, approximately 10-20%, no detectable allergen-specific IgE can be identified.
IgE (Immunoglobulin E) is an antibody associated with allergic reactions, and its specific form, allergen-specific IgE, is often measured to identify the allergens responsible for hypersensitivity reactions. However, in a notable proportion of cAD cases, standard tests may not reveal specific IgE antibodies to known allergens. This phenomenon may be attributed to limitations in current diagnostic methods or the presence of other immune mechanisms involved in the dermatitis.
Understanding the cases of cAD with no detectable allergen-specific IgE is essential for accurate diagnosis and treatment planning. The absence of identifiable IgE may indicate the involvement of non-IgE-mediated immune responses or the presence of unknown allergens.
This underscores the complexity of hypersensitivity disorders in dogs and emphasizes the need for comprehensive diagnostic approaches to address the diverse immunological factors contributing to cAD.