Changes

Routine haematology and biochemistry rarely show any abnormalities in dogs, but eosinophilia is often seen in cats¹. The measurement of total serum IgE levels is not useful in the diagnosis of atopic dermatitis as IgE levels do not significantly differ betweem atopic and normal animals^beale. IgE levels are also influence by the presence of parasites, vaccinations and breed, and so this test is not reliable

Routine haematology and biochemistry rarely show any abnormalities in dogs, but eosinophilia is often seen in cats¹. The measurement of total serum IgE levels is not useful in the diagnosis of atopic dermatitis as IgE levels do not significantly differ betweem atopic and normal animals^beale. IgE levels are also influence by the presence of parasites, vaccinations and breed, and so this test is not reliable

Allergen-specific IgE tests are only useful when a diagnosis of atopic dermatitis has already been reached by consideration of histoty and clinical exam, and by ruling out other causes of pruritus. The test is used to identify allergens for immunotherapy by evaluating serum levels of IgE specific for a variety allergens. The exact technique varies between laboratories, but the principle is the same: Ser The unreacted antibodies are washed away, and then the allergen-bound antibody is detected using an IgE specific reagent (coupled to an enzyme or radioisotope). The IgE bound reagent is then quantified which should be proportional to the amount of allergen-specific IgE. Measurement depends on the assay utilized, but may use radiometric, fluorometric, or colorimetric measures.

Allergen-specific IgE tests are only useful when a diagnosis of atopic dermatitis has already been reached by consideration of histoty and clinical exam, and by ruling out other causes of pruritus. The test is used to identify allergens for immunotherapy by evaluating serum levels of IgE specific for a variety allergens. The exact technique varies between laboratories, but the principle is the same: serum is allowed to react with the allergen before excess serum and antibodies are rinsed away. An IgE-specific reagent linked to an indicator is added, and the amount that binds is proportional to the amount of allergen-sprecific IgE^beale. This can then be quantified. Several factors can adversely influence the test results. These include age, season, use of corticosteroids and laboratory inaccuracies.

 

Besides laboratory inaccuracies, there are other factors which may influence test results: age, season during which the patient is tested, prior or current corticosteroid therapy.

===Other Tests===

===Other Tests===