Uses
Alone
- Identify potentially important allergens in order to start immunotherapy once a diagnosis of atopy
has been made.
In combination
- Diagnosis of atopy in dogs with compatible history, clinical signs and laboratory tests that do not support other differential diagnoses.
- Identification of allergens involved in atopy for desensitizing vaccine production.
- To identify allergens involved in atopy before attempting specific avoidance (however avoidance is rarely practical in dogs).
Other points
Only undertake intradermal testing if animal owner is willing to commit to at least 1 year of hyposensitization treatment if test confirms diagnosis of atopy
Result data
Normal (reference) values
- Generally: a wheal less than the mean of those produced by positive and negative controls is considered negative.
- Subjective considerations include: induration, erythema and steepness of the wall of the wheal.
- Completely negative results usually occur when a tentative diagnosis of atopy was incorrect.
Abnormal values
- Generally: a wheal >the mean of those produced by positive and negative controls is considered positive.
- Subjective considerations include: induration, erythema and steepness of the wall of the wheal.
- A positive intradermal skin test is one in which there are positive reactions to allergens that are compatible with the patient's history and seasonality of pruritus (may only include house dust mites).
Errors and Artifacts
- Drug interference, eg antihistamies, glucocorticoids.
- Irritable, inflamed or traumatized skin.
- Stress, pregnancy and serious internal disease.
- Testing at the wrong time of year.
- Poor skin test technique.
- Outdated extract.
Sources
Publications
Refereed papers
- Mueller R S, Bettenay S V & Tideman L (2000) Aero-allergens in canine atopic dermatitis in southeastern Australia based on 1000 intradermal skin tests. Aust Vet J 78 , 392-399.
- Codner E C & Lessard P (1993) Comparison of intradermal allergy test and enzyme-linked immunosorbent assay in dogs with allergic skin disease. JAVMA 202 , 739.
Other sources of information
- Moriello K A & Mason I S (1995) Eds Handbook of Small Animal Dermatology. 1st edn. Pergamon. pp 33-36. (Concise step-by-step procedure.)
- Scott D W, Miller W H, Griffin C E (1995) Eds Muller and Kirk's Small Animal Dermatology. 5th edn. Philadelphia: WB Saunders Co. (Concise step-by-step procedure).
- Sousa C A & Norton A L (1990) Advances in methodology for diagnosis of allergic skin disease. Vet Clin North Am Small Anim Pract 20 , 1419-1427.
- Reedy L M & Miller W H (1989) Allergic skin diseases of dogs and cats. 1st edn. Philadelphia: W B Saunders. pp 81-109. (Detailed procedure and interpretation.)
