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→Other Tests
===Other Tests===
===Other Tests===
Intradermal skin tests determine the ability of allergens injected intradermally to cause mast cell degranulation leading to a subsequent wheal and flare reaction. It is therefore a close approximation of the pathogenesis of atopic dermatitis, and is a useful tests for revealing specific allergens for use in immunotherapy. Aqueous allergens are used for testing and include such things as house dust mites, pollens, moulds, insects and epidermal antigens. These should be stored in the fridge to maintain potency, and allowed to reach room temperature before testing<sup>2</sup>. Test results can be affected or inhibited by numerous factors such as medications, sedatives and stress. Drugs shown to affect intradermal skin testing include antihistamines, tricyclic antidepressants and glucocorticoids. Withdrawal times of 2, 4 and 8 weeks have been suggested for topical, oral and long-acting injectable steroids respectively, although this may be diffcult in a very pruritic animal. Some animals require sedation for intradermal skin testing and xylazine and medetomidine have been shown not to affect results. Diazepam and acepromzine should not be used<sup>2</sup>.
Intradermal skin tests determine the ability of allergens injected intradermally to cause mast cell degranulation leading to a subsequent wheal and flare reaction. It is therefore a close approximation of the pathogenesis of atopic dermatitis, and is a useful tests for revealing specific allergens for use in immunotherapy. Aqueous allergens are used for testing and include such things as house dust mites, pollens, moulds, insects and epidermal antigens. These should be stored in the fridge to maintain potency, and allowed to reach room temperature before testing<sup>2</sup>. Test results can be affected or inhibited by numerous factors such as medications, sedatives and stress. Drugs shown to affect intradermal skin testing include antihistamines, tricyclic antidepressants and glucocorticoids. Withdrawal times of 2, 4 and 6 weeks have been suggested for topical, oral and long-acting injectable steroids respectively<sup>4</sup>, although this may be diffcult in a very pruritic animal. Some animals require sedation for intradermal skin testing and xylazine and medetomidine have been shown not to affect results. Diazepam and acepromzine should not be used<sup>2</sup>.
Fine needles are used to inject allergen intradermally. Histamine is used as a positive control, and isotonic saline as a negative. Approximately 0.05-1.0 ml solution is injected at each site, and after around 15 minues the test is read by scoring each allergen based on the size of the bleb.
===Biopsy===
===Biopsy===