How long to stop allergy meds before dog allergy tests

Abstract

BACKGROUND: Anti-allergic drugs (e.g. antihistamines, glucocorticoids and ciclosporin) are often administered to dogs with atopic dermatitis to relieve pruritus and skin lesions. Allergen-specific intradermal tests (IDT) and allergen-specific IgE serological (ASIS) tests are used to characterize the allergens to which dogs are hypersensitive. Anti-allergic drugs have the potential to influence the results or interpretation of these tests. OBJECTIVES: To provide evidence-based recommendations for anti-allergic drug withdrawal times before IDT and ASIS tests. METHODS: Three citation databases and abstracts from international meetings were searched for relevant studies. Studies were grouped based on similar interventions and types of tests. Withdrawal times for each type of drug and test were then extrapolated from the study results. RESULTS: Before the assessment of immediate reactions to IDT, proposed optimal withdrawal times for antihistamines, oral glucocorticoids, topical/otic glucocorticoids and ciclosporin are 7, 14, 14 and 0 days, respectively. Studies have provided no evidence for drug withdrawal prior to ASIS tests for oral ciclosporin or prednisone/prednisolone. Owing to a lack of studies, recommendations for withdrawal times before ASIS tests cannot be made for topical glucocorticoids and antihistamines. CONCLUSIONS AND CLINICAL IMPORTANCE: These proposed withdrawal times are based on the existing evidence at the end of 2011. Care must be taken before extrapolating the suggested withdrawal times to other species, higher dosages, different formulations and/or durations of administration of tested drugs, as well as to other medications from the same category.