Results of allergen-specific immunotherapy in atopic dogs with Malassezia hypersensitivity: a retrospective study of 16 cases.

Background - Hypersensitivity reactions to Malassezia spp have been shown to occur in dogs with atopic dermatitis (AD) and to cause exacerbation of clinical signs. Improvement of clinical signs following use of antifungal medication is seen with both Malassezia overgrowth or Malassezia hypersensitivity (MHS). Subcutaneous immunotherapy (SCIT) is considered a safe and effective treatment for management of canine AD. Adverse effects are considered rare. Objectives - To report on the use of SCIT with Malassezia extracts in mono-sensitized dogs. Animals - Sixteen client owned dogs diagnosed with MHS and treated with SCIT. Methods - A retrospective review of medical records of atopic dogs diagnosed with MHS, mono-sensitized for Malassezia allergens on intradermal test and treated with SCIT for more than 10 months. Efficacy was measured by decreasing use of anti-inflammatory and antifungal medication by >= 50% and by decreasing pruritus by >= 50% as assessed by owners, using a pruritus score. Results - Good response to SCIT was seen in nine of 16 cases (56%) with both a reduction in use of anti-inflammatory and antifungal medication as well as a reduction in pruritus scores by >= 50%. No adverse effects were reported. Conclusion - Allergen-specific immunotherapy was a safe treatment for dogs with Malassezia hypersensitivity. The efficacy of Malassezia immunotherapy corresponds well to the results of previous studies of immunotherapy with other environmental allergens.