First report of angio-oedema subsequent to the administration of allergen specific sublingual immunotherapy for the management of equine hypersensitivity dermatitis.

BACKGROUND

Sublingual immunotherapy (SLIT) offers an alternative mode of allergen delivery to subcutaneous immunotherapy (SCIT) with the aim of inducing immunological tolerance. Currently, there are no published reports regarding the efficacy or safety of SLIT in horses.

HYPOTHESIS/

OBJECTIVE

To describe the first case of several adverse events occurring in a horse subsequent to the repeat administration of SLIT.

ANIMAL: A seven-year-old, warmblood mare with a confirmed diagnosis of equine hypersensitivity dermatitis (EHD).

METHODS AND

RESULTS

Immunotherapy was recommended for management of EHD. Due to the temperament of the horse, the owner elected to proceed with SLIT. Thirty six hours after commencing SLIT, the mare developed scleral oedema, moderate dyspnoea and abdominal discomfort. SLIT was withdrawn for 10 days and re instituted using a ten-fold dilution of the original vaccine. Localized oedema and swelling of the tongue developed within 12 h of administration. At this juncture, SLIT was withdrawn. The horse was rechallenged with the SLIT allergen vehicle, 50% glycerine and no adverse reactions occurred. SCIT was commenced using the same allergens and no adverse events occurred with repeated administration.

CONCLUSIONS AND CLINICAL

IMPORTANCE

To the best of the authors' knowledge, this is the first reported case of adverse reactions developing subsequent to the administration of SLIT for the management of EHD.