Acknowledgements
This study was funded by Centre for Interdisciplinary Research in Animal Health (CIISA, Lisbon, Portugal: UIDB/00276/2020), Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS, Portugal: LA/P/0059/2020) and Fundação para a Ciência e a Tecnologia (FCT, Lisbon, Portugal: PhD individual grant UI/BD/153072/2022 to Marta Pinto; UIDB/04138/2020 and UIDP/04138/2020 to iMed.ULisboa; CEECINST/00145/2018 to Joana Marto), to whom the authors are grateful. The authors also thank LETIPharma S.L.U. (Barcelona, Spain) for supporting this study, Nuno Ferreira for designing the 3D patch prototype, and the owners of healthy and atopic dogs for participating in this study.
Conflicts of interest: None declared.
ABSTRACT: 248 words
Background – Allergen immunotherapy is a well-established treatment for canine atopic dermatitis (CAD), but non-invasive, safe, effective, and easy-to-use home-administration routes that promote owner’s compliance are needed. Epicutaneous immunotherapy (EPIT) has been suggested as a promising alternative treatment for human allergies. This study primarily evaluated EPIT’s feasibility, effectiveness, and safety for CAD.
Methods – Sixteen client-owned dogs with spontaneous, nonseasonal, mite-sensitive CAD were enrolled for a 6-month, once-weekly, 12-hour EPIT. A costume-made 3D-printed device was designed to deliver the allergen-based formulation. Primary efficacy outcomes included the owner’s assessed pruritus (PVAS10) and treatment efficacy (OGATE), and veterinarian-assessed skin lesions (2D-IGA). Secondary efficacy outcomes were the quality-of-life (QoL) and serological allergen-specific IgE’s concentrations. Effectiveness was defined by the success of the primary efficacy outcomes, according to the ICADA’s COSCAD’18 recommendations. EPIT was deemed safe in the absence of severe side-effects.
Results – EPIT effectively improved clinical condition, with a success rate of 73.3% for pruritus, 66.7% for skin lesions, and 93.3% for QoL. A good-to-excellent response to EPIT was rated by 93.3% of owners in OGATE. EPIT significantly improved PVAS10 (p=0.000015), 2D-IGA (p=0.006) and QoL (p=0.000014) scores over six months. A significant difference was evident within one month for PVAS10 (p=0.003) and 2D-IGA (p=0.009) scores. Seven dogs partially desensitised to at least one mite and two fully desensitised to all mites after six months. Severe adverse events were not recorded.
Conclusions – This pioneer study emphasises EPIT’s potential as a novel and promising, non-invasive, feasible, effective, safe, and well-tolerated CAD treatment, supporting further investigation.
Keywords: Allergen immunotherapy; atopic dermatitis; canine; epicutaneous immunotherapy (EPIT); vaccine.
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