Dermatological Disorders

Important Nutritional Considerations in Management of Atopic Dermatitis

Domenico Santoro   
DVM, DrSc, MS, PhD, DACVD, DECVD, DACVM  
University of Florida  
Gainesville, Florida, USA

Q. How is canine atopic dermatitis defined?

A. According to the new definition of canine atopic dermatitis by the International Committee on Allergic Diseases of Animals, “canine atopic dermatitis is a hereditary, typically pruritic and predominantly T-cell driven inflammatory skin disease involving interplay between skin barrier abnormalities, allergen sensitization and microbial dysbiosis.”¹ This new definition incorporates the alteration of the cutaneous microbiome (dysbiosis) as well as skin barrier abnormalities as integral components of the disease. Atopic dermatitis is a very frustrating skin disease characterized by recurrent flares and the need for long-term use of topical and systemic medications. 

Q. Why is nutrition important in the management of canine atopic dermatitis?

A. The lack of complete resolution and the need of constant medications to manage the clinical signs has been associated with financial and psychological fatigue by the owners. For these reasons an early and appropriate diagnosis and an optimal, multifaceted approach, including diet as well as topical and systemic medications, are essential for the effective management of this disease. In the past decade, the use of diets specifically designed to improve the quality of the skin barrier and reduce clinical signs associated with atopic dermatitis has significantly increased. Diets have become an integral component of the therapeutic plan for allergic dogs with the ultimate goal to reduce the need for anti-inflammatory/antipruritic medications potentially associated with high cost and/or side effects. Common nutrients in such diets associated with beneficial effects on canine atopic dermatitis include essential fatty acids (specifically eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA], as well as linoleic acid [LA], alpha-linolenic acid [ALA], and gamma-linolenic acid [GLA]), vitamin A, vitamin B (niacin and pantothenic acid in particular), vitamin E, as well as zinc.²

Q. How do these nutrients help patients with atopic dermatitis?

A. Vitamins and minerals are essential for the integrity of the skin barrier by regulating the production of sebum and the epidermal differentiation and cornification process. Essential fatty acids have been considered specifically for their anti-inflammatory properties. Diets have been seen as a consistently higher and more reliable source of essential fatty acids than oral supplementations.³ Over the years, several studies have been published on the benefits of specific diets for the management of canine atopic dermatitis with most of these diets being rich in essential fatty acids and other nutrients.^4–8 

Q. Why do dermatologists feel use of diets formulated for atopic dermatitis are important in the management of these cases?

A. Skin-specific diets have been looked at with more interest by the dermatology community for their usefulness in managing the clinical signs and intestinal dysbiosis present in atopic dogs. Such beneficial effects are not only due to their high content in essential fatty acids, but also in micronutrients and vitamins capable of restoring the integrity of the skin barrier. The beneficial effects of these diets may provide an important synergistic effect with the current, most commonly used therapeutics for atopic dermatitis. Therefore, it is important to consider a diet component in the management of canine atopic dermatitis. For cases with food allergy and atopic dermatitis, nutrition may also play a further role in the management of clinical signs.

Q. What is the potential role of the microbiome in canine atopic dermatitis? 

A. Atopic dermatitis is a systemic disease often associated with intestinal and cutaneous dysbiosis. The relevance of microbial dysbiosis in the pathogenesis of canine atopic dermatitis is still unclear. However, the detrimental impact of dysbiosis on immune tolerance and exacerbation of atopic symptoms is very clear.⁹

1. Eisenschenk, M. C., Hensel, P., Saridomichelakis, M. N., Tamamoto-Mochizuki, C., Pucheu-Haston, C. M., & Santoro, D. (2024). Introduction to the ICADA 2023 canine atopic dermatitis pathogenesis review articles and updated definition. Veterinary Dermatology, 35, 3-4. doi: 10.1111/vde.13183
2. Shmalberg, J. (2017). Diets and the dermis: Nutritional considerations in dermatology. ACVN Nutrition Notes. Today's Veterinary Practice, 7, 33-42.
3. Martinez, N., & McDonald, B. (2021). A study into the fatty acid content of selected veterinary diets, supplements and fish oil capsules in Australia. Veterinary Dermatology, 32(3), 256-e69. doi: 10.1111/vde.12950
4. Glos, K., Linek, M., Loewenstein, C., Mayer, U., & Mueller, R. S. (2008). The efficacy of commercially available veterinary diets recommended for dogs with atopic dermatitis. Veterinary Dermatology, 19(5), 280-287. doi: 10.1111/j.1365-3164.2008.00688.x
5. Watson, A., Rostaher, A., Fischer, N. M., & Favrot, C. (2022). A novel therapeutic diet can significantly reduce the medication score and pruritus of dogs with atopic dermatitis during a nine-month controlled study. Veterinary Dermatology, 33(1), 55-e18. doi: 10.1111/vde.13020
6. van Beeck, F. L., Watson, A., Bos, M., Biourge, V., & Willemse, T. (2015). The effect of long-term feeding of skin barrier-fortified diets on the owner-assessed incidence of atopic dermatitis symptoms in Labrador retrievers. Journal of Nutritional Science, 12(4), e5. doi: 10.1017/jns.2014.61
7. Guidi, E. E. A., Gramenzi, A., Persico, P., Di Prinzio, R., Di Simone, D., & Cornegliani, L. (2021). Effects of feeding a hypoallergenic diet with a nutraceutical on fecal dysbiosis index and clinical manifestations of canine atopic dermatitis. Animals (Basel), 11(10), 2985. doi: 10.3390/ani11102985
8. Noli, C., Varina, A., Barbieri, C., Pirola, A., & Olivero, D. (2023). Analysis of intestinal microbiota and metabolic pathways before and after a 2-month-long hydrolyzed fish and rice starch hypoallergenic diet trial in pruritic dogs. Veterinary Sciences, 10(7), 478. doi: 10.3390/vetsci10070478
9. Craig, J. M. (2016). Atopic dermatitis and the intestinal microbiota in humans and dogs. Veterinary Medicine and Science, 2, 95-105. doi: 10.1002/vms3.24