References
Atopic dermatitis
Abstract
Canine atopic dermatitis (CAD) is a common genetically predisposed inflammatory and pruritic disease. CAD is a diagnosis made by the exclusion of other pruritic skin diseases such as ectoparasites, and other allergies such as flea bite hypersensitivity, and cutaneous adverse food reaction. Nurses can play an important part in helping to investigate the underlying causes of pruritus in dogs, it is therefore important they have a good working knowledge of the clinical presentation of this common disease and the appropriate diagnostic tests that are routinely used to help rule out other causes of pruritus. Therapy can include systemic medication such as essential fatty acids, antihistamines, glucocorticoids, ciclosporine, Janus kinase inhibitors, monoclonal antibodies to IL31 and allergen specific immunotherapy.
Canine atopic dermatitis (CAD) is a common genetically predisposed inflammatory and pruritic skin disease. It is associated most commonly with IgE antibodies to environmental allergens (Halliwell and DeBoer, 2001). The clinical presentations of CAD are protean and vary between breeds. The extent of the lesions, the chronicity of the disease, the type of secondary infection as well as the overlap of clinical signs with other non-atopic skin diseases can make diagnosis challenging (Hensel et al, 2015).
A consistent finding in CAD is the presence of pruritus (itching). Pruritus can manifest itself in a variety of ways including licking, chewing, scratching, rubbing or over grooming, all of which can lead to signs of self-inflicted trauma and chronic changes in the skin. Clinical signs in the early stages of the disease are often seasonal. In the UK dogs commonly present with pollen-induced disease in the early summer often going into remission at the end of the pollen season in the autumn. Some dogs will continue with a seasonal pattern, but many will go on to develop perennial disease with seasonal exacerbation. The areas of the dog's body that are most commonly affected are the face (Figure 1), concave aspect of the ear pinna, ventrum, axilla, inguinal area, perineal area and distal extremities (Figure 2) (Griffin and DeBoer, 2001). Primary lesions such as papules, which are common and a useful differentiator in such diseases as ectoparasites, are uncommon in CAD. Often dogs present with erythema, and lesions are created by the dogs as they self-traumatize due to the pruritus. In chronic disease lesions can become hyperpigmented, lichenified and excoriated and often become much more extensive to extend beyond the classical sites associated with CAD (Figure 3). A set of clinical criteria developed by Favrot (2010) are useful to try to differentiate cases of CAD from other pruritic skin disease (Favrot et al, 2010). These are best applied after ectoparasites, infection and other allergic diseases have been eliminated (Table 1).
Register now to continue reading
Thank you for visiting The Veterinary Nurse and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.