Anti-inflammatory and anti-pruritic therapy in canine atopy

Successful management of atopic dermatitis often requires sustained therapy to prevent recurrence of the clinical signs and to minimize long-term changes to the skin; this paper offers a brief overview of the current options available.

Introduction

Treatment of canine atopic dermatitis (AD) involves two phases. The initial control of the inflammation and pruritus must be followed by ongoing proactive management to maintain remission and prevent chronic changes. Anti-inflammatory and anti-pruritic options with good evidence of high efficacy include topical and systemic glucorticoids, ciclosporin, oclacitinib and lokivetmab, and clinical judgement is required to select the optimal treatment for each dog (Figure 1).
 

Topical and systemic glucocorticoids have potent, broad-spectrum and rapid activity against most cells, tissues and mediators involved in inflammation, and are ideal for initial control of inflammation and pruritus. It is generally safe to use short- and long-term topical steroids, particularly with the more reliable and well-tolerated products (e.g., hydrocortisone aceponate) and/or local treatment of the eyes, ears and feet. There is a greater risk of adverse effects with long-term systemic treatment.

Ciclosporin mainly targets lymphocytes; it therefore has potent and broad-spectrum anti-inflammatory activity, but resolution of lesions and pruritus will be slower than with other agents. More rapid remission can be achieved by initially combing ciclosporin with glucocorticoids, oclacitinib or lokivetmab. However, long-term combination treatment with broad-spectrum anti-inflammatory drugs should be avoided because of the risk of immunosuppression.

Oclacitinib is a Janus Kinase (JAK) 1 inhibitor that particularly blocks activity of IL-31, a key cytokine involved in pruritus and acute inflammation. Treatment every 12 hours results in very rapid control of pruritus, although this may recur when dogs are switched to once-daily therapy. Dogs should be carefully monitored for bacterial, fungal or parasitic infections and any non-selective effects (anemia, neutropenia, raised liver enzymes, elevated bile acids and weight gain). There are also reports of viral papillomas with neoplastic transformation to squamous cell carcinoma in situ (Bowen’s disease) and/or invasive squamous cell carcinoma.

Lokivetmab is a caninized monoclonal anti IL-31 antibody that specifically binds to and neutralizes circulating IL-31. It is fast acting and well tolerated, with little to no interaction with other medications or vaccines. Long-term safety is unknown but it is likely to be very good. Lokivetmab is administered by injection and is ideal for dogs that are hard to medicate orally and/or have concurrent conditions and treatments that preclude other medication. It offers rapid relief from pruritus and can also be combined with broad-spectrum agents. [...]