The usefulness of short‐course prednisolone during the initial phase of an elimination diet trial in dogs with food‐induced atopic dermatitis

Abstract

Background -Food allergy is a possible cause of atopic dermatitis (AD) in dogs; it is typically diagnosed following an eight-week elimination diet trial (EDT) and a provocation with the original diet. This lengthy procedure is difficult for owners and its interpretation may be unclear.Hypothesis/Objectives -To test the effect of prednisolone used in the first weeks of an EDT in order to reduce the total time period for diagnosis. The goal was to perform food challenges earlier than after the traditionally recommended eight weeks.Animals -Fifty-three dogs with AD were included in the study.Methods and materials -All dogs were fed a commercially available extensively hydrolyzed protein-based commercial pet food and treated with prednisolone for at least two weeks to control pruritus and inflammation. Dogs were challenged two weeks after prednisolone finished, provided that no flare had occurred. Dogs with relapsing signs were fed the hydrolyzate for at least eight weeks with or without further prednisolone treatment.Results -Ten of 53 dogs (19%) had no relapse after two weeks off prednisolone: they were subsequently challenged with their regular food, had a relapse of signs and were diagnosed with a food-induced AD within four to six weeks of starting the EDT. In the other dogs, signs remained uncontrolled without prednisolone or relapsed rapidly after its discontinuation: they were considered nonfood-allergic after an eight week EDT.Conclusion and clinical importance -This study demonstrates that a shorter EDT is possible if the allergic pruritus and inflammation are initially controlled with a short course of glucocorticoids. This shortened trial is likely to improve owner adherence and facilitate the diagnosis of food allergy.

Sensitivity and specificity of a shortened elimination diet protocol for the diagnosis of food‐induced atopic dermatitis (FIAD)

“…The positive predictive value of the diagnostic tool "one or less than one relapse" to diagnose FIAD was 100% in all groups and the negative predictive value was 95% when using prednisolone, compared to 63% positive and 100% negative predictive values when using oclacitinib. Therefore, as already discussed herein and expected by Favrot et al, 7,11 prednisolone seems to be the better option for most dogs, probably as a consequence of the more rapid and broader anti-inflammatory effects of glucocorticoids. 7 Second, we wanted to assess the influence of the initial treatment duration.…”

“…One explanation for the need of such a long period was a self‐perpetuating inflammatory process, which had to be overcome by long‐term elimination of allergen exposure 6 . A recent study showed that EDT duration could be successfully reduced by adding a short course of prednisolone in the initial EDT phase to switch off as many inflammatory pathways as possible, as soon as possible 7 …”

“…The quality of life of my dog is impaired. It is necessary to change the treatment and/or to visit the doctor” already used in the previous study 7 . This was because one of the goals of the study was to test the performance of this EDT protocol under practice conditions.…”

“…The success of an EDT depends, therefore, on the owner’s compliance and their ability to identify a recurrence of the clinical signs 6 . The interpretation of EDTs can be affected by several factors leading to false‐positive or false‐negative test results 7 . The duration of an EDT often varies yet an evidence‐based review showed that at least an eight week EDT is needed to diagnose FIAD in >90% of dogs 6 .…”

“…The duration of an EDT often varies yet an evidence‐based review showed that at least an eight week EDT is needed to diagnose FIAD in >90% of dogs 6 . A recent study demonstrated that a shorter EDT is possible if the initial allergic pruritus and inflammation are controlled with a short course of glucocorticoids 7 . The authors proposed that the shortened trial is likely to improve owner compliance and facilitate the diagnosis of food allergy.…”