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

Abstract

Background -The gold standard to diagnose food allergy in dogs is an eight week elimination diet trial (EDT) followed by a re-challenge. A recent study demonstrated that a shorter EDT is possible if prednisolone is administered initially.Hypothesis/Objectives -The goal was to evaluate the sensitivity and specificity of the EDT based on the number of relapses after prednisolone discontinuation. In addition, the aim was to determine whether the initial treatment length or the replacement of prednisolone with oclacitinib would influence the outcome.Animals -Eighty-seven dogs with atopic dermatitis.Methods and materials -Dogs were fed an elimination diet and treated with either prednisolone or oclacitinib for two to three weeks. Relapsing dogs were treated a second time. In the absence of a relapse after two weeks off medication, dogs then were challenged. Dogs never achieving two weeks off treatment without relapse received the regular EDT.Results -Fifty-eight of 87 dogs completed the study. Thirty-nine of 58 dogs received prednisolone; 21 of these were diagnosed with FIAD and had no relapse (n = 14), one relapse (n = 6) or two relapses (n = 1). Nineteen of 58 dogs received oclacitinib; 11 of these were deemed food-allergic and had no relapse (n = 7) or two relapses (n = 4). The initial treatment duration did not influence the outcome. The threshold of one relapse or less for the diagnosis of FIAD was associated with a sensitivity of 95% for prednisolone and 63% for oclacitinib. The specificity was 100% for both drugs.Conclusion and clinical importance -Initial prednisolone or oclacitinib use in EDT shortens the time to diagnosis of FIAD.

A retrospective study of treatment, outcome, recurrence and concurrent diseases in 190 dogs with anal sacculitis

“…These dogs were diagnosed with allergic dermatitis by the primary author, either before developing AS or subsequently during the study period. The diagnoses were based on compatible clinical cutaneous signs, exclusion of other pruritic skin disease and performance of a dietary trial with provocation according to published criteria 28–30 . Thirty‐one (16.3%, 95% exact CI 11.4%–22.4%) had a diagnosis of cAD, whilst 19 (10.0%, 95% exact CI 6.1%–15.2%) had CAFR, and 68 (35.8%, 95% exact CI 29.0%–43.0%) had been diagnosed with a combination of both (Tables 2 and 6).…”

“…Younger dogs also were more commonly diagnosed with concurrent CAFR or cAD + CAFR. The higher number of visits recorded in the younger dogs until clinical resolution of AS were possibly a consequence of concurrent unmanaged allergic inflammation, which needed to be investigated following application of diagnostic criteria [28][29][30] whilst treating AS. We speculate that the undiagnosed cAD and/or CAFR, might contribute to and delay the resolution of AS.…”

“…The diagnoses were based on compatible clinical cutaneous signs, exclusion of other pruritic skin disease and performance of a dietary trial with provocation according to published criteria. [28][29][30] Thirty-one (16.3%, 95% exact CI 11.4%-22.4%) had a diagnosis of cAD, whilst 19 (10.0%, 95% exact CI 6.1%-15.2%) had CAFR, and 68 (35.8%, 95% exact CI 29.0%-43.0%) had been diagnosed with a combination of both (Tables 2 and 6). Dogs with AS and cutaneous allergic disease were overrepresented compared with the primary practice population in each category (cAD, CAFR and cAD + CAFR, each comparison p < 0.001).…”

An open‐label clinical trial to evaluate the efficacy of an elemental diet for the diagnosis of adverse food reactions in dogs

“…Several more recent studies have shown that CAFR can be successfully diagnosed in six weeks or less with appropriate antipruritic control and subsequent withdrawal of therapy. 14,21 In our study the ED allowed four of 18 CAFR dogs (22.22%) to complete their EDT at six weeks because their level of pruritus was considered acceptable at PVAS ≤ 3, they did not show signs of infection and antipruritic medications were discontinued before challenge. The benchmark PVAS ≤ 3 was extrapolated from the inclusion criteria from a previous study.…”