Establishment of clinical criteria for the diagnosis of adverse food reactions in dogs with atopic dermatitis.

BACKGROUND: Diagnosis of canine adverse food reactions (AFRs) is based on vague criteria, such as '>50% improvement' during elimination diet trial (EDT) followed by 'deterioration' during provocation test (PT). OBJECTIVE: The objective of the study was to use predefined criteria to evaluate response during EDT [i.e., Owner Global Assessment of Treatment Efficacy (OGATE) = good-to-excellent] and relapse during PT [i.e., Owner Global Assessment of Challenge Deterioration (OGACD) = moderate-to-severe and/or >100% increase of lesional (Canine Atopic Dermatitis Extent and Severity Index, 4th iteration, CADESI-04) and/or of pruritus (pruritus Visual Analog Scale, PVAS) scores]. ANIMALS: Twenty-nine dogs with atopic dermatitis. MATERIALS AND METHODS: An extensively hydrolysed diet was fed to all dogs followed, in seven of 11 nonresponders, by a second home-made novel-protein EDT. Dogs responding to either EDT were challenged with their previous diet. RESULTS: Thirteen (44.8%) dogs were diagnosed with AFRs: at the end of EDT, their OGATE was good (9 of 13; 69.2%) or excellent (four of 13; 30.8%), and both CADESI-04 (46.7%) and PVAS (71.1%) had decreased significantly; at the end of PT, OGACD was moderate or severe in 12 of 13 (92.3%) dogs, and both CADESI-04 (127.9%) and PVAS (181.8%) had increased significantly. Of the 16 dogs without AFRs, 6 (37.5%) responded to the commercial (n = 5) or home-made (n = 1) diet [OGATE = good (three of six) or excellent (three of six)], with significant concurrent reduction of CADESI-04 and nonsignificant reduction of PVAS, yet they did not relapse during PT. CONCLUSIONS AND CLINICAL RELEVANCE: The proposed (predefined) criteria for the evaluation of response during EDT and deterioration during PT seem reliable and are easily applicable in clinical practice and research.

Investigation of the diagnostic performance of prick test with two environmental allergens in dogs with atopic dermatitis: A study using intradermal test as the gold standard.

BACKGROUND: There are no studies investigating the correlation between prick test (PT) and intradermal test (IDT) with environmental allergens in dogs with atopic dermatitis (AD). OBJECTIVES: To investigate the correlation between PT and IDT for two environmental allergens, and to calculate the sensitivity, specificity and Youden index of PT, using IDT as the gold standard. MATERIALS AND METHODS: Twenty-two dogs with AD were selected. PT was performed with glycerinated allergen extracts, along with negative and positive controls, using the Greer Prick System. Reactions were interpreted (positive/negative) subjectively and by using seven objective criteria, by an examiner blinded to the IDT results. IDT reactions to the same allergens were interpreted, subjectively and objectively, by another masked investigator. The agreement between PT and IDT, the sensitivity, specificity and Youden index of PT, using IDT as gold standard, were calculated. RESULTS: On subjective evaluation, the correlation between PT and IDT was poor and sensitivity of PT was 0%. Of the seven criteria for the objective evaluation of PT, the best diagnostic performance was attained when allergen-induced wheals were considered positive if their longest diameter was ≥8.5 mm. However, even then, the correlation with IDT was moderate, and the sensitivity of PT, albeit based on few positive IDT reactions, was low. CONCLUSION AND CLINICAL RELEVANCE: At least as performed herein, PT has a poor-to-moderate correlation with IDT, mainly as a consequence of the lack of positive PT reactions. Further studies are needed to improve PT technique, yet, meanwhile, it cannot be recommended as a substitute for IDT.

Repeatability and reproducibility of the interpretation of intradermal test results in dogs with atopic dermatitis.

Background - There is lack of studies evaluating the repeatability and reproducibility of the interpretation of intradermal testing in dogs with atopic dermatitis (AD). Objectives - To evaluate the repeatability and reproducibility of the interpretation of intradermal test results in dogs with AD. For comparison, the repeatability of allergen-specific immunoglobulin (Ig)E serology also was examined. Materials and methods - Twenty dogs with AD were used. Intradermal test included injections of known negative and positive controls, and of 25 masked injections of 10 allergens/controls, that were selected randomly and injected at random positions. Reactions to the 25 masked allergens/controls were scored (positive/negative) subjectively by three independent examiners followed by an objective assessment. Allergen-specific IgE serology was performed in blinded duplicate samples collected from all dogs for nine of 10 of the same allergens. Results - Kappa values of intraobserver repeatability (≥2 injections of the same allergen to different positions of the same dog) varied between -0.53 and 0.8 (subjective evaluations), and between 0.03 and 1 (objective evaluation). When the repeatability of the serological test was examined k = 0.91. Kappa values for the interobserver reproducibility (objective and three subjective evaluations of the same allergen injected at the same position of the same dog) varied between 0.6 and 0.74 (overall 0.67). Conclusions and clinical relevance - Intraobserver repeatability of the subjective and objective evaluation of IDT results varied from good to poor and depended on the number of times the same allergen was injected, whereas interobserver reproducibility varied from substantial to moderate. Further studies are needed to optimise the repeatability and reproducibility of IDT in dogs.

Contexte - Il existe un manque d'études évaluant la répétabilité et la reproductibilité de l'interprétation des tests intradermiques chez les chiens atteints de dermatite atopique (DA). Objectifs - Évaluer la répétabilité et la reproductibilité de l'interprétation des résultats des tests intradermiques chez les chiens atteints de MA. À des fins de comparaison, la répétabilité de la sérologie de l'immunoglobuline (Ig)E spécifique de l'allergène a également été examinée. Matériels et méthodes - Vingt chiens atteints de MA ont été utilisés. Le test intradermique comprenait des injections de contrôles négatifs et positifs connus, et de 25 injections masquées de 10 allergènes/contrôles, qui ont été sélectionnés au hasard et injectés à des positions aléatoires. Les réactions aux 25 allergènes/contrôles masqués ont été notées (positives/négatives) subjectivement par trois examinateurs indépendants, suivies d'une évaluation objective. La sérologie IgE spécifique de l'allergène a été réalisée dans des échantillons en double en aveugle prélevés sur tous les chiens pour neuf des 10 allergènes identiques. Résultats - Les valeurs kappa de répétabilité intra-observateur (≥2 injections du même allergène à différentes positions du même chien) variaient entre -0,53 et 0,8 (évaluations subjectives), et entre 0,03 et 1 (évaluation objective). Lorsque la répétabilité du test sérologique a été examinée, k = 0,91. Les valeurs de Kappa pour la reproductibilité interobservateur (évaluations objective et trois évaluations subjectives du même allergène injecté au même endroit du même chien) variaient entre 0,6 et 0,74 (globalement 0,67). Conclusions et pertinence clinique - La répétabilité intra-observateur de l'évaluation subjective et objective des résultats IDT variait de bonne à mauvaise et dépendait du nombre d'injections d'un même allergène, alors que la reproductibilité inter-observateur variait de substantielle à modérée. D'autres études sont nécessaires pour optimiser la répétabilité et la reproductibilité de l'IDT chez le chien.

Introducción- faltan estudios que evalúen la repetibilidad y la reproducibilidad de la interpretación de las pruebas intradérmicas en perros con dermatitis atópica (AD). Objetivos- evaluar la repetibilidad y reproducibilidad de la interpretación de los resultados de las pruebas intradérmicas en perros con AD. A modo de comparación, también se examinó la repetibilidad de la serología de inmunoglobulina (Ig)E específica de alérgeno. Materiales y métodos - Se utilizaron 20 perros con AD. La prueba intradérmica incluyó inyecciones de controles positivos y negativos conocidos, y de 25 inyecciones enmascaradas de 10 alérgenos/controles, que se seleccionaron al azar y se inyectaron en posiciones aleatorias. Las reacciones a los 25 alérgenos/controles enmascarados fueron calificadas (positivas/negativas) subjetivamente por tres examinadores independientes seguido de una evaluación objetiva. La serología de IgE específica para alérgenos se realizó en muestras duplicadas ciegas recolectadas de todos los perros para nueve de 10 de los mismos alérgenos. Resultados - Los valores Kappa de repetibilidad intraobservador (≥2 inyecciones del mismo alérgeno en diferentes posiciones del mismo perro) variaron entre -0,53 y 0,8 (evaluaciones subjetivas) y entre 0,03 y 1 (evaluación objetiva). Cuando se examinó la repetibilidad de la prueba serológica k = 0,91. Los valores de Kappa para la reproducibilidad interobservador (objetivo y tres evaluaciones subjetivas del mismo alérgeno inyectado en la misma posición del mismo perro) variaron entre 0,6 y 0,74 (en general, 0,67). Conclusiones y relevancia clínica- la repetibilidad intraobservador de la evaluación subjetiva y objetiva de los resultados de la IDT varió de buena a mala y dependió del número de veces que se inyectó el mismo alérgeno, mientras que la reproducibilidad interobservador varió de sustancial a moderada. Se necesitan más estudios para optimizar la repetibilidad y reproducibilidad de IDT en perros.

Contexto - Há poucos estudos avaliando a repetibilidade e reprodutibilidade da interpretação do teste intradérmico em cães com dermatite atópica (DA). Objetivos - Avaliar a repetibilidade e reprodutibilidade da interpretação dos resultados de testes intradérmicos em cães com DA. Para comparação, a repetibilidade da sorologia com imunoglobulinas (Ig)E alérgeno-específicas foi também avaliada. Materiais e métodos - Foram utilizados 20 cães com DA. O teste intradérmico incluiu injeções de controles negativos e positivos conhecidos e de 25 injeções mascaradas de 10 alérgenos/controles, que foram selecionados aleatoriamente e injetadas em posições aleatórias. As reações aos 25 alérgenos/controles mascarados foram pontuadas (positiva/negativa) subjetivamente por três examinadores independentes, seguidas de uma avaliação objetiva. A sorologia de IgE específica para alérgenos foi realizada em amostras duplicadas cegas coletadas de todos os cães para nove de 10 dos mesmos alérgenos. Resultados - Os valores Kappa de repetibilidade intraobservador (≥2 injeções do mesmo alérgeno em diferentes posições do mesmo cão) variaram entre -0,53 e 0,8 (avaliação subjetiva) e entre 0,03 e 1 (avaliação objetiva). Quando examinada a repetibilidade do teste sorológico k=0,91. Os valores de Kappa para a reprodutibilidade interobservador (objetiva e três avaliações subjetivas do mesmo alérgeno injetado na mesma posição do mesmo cão) variaram entre 0,6 e 0,74 (total 0,67). Conclusões e relevância clínica - A repetibilidade intraobservador da avaliação subjetiva e objetiva dos resultados do IDT variou de boa a ruim e dependeu do número de vezes que o mesmo alérgeno foi injetado, enquanto a reprodutibilidade interobservador variou de substancial a moderada. Mais estudos são necessários para otimizar a repetibilidade e reprodutibilidade do IDT em cães.

Efficacy of Antimicrobial Treatment in Dogs with Atopic Dermatitis: An Observational Study.

There is a shortage of studies reporting the efficacy of antimicrobial treatment of dogs with atopic dermatitis (AD) and skin infections (SIs). The aim of this study was to evaluate the change in the severity of skin lesions and pruritus, and the overall efficacy of antimicrobial treatment, in dogs with AD and bacterial overgrowth/infection and/or Malassezia dermatitis. A total of 20 dogs with AD and SIs were prospectively enrolled (group A) and they were examined before and after the administration of systemic antimicrobials that resulted in the resolution of SIs. In addition, 19 dogs fulfilling the same inclusion criteria and treated with systemic, with or without topical antimicrobials, were included retrospectively (group B). Since there were no major differences between the groups, their results were combined. The severity of skin lesions decreased significantly, by 30% based on Canine Atopic Dermatitis Extent and Severity Index-4 (CADESI-4), by 28.1% based on the erythema domain of CADESI-4 and based on owner's global assessment of the severity of skin lesions. Pruritus decreased significantly, by 34.7% based on the Pruritus Visual Analogue Scale (PVAS). The efficacy of antimicrobial treatment was assessed as good to excellent by the investigator and the owner in 55% and 60% of the dogs, respectively. Despite the significant improvement, there was high variability in the response to treatment among dogs. Further studies are needed to find factors that determine the response to antimicrobial treatment in dogs with AD and SIs.