Further validation of a pruritus severity scale for use in dogs

Abstract

A scale to assess the severity of pruritus in dogs was further validated. Comparison of the scale with one containing visible numerical markings demonstrated that owners were heavily influenced by the presence of numbers, resulting in a loss of the scale's ability to generate continuous data. The presence of a traditional visual analogue scale was therefore essential. The scale was tested on 713 owners who presented their dogs for veterinary attention. Pruritus scores in 408 dogs with skin disease covered the full range of possible values (0 to 10). In 305 dogs with no skin disease, 90 owners gave a score greater than zero. Comparison of the scores seen in pruritic dogs, and dogs with no evidence of skin disease, allowed a 'normal range' of 0-1.9 to be established. The scale was able to discriminate between conditions typically regarded as pruritic or non-pruritic. When the scale was assessed for its ability to detect changes in pruritus score following treatment, a median reduction of 4.4 points was observed. The scale was also used to determine what magnitude of response owners would expect following treatment of their pruritic dogs. Only 12% would have been satisfied with a 50% reduction, a figure that is typically quoted as a satisfactory response in clinical trials of anti-pruritic drugs. As a result, alternative methods of assessing clinical trials are proposed. This study has shown the scale to be a valuable tool for clinical assessment of patients, and for monitoring treatment responses in clinical trials.

The prevalence of dogs with lymphocyte proliferative responses to food allergens in canine allergic dermatitis

“…Changes in clinical condition were carefully observed and noted by the owners. Pruritus was assessed by the owners using a vertical visual analog scale with grade descriptors (Rybnicek et al 2009) at the first visit and at least 2 weeks after elimination of the diet trial.…”

Eficácia da ciclosporina no controle da dermatite atópica em cães

“…Durante o tratamento dos cães com ciclosporina foi observada uma tendência de redução do escore de prurido, segundo os critérios de Rybnicek (2009), principalmente a partir do 14º dia e ao longo dos 63 dias de estudo, com uma redução significante (p<0,01) nos dias +14, +21, +28, +35, +42, +49 e +63, e no dia +56 (p<0,05) no momento da avaliação (Fig.2). A involução do prurido foi associada com a melhora sintomato-lesional dos pacientes, registrada pelo índice de CADESI (Olivry et al 2007).…”

“…Os valores das medianas no escore de prurido pelos critérios de Rybnicek (2009) dos cães tratados com prednisona foi reduzida a partir do início do tratamento e durante os 63 dias de estudo. Uma diferença significativa do escore do prurido foi observada nos dias +28, +35, +42, +49, +56 e +63 (p<0,001), e no dia + 21 (p<0,01) em relação ao momento inicial do tratamento (Fig.4).…”

“…Quando se comparou o escore de prurido segundo os critérios de Rybnicek (2009) nos dois grupos experimentais (Fig.6), foram observadas melhores índices de controle da intensidade do prurido no grupo tratado com prednisona, em relação ao grupo com ciclosporina a partir do 42º dia de avaliação (p<0,05), mantendo-se esta diferença nos dias +49, +56 e +63.…”

“…O escore de prurido foi avaliado semanalmente pelo pesquisador, obedecendo aos critérios de Rybnicek (2009), entre os dias 0 e 63 do estudo.…”