Hilary A. Jackson

Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic relapsing pruritic skin disease of dogs for which treatment has varied over time and geographical location. Recent high quality randomized controlled trials and systematic reviews have established which drugs are likely to offer consistent benefit. The International Task Force for Canine AD currently recommends a multi-faceted approach to treat dogs with AD. Acute flares should be treated with a combination of nonirritating baths and topical glucocorticoids, once an attempt has been made to identify and remove the suspected causes of the flare. Oral glucocorticoids and antimicrobial therapy must be added when needed. In dogs with chronic AD, a combination of interventions should be considered. Again, factors that trigger flares of AD must be identified and, if possible, avoided. Currently recognized flare factors include food, flea and environmental allergens, Staphylococcus bacteria and Malassezia yeast. Skin and coat hygiene and care must be improved by bathing with nonirritating shampoos and dietary supplementation with essential fatty acids. The severity of pruritus and skin lesions can be reduced with a combination of anti-inflammatory drugs. Currently, medications with good evidence of high efficacy include topical and oral glucocorticoids, and calcineurin inhibitors such as oral ciclosporin and topical tacrolimus. The dose and frequency of administration of these drugs should be tailored to each patient considering each drugs efficacy, adverse effects and cost. Allergen-specific immunotherapy should be offered, whenever feasible, in an attempt to prevent recurrence of clinical signs upon further exposure to environmental allergens to which the patient is hypersensitive.

Epicutaneous sensitization with Dermatophagoides farinae induces generalized allergic dermatitis and elevated mite-specific immunoglobulin E levels in a canine model of atopic dermatitis

Background Atopic dermatitis (AD) is a cutaneous hypersensitivity associated with elevated levels of antigen‐specific IgE, commonly to house dust mites (HDMs). It remains controversial as to whether sensitization and clinical disease are induced by cutaneous exposure to HDM.

Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA)

BackgroundIn 2010, the International Task Force on Canine Atopic Dermatitis (now International Committee on Allergic Diseases of Animals, ICADA) published the first consensus guidelines for the treatment of atopic dermatitis (AD) in dogs. This is the first 5-year minor update of this document.ResultsThe treatment of acute flares of AD should involve the search for, and then elimination of, the cause of the flares, bathing with mild shampoos, and controlling pruritus and skin lesions with interventions that include topical and/or oral glucocorticoids or oclacitinib. For chronic canine AD, the first steps in management are the identification and avoidance of flare factors, as well as ensuring that there is adequate skin and coat hygiene and care; this might include more frequent bathing and possibly increasing essential fatty acid intake. The medications currently most effective in reducing chronic pruritus and skin lesions are topical and oral glucocorticoids, oral ciclosporin, oral oclacitinib, and, where available, injectable recombinant interferons. Allergen-specific immunotherapy and proactive intermittent topical glucocorticoid applications are the only interventions likely to prevent or delay the recurrence of flares of AD.ConclusionsThis first 5-year minor update of the international consensus guidelines for treatment of AD in dogs further establishes that the treatment of this disease is multifaceted, and that interventions should be combined for a proven (or likely) optimal benefit. Importantly, treatment plans are likely to vary between dogs and, for the same dog, between times when the disease is at different stages.

A comparison of the clinical manifestations of feeding whole and hydrolysed chicken to dogs with hypersensitivity to the native protein

Twenty-six dogs with known adverse food reactions were fed whole chicken for 14 days. From this group, 12 dogs with cutaneous manifestations following exposure to chicken meat were selected and randomly divided into two groups (n = 6). Each group was then fed hydrolysed chicken or hydrolysed soy for 14 days in a blinded crossover design with a 17-day washout period between each diet. Assessments of a CADESI (Canine Atopic Dermatitis Extent and Severity Index) score and pruritus were performed throughout the entire study, and combined in a global score (GS). Serum was collected weekly for the measurement of chicken- and soy-specific IgG and IgE. Dogs displayed the most severe clinical response when eating whole chicken compared to baseline (P < 0.001). The GS was significantly reduced in 11 of the 12 dogs when fed hydrolysed chicken were compared to those fed whole chicken (3.58 ± 2.81 versus 20.38 ± 14.65, P < 0.01). Serum immunoglobulin G and E responses were variable and did not show relationship with specific dietary exposure.

A pilot open trial evaluating the efficacy of low-dose aminopterin in the canine homologue of human atopic dermatitis.

SIR, Methotrexate and aminopterin (AMT) are antifolate agents that also exhibit anti-inflammatory effects stemming from several mechanisms that include the extracellular release of adenosine, a potent anti-inflammatory autocoid. Because of such properties, methotrexate has been used in the last decade for treatment of inflammatory conditions such as psoriasis. Results from two open trials suggested that methotrexate benefited human patients with atopic dermatitis (AD). Compared with methotrexate, AMT appears to be more potent and to have a higher bioavailability and lower toxic effects. In this proof-of-concept open two-phase trial, we report the efficacy of AMT in the spontaneous canine model of human AD. In the first phase that lasted 4 weeks, nine dogs with perennial AD diagnosed with conventional methods were given oral AMT 0Æ010 mg kg once weekly. During this phase, subjects did not receive any other interventions outside of weekly antimicrobial shampoos and monthly flea preventatives. Before, and 2 and 4 weeks after beginning AMT, investigators graded skin lesions using the validated Canine Atopic Dermatitis Extent and Severity Index (CADESI). Additionally, owners rated the degree of pruritic manifestations using a 10-point visual analogue scale (PVAS). A global score (GS) combined previous grades as follows: GS = (CADESI · PVAS) ⁄100. At the end of this phase, investigators and owners evaluated subjectively the overall efficacy of AMT using a scale from 0 (no efficacy; < 10% reduction in signs) to 4 (very good efficacy; 75–90% reduction in signs). During the second phase, which could last up to 11 months, dogs received AMT 0Æ010 mg kg once weekly, but this dosage could be increased to 0Æ015 and 0Æ020 mg kg once weekly in case of need. In this extension phase, anti-infectious and ⁄or anti-inflammatory medications were allowed if necessary, and were recorded. Patients were seen monthly and evaluated as above. Weekly during the first month, and every 2–4 weeks thereafter, blood was drawn for full blood counts and serum chemistry panels. Eight of nine dogs completed the 4-week induction phase; one dog (no. 7) was withdrawn because of bacterial folliculitis. CADESI and GS values, but not PVAS numbers, were significantly lower after 4 weeks compared with pretreatment (repeated-measures ANOVA, P < 0Æ05; Fig. 1). After 4 weeks, the median reductions in CADESI, PVAS and GS were 36%, 2Æ8 ⁄10 points and 62%, respectively. At that time, a ‡ 50% reduction from baseline CADESI and GS values was achieved in three of eight and six of eight dogs, respectively (Table 1), and the overall efficacy rating was 2Æ2, a value slightly above the ‘fair efficacy; 25–50% reduction’ mark. Seven dogs continued to receive AMT for up to 40 weeks. One dog (no. 5) was withdrawn after 8 weeks because of lack of efficacy despite doubling the dosage of AMT. Altogether, six of seven dogs (86%) achieved a ‡ 80% reduction in baseline GS values at one time point during the extension phase (Tables 1 and 2), and the disease neared or was in complete Fig 1. Evolution of global scores over 4 weeks in nine dogs treated with aminopterin. In the upper panel, each line corresponds to a different patient. In the lower panel, boxes correspond to the 95% confidence interval, the line is the median and the whiskers highlight the range of values. CADESI, Canine Atopic Dermatitis Extent and Severity Index; PVAS, pruritus visual analogue scale.

Comparing immediate-type food allergy in humans and companion animals—revealing unmet needs

Adverse food reactions occur in human as well as veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in both. In this position paper, we summarize the current knowledge on immediate‐type food allergy vs other food adverse reactions in companion animals, and compare this to the human situation. While the prevalence of food allergy in humans has been well studied for some allergens, this remains to be investigated for animal patients, where owner‐reported as well as veterinarian‐diagnosed food adverse reactions are on the increase. The characteristics of the disease in humans vs dogs, cats, and horses are most often caused by similar, but sometimes species‐dependent different pathophysiological mechanisms, prompting the specific clinical symptoms, diagnoses, and treatments. Furthermore, little is known about the allergen molecules causative for type I food allergy in animals, which, like in human patients, could represent predictive biomarkers for risk evaluation. The definite diagnosis of food allergy relies—as in humans—on elimination diet and provocation tests. Besides allergen avoidance in daily practice, novel treatment options and tolerization strategies are underway. Taken together, numerous knowledge gaps were identified in veterinary food allergy, which need to be filled by systematic comparative studies.