A pilot trial on the effect of Cyclosporin A on intradermal skin test reactions in dogs with atopic dermatitis

Abstract

The purpose of this study was to determine if Cyclosporin A, given at a dose of 5 mg kg−1 per day for 42 days, negatively influenced intradermal skin test results in dogs with atopic dermatitis. Six mixed‐breed dogs of varying ages and sexes with a clinical diagnosis of atopic dermatitis were included in this study. All dogs were intradermally skin tested (IDT) with 61 allergens from varying groups, grass pollens, weed pollens, tree pollens, moulds, insects and dust mites. IDT reactions were recorded as absent, weak, moderate or strong reactions. All dogs showed several strong reactions in the initial IDT. On days 0 to 42, the dogs received 5 mg kg −1 per day of Cyclosporin A. On day 42, all dogs showed a marked reduction in pruritus. A second IDT was performed and the results of both tests compared. The χ2‐test was used to statistically analyse changes between pre‐ and post‐treatment reactions for each of the allergen groups. There were no mould reactions recorded and this group was discarded from analysis. When all reactions were used in analysis, Cyclosporin A tended to significantly reduce the number of IDT reactions. However, when only moderate and strong reactions were considered (weak reactions excluded) there were no significant differences between pre‐ and post‐treatment results for the other allergen groups. Cyclosporin A at a dose of 5 mg kg−1 per day for 42 days controlled pruritus, but did not significantly alter moderate and strong intradermal skin test reactions in the six dogs tested. This suggests that Cyclosporin A, at this dose, did not prevent mast cell degranulation. Funded by Novartis Animal Health, Australia.

Evidence‐based guidelines for anti‐allergic drug withdrawal times before allergen‐specific intradermal and IgE serological tests in dogs

“…There were no statistically significant differences in positive (i.e. moderate to strong) reactions to environmental allergens before and after treatment …”

“…In another trial, 16 dogs with AD were randomly given either placebo or ciclosporin (Atopica; Novartis Animal Health, Basel, Switzerland) for 30 days at 5 mg/kg once daily . Similar to the results of the other trials, ciclosporin did not significantly inhibit IDT immediate reactivity to the tested allergens compared with placebo …”

“…In one study, ciclosporin (Atopica; Novartis Animal Health, Basel, Switzerland) was administered at 5 mg/kg p.o. once daily for 6 weeks to six dogs with AD.…”

Investigation on the effects of topical therapy with 0.1% tacrolimus ointment (Protopic®) on intradermal skin test reactivity in atopic dogs

“…Tacrolimus and cyclosporin share numerous mechanisms of action, 42 and lack of suppression of immediate IST reaction has also been reported with cyclosporin treatment in dogs 41 . Unpublished pilot information on the effect of cyclosporin on immediate IST reactions suggested that cyclosporin at 5 mg kg −1 did not suppress reactivity 43 . Unfortunately late‐phase reactions were not evaluated in that study 43 …”

Dermal microdialysis in the dog: in vivo assessment of the effect of cyclosporin A on cutaneous histamine and prostaglandin D2 release

“…In parallel to the cutaneous histamine inhibition, a significant decrease on the skin wheal area was observed during CsA treatment. There are few studies in dogs reporting the effect of oral CsA on intradermal tests, although a study in atopic dogs showed a weak reduction on wheal size after 45 days of CsA oral treatment 17 . Studies in humans have shown that histamine is the major mast cell mediator responsible for the development of the wheal, there being a strong correlation between the concentration of histamine recovered by microdialysis and the wheal area 18 .…”