A randomized controlled trial of misoprostol monotherapy for canine atopic dermatitis: effects on dermal cellularity and cutaneous tumour necrosis factor-alpha

Abstract In this blinded randomized placebo-controlled trial, 20 dogs with atopic dermatitis (AD) were given placebo (8 dogs) or misoprostol (12 dogs) at 5 µg kg⁻¹, orally, three times daily for 3 weeks. Administration of the active drug, but not of placebo, led to a significant decrease in lesional and pruritus scores. The median reduction from baseline of both scores was ≈30%. Misoprostol therapy did not lead to decreases of dermal cell counts or skin tumour necrosis factor (TNF)α mRNA copy numbers that were significantly different from those of placebo. Skin TNFα protein production, assessed using indirect immunofluorescence, decreased or remained unchanged in dogs receiving misoprostol. In contrast, post treatment TNFα fluorescence scores were higher in all but two dogs given placebo. The changes from baseline of TNFα fluorescence scores did not correlate significantly with those of lesional or pruritus indices. These observations confirm the modest efficacy of misoprostol for treatment of canine AD and suggest that its mild anti-allergic effects are not associated with either inhibition of inflammatory cell emigration or TNFα production.