Topical 0.1% tacrolimus for the treatment of discoid lupus erythematosus and pemphigus erythematosus in dogs

Abstract

Skin lesions of discoid lupus erythematosus (DLE) and pemphigus erythematosus (PE) are often localized to the nasal planum, dorsal muzzle and less commonly, pinnae, periocular skin and lips. The objective of this study was to explore the use of 0.1% tacrolimus as a topical therapy in the management of localized DLE and PE lesions in dogs. Ten cases of DLE and two cases of PE in various breeds were included. Degree of erythema, crust, ulceration or erosion, depigmentation and scarring were evaluated at the start of the trial and after 2, 4 and 8 weeks of therapy. Complete blood count, serum chemistry and whole blood tacrolimus concentrations (Abbot IMx Microparticle Immunoassay; Abbot IMx, Chicago, IL, USA) were performed at each evaluation. Ten cases of DLE and two cases of PE were treated using the lotion either as a sole therapy (both DLE) or as an adjunctive treatment (eight DLE and two PE). Five of the cases evaluated had an excellent response (three DLE and two PE), five a partial response (all DLE), and two dogs (both DLE) showed no appreciable difference after receiving topical tacrolimus therapy. Concurrent medications were discontinued in eight of the ten dogs that improved. No adverse effects in clinical or laboratory parameters were noted throughout the study. However, measurement of tacrolimus concentrations by the MEIA assay was of little benefit due to false‐positive measurements. Results of this study indicate that topical 0.1% tacrolimus may be a safe and effective adjunctive therapy for DLE and PE, with fewer systemic and topical adverse effects than current treatment modalities.