Use of prednisolone as monotherapy in the treatment of feline pemphigus foliaceus: a retrospective study of 37 cats

Abstract

Background Prednisone doses of up to 8 mg/kg/day have been used to treat feline pemphigus foliaceus (PF). Oral prednisolone has more favourable pharmacokinetics in cats than prednisone; therefore, lower doses of prednisolone may be effective in treating feline PF. Hypothesis/Objectives To assess the dose of prednisolone required to induce and maintain remission of PF in cats. Animals Thirty‐seven client‐owned cats with a diagnosis of PF treated with prednisolone monotherapy for induction of remission. Methods A retrospective analysis of records of a veterinary dermatology referral practice between the years of 1995 and 2013 was carried out. History, clinical signs, cytological and/or histopathological findings, lack of response to antimicrobials, absence of fungal hyphae on periodic acid Schiff staining and/or negative fungal culture and positive response to immunosuppressive therapy were used to confirm the diagnosis. Cats were included in the study if prednisolone was used as the monotherapy induction protocol. Results Complete remission was achieved within 8 weeks in 97% of cats with a median induction dose of 2 mg/kg prednisolone daily. In cats requiring ongoing treatment, 67% were maintained in remission with prednisolone monotherapy. The median maintenance dose was 1.2 mg/kg/week. In 14% of cats, medication was eventually discontinued. Conclusions and clinical importance Daily prednisolone at 2 mg/kg is an effective dose for inducing remission of PF in cats. Adverse effects were uncommon with this dose. In a small population, permanent remission may be induced. Secondary bacterial overgrowth and exudate in claw folds resolved in all cases with immunosuppressive therapy; therefore, antimicrobial therapy may be unnecessary.

Clinicopathological findings and clinical outcomes in 49 cases of feline pemphigus foliaceus examined in Northern California, USA (1987–2017)

“…The decision to prescribe multimodal therapy in a minority of cats at time of diagnosis may have been influenced by clinician preferences, perceived severity of disease, patient comorbidities or a combination thereof. The median induction doses for prednisolone when used as monotherapy and multimodal therapy were 2.8 mg/kg/day and 2.32 mg/kg/day respectively, consistent with previous reports . These results provide further support that lower doses of prednisolone can be effective at inducing complete remission in comparison to the historically recommended dose of 4‐5 mg/kg/day in feline patients with PF .…”

“…Due to the frequency of severe adverse effects, long‐acting injectable glucocorticoids are no longer recommended for long‐term management of feline PF . Some studies have advocated the use of various oral corticosteroids, either as monotherapy, or in combination with adjunctive ciclosporin or chlorambucil …”

“…Histopathological evaluation with exclusion of infectious aetiologies confirms PF in a variety of species, including humans, dogs, cats, horses, goats and sheep . To date, comparatively fewer studies have described the pathophysiology, clinical course and treatment outcomes of PF in cats relative to humans and dogs . Similarly, little has been published regarding the impact of PF and its management on the quality of life (QoL) of cats and their owners .…”

An unresponsive progressive pustular and crusting dermatitis with acantholysis in nine cats

“…The presence of acantholytic cells is most often associated with pemphigus foliaceus, although occasionally pyoderma or dermatophytes may disrupt normal keratinocyte cohesion producing acantholytic cells . Pemphigus foliaceus in cats is treated with immunosuppressive / immune‐modulating medications, such as glucocorticosteroids, chlorambucil, ciclosporin and gold salts …”

“…4 Pemphigus foliaceus in cats is treated with immunosuppressive / immune-modulating medications, such as glucocorticosteroids, chlorambucil, ciclosporin and gold salts. 2,5,6 This report describes nine cats, seen during a 14 year period, that presented with a progressive, markedly crusting dermatitis characterized histologically by variable numbers of intralesional acantholytic cells. The infectious agents isolated in six cats could not be identified as causative agents and no adverse drug reactions were identified.…”