Rapid response of hyperkeratotic erythema multiforme to oclacitinib in two dogs

Oclacitinib therapy in two cats with refractory proliferative and necrotising otitis externa

Feline proliferative and necrotising otitis externa (PNOE) is a rare immune-mediated condition, usually self-limiting or responsive to immunosuppressants such as topical tacrolimus. This case report describes two cats with refractory PNOE that responded successfully to oclacitinib. One cat also had middle ear involvement and the other cat had extra-auricular dermatitis.

Successful treatment of sebaceous adenitis with oclacitinib and low-dose prednisolone in a dog

Finding an effective and well-tolerated treatment for canine idiopathic sebaceous adenitis (ISA) can be challenging. This case report describes an 8-year-old male Rottweiler with ISA successfully treated with a combination of oclacitinib and low doses of prednisolone.

Novel Management of Masticatory Myositis in Three Dogs with a Selective Janus Kinase (JAK-1) Inhibitor

Masticatory myositis (MM) is an inflammatory myopathy reported in dogs and is characterized by inflammation of the masticatory muscles (temporalis, masseter, and pterygoid muscles). Immunosuppressive therapy is the current recommended treatment for MM and may involve glucocorticoids, cyclosporine, azathioprine, mycophenolate mofetil, leflunomide, or a combination of these treatments that are slowly tapered to the lowest effective dose. However, side effects from multimodal medical therapy and complications associated with MM relapses have been reported. The purpose of this case series was to report oclacitinib as a treatment alternative to traditional medical management of MM. The intent of this alternative is to manage side effects from glucocorticoid use. Oclacitinib (1mg/kg per os q12h) was used solely for treatment of MM in three dogs. The dogs were followed up to >6 months after oclacitinib administration. An increase in oral range of motion, as determined by gape angle, was noted in all three dogs. However, a corresponding drop in antibody titers (2M fiber) did not occur. All dogs showed improvement in overall clinical management of MM, side effects from glucocorticoids, and clinical signs related to chronic prednisone use. Larger controlled trials with consistent measurements (interincisal distance, gape angle) and 2M fiber antibody titers are indicated to further assess validation of oclacitinib treatment of MM. The clinical outcome of all dogs was considered successful.

The use of oclacitinib compared to azathioprine in the management of canine pemphigus foliaceus: A retrospective analysis

BACKGROUND

Oclacitinib (Apoquel; Zoetis) has been reported to be beneficial for treating immune-mediated disorders.

HYPOTHESIS/OBJECTIVES

This retrospective study evaluates in which group of dogs [oclacitinib (OC) or azathioprine (AZ)] remission of pemphigus foliaceus (PF) was more effectively achieved with matched induction dosing of glucocorticoids; it further evaluates which group had a higher glucocorticoid-sparing effect.

ANIMALS

Review of 30 medical records of dogs diagnosed with PF presented to a private practice dermatological service.

MATERIALS AND METHODS

Retrospective analysis of dogs diagnosed with PF and treated with OC or AZ in combination with glucocorticoids.

RESULTS

There was no significant difference in the ability to induce remission between AZ and OC groups. In the AZ group, 13 of 15 dogs went into some type of remission (partial or complete), compared with 11 of 15 in the OC group. There was no significant difference between the two groups for the glucocorticoid-sparing effect. The AZ group had an average reduction of 77.9% from the induction glucocorticoid dose, and OC group had an average reduction of 64.4%. One of 15 patients in the AZ group and three of 15 patients in the OC group had a 100% reduction of the glucocorticoid dose.

CONCLUSIONS AND CLINICAL RELEVANCE

These results indicate that OC can be considered as a treatment option for canine PF.

Successful treatment of perianal fistulas in two dogs with oclacitinib

Perianal fistula (PAF) formation in dogs is a frustrating and painful disease, occurring primarily in German shepherd dogs. Ciclosporin has become the recommended treatment of choice yet may be associated with numerous adverse effects. This case report describes the successful treatment of two cases of PAF with oclacitinib.

Hyperkeratotic erythema multiforme variant in 17 dogs

BACKGROUND

A new canine subgroup defined as 'old-dog' or 'hyperkeratotic' erythema multiforme (HKEM) with marked hyperkeratosis and parakeratosis has been proposed without any detailed description of larger case series.

OBJECTIVES

We report herein the signalment, clinical signs, treatment outcome, and histopathological and immunological findings in 17 dogs with HKEM.

ANIMALS

Inclusion criteria were the presence of (i) scaly skin lesions with or without crusting; and (ii) microscopic lesions typical of EM (i.e. a panepidermal cytotoxic lymphocytic dermatitis with or without basal keratinocyte apoptosis); and (iii) microscopic ortho- and/or parakeratotic hyperkeratosis affecting the interfollicular epidermis.

MATERIALS AND METHODS

Clinical questionnaires and skin biopsies were reviewed. Polymerase chain reactions for epidermotropic viruses and direct immunofluorescence were performed.

RESULTS

Various breeds were affected with an over-representation of males in their mid-to-late adulthood (median age 9 years). Generalised skin lesions included multifocal-to-coalescing, linear and annular macules and plaques with erythema and adherent firm crusting. Microscopic lesions were specific for EM and featured prominent superficial epidermal apoptosis with lymphocytic satellitosis and parakeratosis. No drug triggers were identified. Polymerase chain reactions for canine herpesvirus polymerase gene, canine parvovirus and canine distemper virus were negative in all HKEM and canine erosive EM (15 dogs) biopsies. Lesions failed to respond to oral and/or topical antimicrobials. Complete remission of signs was achieved in 9 of 17 dogs (53%) using immunosuppressive regimens.

CONCLUSIONS AND CLINICAL RELEVANCE

Hyperkeratotic erythema multiforme (HKEM) is a chronic, persistent and clinically distinctive erythema multiforme (EM) variant that differs from 'classic' vesiculobullous erosive-to-ulcerative EM in dogs.

Efficacy of oclacitinib for the control of feline atopic skin syndrome: correlating plasma concentrations with clinical response

OBJECTIVES

The aim of this study was to assess the efficacy of a new therapeutic regimen of oclacitinib for the control of feline atopic skin syndrome (FASS) and to correlate plasma levels of this drug with clinical effects.

METHODS

Twenty-eight client-owned cats with a clinical diagnosis of FASS were recruited. Oclacitinib was administered at 1 mg/kg q12h for 2 weeks and then at 1 mg/kg q24h for a further 2 weeks. At the study outset (D0), and 7 (D7) and 28 (D28) days after starting treatment, clinical lesions were assessed using a validated scoring system (SCORing Feline Allergic Dermatitis [SCORFAD]) and pruritus was graded via an adapted visual analogue scale (PVAS). At the same time points, plasma oclacitinib levels and haematological variables were measured.

RESULTS

Among 18 cats completing the study, PVAS and SCORFAD improved by ⩾50% in 61% and 88% of animals, respectively. Mean PVAS decreased significantly between D0 and D7 and between D0 and D28 (both P <0.001) but not between D7 and D28. Likewise, mean SCORFAD values decreased significantly between D0 and D7 and between D0 and D28 (both P <0.001) but not between D7 and D28. On D7 and D28, plasma oclacitinib concentrations varied widely from 0 to 1443.2 ng/ml and from from 0 to 1177.7 ng/ml, respectively. Oclacitinib concentrations showed no correlation with clinical effects (SCORFAD and PVAS).

CONCLUSIONS AND RELEVANCE

Oclacitinib emerged as being safe and effective to control clinical signs of FASS. A mean dose of 1 mg/kg, even without extending twice-daily treatment beyond the first 2 weeks, could be a suitable therapeutic regimen. Plasma drug levels did not seem useful to predict clinical response during treatment.

Prolonged twice-daily administration of oclacitinib for the control of canine atopic dermatitis: a retrospective study of 53 client-owned atopic dogs

BACKGROUND

Oclacitinib administered at the licensed dose twice daily for two weeks and then once daily as required is recommended for the treatment of atopic dogs. In some cases, the once-daily regimen is insufficient to control the clinical signs.

OBJECTIVES

To provide preliminary safety and efficacy data on the prolonged twice-daily administration of oclacitinib in atopic dogs.

ANIMALS

Fifty-three client-owned atopic dogs.

METHODS AND MATERIALS

The medical records of dogs with atopic dermatitis treated with oclacitinib twice daily for more than two weeks were reviewed retrospectively. Animal details, treatment dose and duration, concurrent diseases, adjunctive medications and possible adverse events were recorded. Treatment efficacy was assessed retrospectively and, when available, the selected blood parameters before and during the treatment were compared. Statistical analyses of the collected data were performed.

RESULTS

The median treatment duration was 113 days. Excellent-to-good efficacy was observed in 38 dogs (72%), including 24 of 33 dogs that failed to respond to the once-daily regimen. Eight dogs showed a poor response despite the addition of systemic glucocorticoids. Pyoderma, gastrointestinal signs and otitis externa were the most frequent adverse events recorded whilst on treatment. Blood tests performed in 35 dogs showed slightly decreased leucocyte, neutrophil, eosinophil and monocyte counts that remained within the reference ranges in most cases. Three dogs developed hypercholesterolemia.

CONCLUSIONS AND CLINICAL RELEVANCE

Prolonged twice-daily administration of oclacitinib generally was well-tolerated and was effective in most of the treated dogs. Regular clinical evaluation and blood tests are advisable for this treatment regimen.

Ear tip ulcerative dermatitis treated with oclacitinib in 25 dogs: a retrospective case series

BACKGROUND

Ear tip ulcerative dermatitis (ETUD) is an uncommon clinical reaction pattern in canine dermatology. The lesions are suggestive of vascular damage which may be caused by inflammatory or noninflammatory diseases, and often are idiopathic. Therapeutic options for ETUD include topical glucocorticoids or tacrolimus, pentoxifylline, vitamin E, doxycycline, tetracycline and niacinamide, sulfonamides, glucocorticoids, ciclosporin and surgical correction.

HYPOTHESIS/OBJECTIVES

The aims of this retrospective case series were to describe the clinical features and report response to treatment with oclacitinib in dogs with idiopathic, chronic ETUD.

ANIMALS

Twenty-five privately owned dogs with unilateral or bilateral ETUD.

METHODS AND MATERIALS

Cases of ETUD which were poorly responsive to conventional therapy and subsequently treated with oclacitinib, are summarised. All cases were tested for leishmaniosis by serological examination [indirect fluorescent antibody test (IFAT) or enzyme-linked immunosorbent assay (ELISA)]. Histopathological examination was performed in two cases.

RESULTS

Serological results were negative for leishmaniosis in all dogs. Histopathological changes consistent with proliferative thrombovascular necrosis of the pinnae were documented in two cases. Oclacitinib, used at the standard dose range recommended for the treatment of canine atopic dermatitis, effectively resolved ETUD in 22 of 25 dogs within one to three months. Several of the dogs required prolonged use of twice daily dosing.

CONCLUSIONS AND CLINICAL RELEVANCE

Oclacitinib should be included among the therapeutic options for ETUD, once infectious diseases have been ruled out.

Extra-auricular lesions of proliferative and necrotizing otitis externa in three kittens

BACKGROUND

Proliferative and necrotising otitis externa (PNOE) is a rare disorder in cats with poorly understood pathogenesis. Extra-auricular (EA) lesions recently have been mentioned in a textbook and in one case report.

OBJECTIVES

To describe EA lesions associated with PNOE in three kittens.

ANIMALS

A 6-month-old female domestic short hair (DSH) cat (Case 1), an 8-month-old female DSH cat (Case 2) and a 5-month-old female DSH cat (Case 3).

METHODS AND RESULTS

All cases exhibited classical lesions of PNOE associated with EA lesions, generalised (cases 1 and 3) or limited to eyelids (Case 2). Lesions were characterised by thick, adherent, hyperkeratotic papules coalescing to plaques and attempts to remove the hyperkeratotic plaques resulted in erosions. Histopathological examinations revealed classical features of PNOE: severe acanthosis associated with a marked lymphocytic exocytosis, satellitosis and apoptotic keratinocytes at all levels of the epidermis and the outer root sheath of hair follicles. Cases 2 and 3 resolved spontaneously. Case 1 remained stable with topical tacrolimus and oral prednisolone after a short course of ciclosporin.

CONCLUSIONS AND CLINICAL IMPORTANCE

This report describes EA lesions of PNOE in three kittens. Such lesions may be underdiagnosed, and this report emphasises the role of a thorough clinical inspection in PNOE cases.

Beneficial effect of oclacitinib in a case of feline pemphigus foliaceus

Pemphigus foliaceous (PF) is a pustular, immune-mediated skin disease characterised by acantholytic cells and commonly treated with high doses of glucocorticoids. This report describes one case of feline PF successfully controlled using oral oclacitinib, suggesting a possible therapeutic alternative to glucocorticoids in some cases.

Shared inflammatory and skin-specific gene signatures reveal common drivers of discoid lupus erythematosus in canines, humans and mice

Autoimmune skin diseases are complex and are thought to arise from a combination of genetics and environmental exposures, which trigger an ongoing immune response against self-antigens. Companion animals including cats and dogs are known to develop inflammatory skin conditions similar to humans and share the same environment, providing opportunities to study spontaneous disease that encompasses genetic and environmental factors with a One Health approach. A strength of comparative immunology approaches is that immune profiles may be assessed across different species to better identify shared or conserved pathways that might drive inflammation. Here, we performed a comparative study of skin from canine discoid lupus erythematosus (DLE) using NanoString nCounter technology. We compared these gene expression patterns to those of human DLE and a mouse model of cutaneous lupus. We found strong interferon signatures, with CXCL10, ISG15, and an S100 gene family member among the highest, most significant DEGs upregulated across species. Cell type analysis revealed marked T-cell and B-cell infiltration. Interestingly, canine DLE samples also recapitulated downregulated skin homeostatic genes observed in human DLE. We conclude that spontaneous DLE in dogs captures many features that are present in human disease and may serve as a more complete model for conducting further genomic and/or transcriptomic studies.

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Canine DLE lesions express known drivers of pathogenesis including CXCL10, IFNG, FAS.

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Enrichment of key cell types, including T, B, NK cells, is observed in canine DLE.

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Canine, mouse and human DLE share similar proinflammatory profiles.

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Canine DLE exhibits downregulated skin homeostatic and immune regulatory genes.