Oclacitinib in feline nonflea-, nonfood-induced hypersensitivity dermatitis: results of a small prospective pilot study of client-owned cats

Performance of applications of Ophytrium-containing mousse with or without shampoo in cats with pruritic and irritated skin: a multicentre prospective field trial

OBJECTIVES

This study aimed to evaluate the performance of a protocol in which topical products (DOUXO S3 CALM Shampoo and Mousse; Ceva Santé Animale) containing Ophytrium were applied to cats to help manage feline atopic syndrome (FAS).

METHODS

A total of 23 client-owned cats with a history of FAS and presenting irritated skin and pruritus were recruited for this study. The cats were either shampooed or moussed on day 0 (D0) and then moussed every 48-72 h for 3 weeks. On D0, D7 and D21, clinical signs were assessed using the validated scoring system, Scoring Feline Allergic Dermatitis (SCORFAD). Pruritus was graded by the owner using an adapted dual visual analogue scale (Pruritus Visual Analog Scale for Cats [VAScat]). Veterinarians also assessed pruritus intensity and frequency, and provided a subjective assessment of global skin condition and of improvements in each cat's condition. On D21, all questionnaires were collected from both veterinarians and owners.

RESULTS

Among the 19 cats that completed the study, the SCORFAD and VASmax (maximum value of VAScat, either scratching or licking) scores improved by ⩾50% in 63.2% and 38.9% of animals, respectively. Mean SCORFAD values decreased significantly between D0 and D21 (from 6.2 to 2.8, P <0.05). Similarly, mean VASmax values decreased significantly between D0 and D21 (from 7.4 to 4.3, P <0.05). Overall, veterinarians assessed the improvement as satisfactory, good or excellent in 18/19 (94.7%) cases. The protocol was considered efficient and practical by 18/19 (94.7%) and 19/19 (100%) owners, respectively, and the resulting good condition of skin and coat was emphasised by 15/19 (78.9%) owners.

CONCLUSIONS AND RELEVANCE

This topical protocol with Ophytrium-containing mousse and shampoo was well tolerated. The products were effective in reducing skin irritation and discomfort quickly and significantly in cats with skin irritation and pruritus, yielding high satisfaction levels among both veterinarians and owners.

A Scoping Review on Tyrosine Kinase Inhibitors in Cats: Current Evidence and Future Directions

Tyrosine kinase inhibitors (TKIs) have become invaluable in the treatment of human and canine malignancies, but their role in feline oncology is less defined. While toceranib phosphate and masitinib mesylate are licensed for use in dogs, no TKI is yet approved for cats. This review systematically maps the research conducted on the expression of tyrosine kinases in neoplastic and non-neoplastic domestic feline tissues, as well as the in vitro/in vivo use of TKIs in domestic cats. We identify and discuss knowledge gaps and speculate on the further research and potential indications for TKI use in cats. A comprehensive search of three electronic databases and relevant paper reference lists identified 139 studies meeting the inclusion criteria. The most commonly identified tumors were mast cell tumors (MCTs), mammary and squamous cell carcinomas and injection-site sarcomas. Based on the current literature, toceranib phosphate appears to be the most efficacious TKI in cats, especially against MCTs. Exploring the clinical use of TKIs in mammary carcinomas holds promise. Despite the progress, currently, the evidence falls short, underscoring the need for further research to discover new indications in feline oncology and to bridge the knowledge gaps between human and feline medicine.

Development and validation of an owner-assessed Visual Analog Scale for feline pruritus severity scoring (VAScat)

BACKGROUND

Assessment of the severity of pruritus is difficult in cats, because they manifest discomfort by increased licking, increased scratching or both.

HYPOTHESIS/OBJECTIVES

Our objective was to develop and validate a feline-specific pruritus scale (VAScat).

METHODS

The scale was designed as a double Visual Analog Scale (VAS), one VAS for licking and one for scratching, with severity and behavioural descriptors. The highest score (VAS-max) on either VAS was taken as the pruritus score for each cat. Owners of 153 cats with skin diseases and of 108 healthy cats scored their pet's pruritus using the VAScat. Ninety-six of 153 cats with skin diseases also were re-evaluated after four to eight weeks of treatment.

RESULTS

Pearson's correlation value between VAS-licking and VAS-scratching scores was r = 0.26 (p < 0.01), and Cronbach's alpha was 0.41. Both indexes indicated that the two scales measure different manifestations of pruritus and supported the use of a dual assessing system. Comparison with a numerical pruritus severity scale (0, absent; 1, mild; 2, moderate; 3, severe) suggested that VAS-licking and VAS-scratching scales taken alone are unsuitable for measuring absent to mild pruritus (grades 0-1), while VAS-max is (p = 0.001). VAS-licking, VAS-scratching and VAS-max all were suitable to assess higher levels of pruritus (grades 2-3, p < 0.01). The VAScat was able to measure pruritus improvement following therapy, as post-treatment scores were significantly decreased compared to pre-treatment ones (p < 0.0001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The VAScat proved to be a useful tool to assess pruritus in cats and for monitoring the response to treatment for pruritus.

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.

Jakinibs of All Trades: Inhibiting Cytokine Signaling in Immune-Mediated Pathologies

Over the last 25 years, inhibition of Janus kinases (JAKs) has been pursued as a modality for treating various immune and inflammatory disorders. While the clinical development of JAK inhibitors (jakinibs) began with the investigation of their use in allogeneic transplantation, their widest successful application came in autoimmune and allergic diseases. Multiple molecules have now been approved for diseases ranging from rheumatoid and juvenile arthritis to ulcerative colitis, atopic dermatitis, graft-versus-host-disease (GVHD) and other inflammatory pathologies in 80 countries around the world. Moreover, two jakinibs have also shown surprising efficacy in the treatment of hospitalized coronavirus disease-19 (COVID-19) patients, indicating additional roles for jakinibs in infectious diseases, cytokine storms and other hyperinflammatory syndromes. Jakinibs, as a class of pharmaceutics, continue to expand in clinical applications and with the development of more selective JAK-targeting and organ-selective delivery. Importantly, jakinib safety and pharmacokinetics have been investigated alongside clinical development, further cementing the potential benefits and limits of jakinib use. This review covers jakinibs that are approved or are under late phase investigation, focusing on clinical applications, pharmacokinetic and safety profiles, and future opportunities and challenges.

Atopic Dermatitis in Domestic Animals: What Our Current Understanding Is and How This Applies to Clinical Practice

Atopic dermatitis is a clinical syndrome that affects both people and animals. Dogs closely mimic the complexity of the human skin disease, and much progress has been made in recent years in terms of our understanding of the role of skin impairment and the identification of new treatments. Cats and horses also develop atopic syndromes which include both cutaneous and respiratory signs, yet studies in these species are lagging. It is now recognized that atopic dermatitis is not a single disease but a multifaceted clinical syndrome with different pathways in various subgroups of patients. Appreciating this complexity is clinically relevant as we develop more targeted treatments which may work well in some patients but not in others. Different phenotypes of atopic dermatitis have been described in dogs, and it is possible that phenotypes related to breed and age may exist in other animals similar to how they are described in people. The awareness of different mechanisms of disease leads to the desire to correlate different phenotypes with specific biomarkers and responses to treatment. In this review, the current understanding and updated information on atopic syndrome in animals are described, highlighting opportunities for further studies in the future.

Treatment of the feline atopic syndrome - a systematic review

BACKGROUND

Feline allergic skin disease and asthma occur regularly in small animal practice.

OBJECTIVES

To provide evidence-based recommendations for small animal practitioners on the treatment of feline atopic syndrome (FAS).

METHODS AND MATERIALS

The authors reviewed the literature available before February 2020, prepared a detailed evidence-based literature review and made recommendations based on the evaluated evidence.

RESULTS

Sixty-six papers and abstracts were identified describing treatment interventions for FAS and evaluated to establish treatment recommendations. For many treatment options, the papers were retrospective, open studies or case reports.

CONCLUSION AND CLINICAL RELEVANCE

In this review, there was good evidence for the efficacy of systemic glucocorticoids and ciclosporin, and limited evidence for the efficacy of topical glucocorticoids, oclacitinib and allergen-specific immunotherapy in feline atopic skin syndrome. Evidence pointed to low-to-moderate efficacy for antihistamines, fatty acids and palmitoyl ethanolamide. In feline asthma, there was good evidence for the efficacy of oral and inhaled glucocorticoids, and limited evidence of moderate efficacy for allergen-specific immunotherapy. Evidence supported low-to-moderate efficacy of mesenchymal stem cells, inhaled lidocaine and oclacitinib as treatments for feline asthma. For almost all therapeutic options (with the exception of glucocorticoids and ciclosporin), more randomised controlled trials are needed.

Successful Treatment of a Multi-Drug-Resistant Severely Pruritic Hypersensitivity Dermatitis in a Cat

A 3-year-old neutered female domestic shorthair cat was presented with a severely pruritic dermatitis. After exclusion of flea allergy dermatitis, ectoparasite infestation, retroviral infection, neoplasia, and cutaneous adverse food reaction, a diagnosis of nonflea, nonfood hypersensitivity dermatitis (NFNFHD) was made. The resolution of complicating bacterial infection and yeast overgrowth did not improve the animal's condition. Numerous antipruritic treatment modalities used during the investigation proved unsuccessful, including anti-inflammatory and immunosuppressive prednisolone doses, oclacitinib, antihistamines, ciclosporin A, and supplementation with essential fatty acids. Allergen-specific serology test results were negative. Treatment with oral dexamethasone allowed a complete resolution of clinical signs. The cat has been successfully maintained in remission for over 12 months. To the author's knowledge, this is the first case report of a cat with multi-drug-resistant NFNFHD treated successfully with dexamethasone.

Use of maropitant for the control of pruritus in non-flea, non-food-induced feline hypersensitivity dermatitis: an open-label, uncontrolled pilot study

OBJECTIVES

Non-flea, non-food-induced hypersensitivity dermatitis (NFNFIHD) is a common inflammatory and pruritic skin disease in cats. When avoidance and conventional systemic immunosuppressive treatments fail to control the clinical signs, there are limited treatment options. The aim of this study was to evaluate the efficacy and tolerability of maropitant in feline NFNFIHD.

METHODS

In an open-label, uncontrolled study, cats with proven non-seasonal NFNFIHD were treated with maropitant 2 mg/kg PO q24h for 4 weeks. Clinical lesions were evaluated with the Scoring Feline Allergic Dermatitis (SCORFAD) system and pruritus was evaluated with a 10 cm visual analogue scale (VAS) before and at the end of the study. Owners assessed global efficacy and tolerability with a 4-point scale at the end of the study. Adverse events and body weight changes were recorded.

RESULTS

Twelve cats were treated with a mean initial maropitant dose of 2.22 mg/kg PO q24h. The treatment decreased both SCORFAD and pruritus VAS (pVAS) scores in all cats except one, in which only pruritus was reduced. The efficacy and the tolerability of the treatment were judged as excellent or good by 83.3% of owners. Treatment did not cause any side effects other than, in a few cases, short-time, self-limiting sialorrhoea.

CONCLUSIONS AND RELEVANCE

Maropitant seems to be an effective, well-tolerated therapeutic option to control pruritus in cats. Caution is needed in interpreting the results as the pVAS score system has not yet been validated in cats and the trial was uncontrolled. A further, controlled study is required to confirm our findings.

A blinded, randomized, placebo-controlled trial of the safety of oclacitinib in cats

Background

Oclacitinib is a Janus kinase (JAK) 1 enzyme inhibitor and blocks JAK1-dependent cytokines and is used to control pruritus. Studies available in cats are very limited and as there is a potential role for oclacitinib in the control of pruritus in this specie, the aim of this study was to evaluate the safety and clinical effects of oral oclacitinib maleate in healthy cats.

Results

Thirty mixed-breed cats weighing from 2.1 to 5.3 kg each were randomly allocated to three treatment groups of 10 animals each. Cats in two groups received oclacitinib at 1 mg/kg or 2 mg/kg q 12 h orally for 28 days. Cats in the third group were given placebo tablets (cornstarch) q 12 h orally for 28 days. Oclacitinib maleate was well tolerated during the study and few adverse events were observed in treated cats. Clinical signs of toxicity were not observed in any animals treated at 1 mg/kg. Gastrointestinal clinical signs observed in the 2 mg/kg group included vomiting in two of the 10 cats and soft stools in two cats. One cat treated with placebo also exhibited soft stools. No significant differences were observed between the groups for hematologic analyses performed during the study. There was a slight increase in neutrophils and monocytes and a decrease in eosinophil mean counts in treated cats. Mean renal and liver enzymes remained normal throughout the entire study. A small, but significant increase in fructosamine levels was observed for both treated groups compared with placebo; however, values remained within the normal reference range. There were no significant difference between treated groups and the placebo group for urine specific gravity, pH, or urine protein to creatinine ratio mean values.

Conclusions

Oclacitinib maleate was well tolerated by cats at 1 mg/kg and 2 mg/kg and appeared to be safe for this species when administered orally twice daily for 28 days. More studies would be needed to demonstrate if oclacitinib maleate may be a suitable alternative to treat pruritic cats.

Feline hyperaesthesia syndrome with self-trauma to the tail: retrospective study of seven cases and proposal for an integrated multidisciplinary diagnostic approach

CASE SERIES SUMMARY

This was a retrospective study on the clinical features and response to treatment in seven cats with feline hyperaesthesia syndrome (FHS) and tail mutilation. FHS is a poorly understood disorder characterised by skin rippling over the dorsal lumbar area, episodes of jumping and running, excessive vocalisation, and tail chasing and self-trauma. The majority of the cats were young, with a median age of 1 year at the onset of clinical signs, male (n = 6) and with access to the outdoors (n = 5). Multiple daily episodes of tail chasing and self-trauma were reported in five cats, with tail mutilation in four cats. Vocalisation during the episodes (n = 5) and rippling of lumbar skin (n = 5) were also reported. Haematology, serum biochemistry, Toxoplasma gondii and feline immunodeficiency virus/feline leukaemia virus serology, MRI scans of brain, spinal cord and cauda equina, cerebrospinal fluid analysis and electrodiagnostic tests did not reveal any clinically significant abnormalities. A definitive final diagnosis was not reached in any of the cats, but hypersensitivity dermatitis was suspected in two cases. A variety of medications was used alone or in combination, including gabapentin (n = 6), meloxicam (n = 4), antibiotics (n = 4), phenobarbital (n = 2), prednisolone (n = 2) and topiramate (n = 2); ciclosporin, clomipramine, fluoxetine, amitriptyline and tramadol were used in one cat each. Clinical improvement was achieved in six cases; in five cats complete remission of clinical signs was achieved with gabapentin alone (n = 2), a combination of gabapentin/ciclosporin/amitriptyline (n = 1), gabapentin/prednisolone/phenobarbital (n = 1) or gabapentin/topiramate/meloxicam (n = 1).

RELEVANCE AND NOVEL INFORMATION

This is the first retrospective study on a series of cats with FHS. The diagnostic work-up did not reveal any significant abnormalities of the central or peripheral nervous system; dermatological and behavioural problems could not be ruled out. We propose an integrated multidisciplinary diagnostic pathway to be used for the management of clinical cases and for future prospective studies.

Atopic dermatitis in cats and dogs: a difficult disease for animals and owners

The purpose of this review article is to give an overview of atopic dermatitis in companion animals and of recent developments including knowledge on immunological background, novel treatment options and difficulties in disease management. The prevalence of hypersensitivities seems to be increasing. The pathogenetic mechanisms are not fully understood, yet multiple gene abnormalities and altered immunological processes are involved. In dogs and cats, the diagnosis of atopic dermatitis is based on history, clinical examination and exclusion of other differential diagnoses. Intradermal testing or testing for serum allergen-specific Immunoglobulin E is only used to identify allergens for inclusion in the extract for allergen immunotherapy. Symptomatic therapy includes glucocorticoids, ciclosporin, essential fatty acids and antihistamines. A selective janus kinase 1 inhibitor and a caninized monoclonal interleukin-31 antibody are the newest options for symptomatic treatment, although longterm effects still need to be assessed. The chronic and often severe nature of the disease, the costly diagnostic workup, frequent clinical flares and lifelong treatment are challenging for owners, pets and veterinarians. Patience and excellent communication skills are needed to achieve a good owner compliance and satisfactory clinical outcome for the animal.

Cannabinoid receptor types 1 and 2 and peroxisome proliferator-activated receptor-α: distribution in the skin of clinically healthy cats and cats with hypersensitivity dermatitis

BACKGROUND

Cannabinoid receptors and peroxisome proliferator-activated receptor-alpha (PPAR-α) are gaining recognition as potential therapeutic targets for the treatment of skin disorders.

HYPOTHESIS/OBJECTIVES

The aim of this study was to investigate the distribution of cannabinoid type 1 and 2 receptors (CBR1 and CBR2) and PPAR-α in feline skin and verify whether changes occur in the course of hypersensitivity dermatitis.

ANIMALS

Twelve privately owned cats. Skin samples were obtained from five healthy cats with no skin lesions and seven cats clinically diagnosed with hypersensitivity dermatitis.

METHODS AND MATERIALS

Haematoxylin and eosin stained skin sections were investigated for histopathological changes. Indirect immunofluorescence for CBR1, CBR2 and PPAR-α was performed on paraffin-embedded sections, and antibody specificity tested by Western blot analysis.

RESULTS

Skin samples from cats with hypersensitivity dermatitis were all histopathologically diagnosed with eosinophilic dermatitis. CB receptors and PPAR-α were distributed throughout the skin in both healthy and allergic cats. In normal feline skin, these receptors were mainly distributed in the epithelial compartment. Receptor expression increased in hypersensitivity compared to healthy skin, with the main distribution changes being suprabasal for CBR1, dermal for CBR2 and marked expression of PPAR-α in hyperplastic epidermis and perivascular infiltrate.

CONCLUSIONS AND CLINICAL IMPORTANCE

Increased expression of cannabinoid receptors in the skin of cats with hypersensitivity dermatitis suggests an endogenous protective strategy and may support the use of natural cannabinoid receptor or PPAR-α agonists to treat feline hypersensitivity dermatitis.

Atopic Dermatitis in Animals and People: An Update and Comparative Review

Atopic dermatitis is an extremely common, pruritic, and frustrating disease to treat in both people and animals. Atopic dermatitis is multifactorial and results from complex interactions between genetic and environmental factors. Much progress has been done in recent years in terms of understanding the complex pathogenesis of this clinical syndrome and the identification of new treatments. As we learn more about it, we appreciate the striking similarities that exist in the clinical manifestations of this disease across species. Both in animals and people, atopic disease is becoming increasingly common and important similarities exist in terms of immunologic aberrations and the propensity for allergic sensitization. The purpose of this review is to highlight the most recent views on atopic dermatitis in both domestic species and in people emphasizing the similarities and the differences. A comparative approach can be beneficial in understanding the natural course of this disease and the variable response to existing therapies.

Cutaneous Hypersensitivity Dermatoses in the Feline Patient: A Review of Allergic Skin Disease in Cats

Feline allergic skin disease presents a unique set of challenges to the veterinary practitioner. Although there is some similarity to what is seen in the allergic canine patient, cutaneous hypersensitivity dermatoses in cats can manifest with strikingly different clinical signs, treatment options and outcomes, and secondary complications/disease entities. Additionally, less is known about the pathogenesis of feline allergic skin diseases, particularly "feline atopic syndrome" when compared to dogs or people. This article aims to review what is currently known in regards to allergic skin disease in the feline patient, with focus on non-flea, non-food hypersensitivity dermatitis.