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

Pharmacology of drugs used in autoimmune dermatopathies in cats and dogs: A narrative review

Immunosuppressive drugs are the mainstay of treatment for many feline and canine autoimmune skin diseases, either as monotherapy or in combination with other drugs. Treatment with these drugs is often lifelong and may have long-term consequences on the affected animal's overall quality-of-life. Clinicians need to understand the pharmacology of immunosuppressants in planning and executing the treatment regimen for the best possible clinical outcome, as well as reducing the risk of adverse effects. This review paper will focus on the mechanism of action, pharmacokinetics and pharmacodynamics, clinical uses and adverse effects of immunosuppressive drugs used to treat autoimmune dermatoses in cats and dogs. These include glucocorticoids, ciclosporin A, azathioprine, chlorambucil, mycophenolate mofetil, oclacitinib and Bruton's tyrosine kinase inhibitors.

Evidence-base for the beneficial effect of nutraceuticals in canine dermatological immune-mediated inflammatory diseases - A literature review

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are associated with an abnormal immune response, resulting in a disturbed homeostasis and chronic inflammation. Most canine dermatological IMIDs (cDIMIDs), such as allergies, autoimmune and immune-mediated diseases, require long-term treatment with immunosuppressive drugs with potential adverse effects. In general, nutraceuticals are thought to be safe. As a result, there is a tendency for the more frequent use of nutraceuticals in veterinary medicine.

OBJECTIVES

The aim of this review was to present evidence-based proof for the use of various nutraceuticals in the treatment of cDIMIDs and, where possible, to provide conclusions to guide their use in veterinary dermatological practice.

METHODS

A comprehensive literature search on common cDIMIDs and nutraceuticals was performed. Only peer-reviewed articles published in English and related to the study topic were included. A total of 64 eligible publications were classified in five categories based on study design and substantively assessed on additional criteria such as standardisation of diets and number of included animals. For final appraisal, classification of major, minor or no evidence was used whereby efficacy was based on clinical outcome measurements.

CONCLUSIONS

Minor evidence for the beneficial use of several nutraceuticals, including essential fatty acids, niacinamide and probiotics, was found for treatment of specific cDIMIDs. These nutraceuticals may improve clinical signs or reduce the required dose of concurrent medication (e.g. drug-sparing effect) in some dogs. Some nutraceuticals also may be used for long-term maintenance therapy. Despite some promising findings, major evidence for the use of nutraceuticals in cDIMIDs is lacking, warranting further research.

Comparison of three canine nose guards for reduction of ultraviolet (UVA and UVB) solar radiation

BACKGROUND

Protection from solar ultraviolet (UV) radiation is paramount for some dermatological conditions, yet there are no studies assessing UV nose guards for dogs.

OBJECTIVES

Compare the ability of three nasal guards to block solar UV radiation (UVR) from the canine nose, using two commercial products and one created by the authors.

ANIMALS

Four fabric model dogs were used in this prospective controlled trial.

MATERIALS AND METHODS

Each model had a UV dosimeter applied to the dorsal nose and anterior nasal planum. Three models had nose protectors applied: (1) a mesh hood (OutFox Field Guard, OutFox For Dogs); (2) a fabric nose shield (Nose Protector, Dog Nose Protectors); or (3) a basket muzzle with ultraviolet protection factor (UPF) 50+ fabric developed by the authors. The control had no protective device applied. All the models were placed in direct sunlight and measurements taken over nine 2 h time periods. Total cumulative UVR was analysed for each location and type of guard or control.

RESULTS

All guards provided statistically significant UV protection compared to control at all time points (p < 0.001). The basket muzzle with UPF 50+ guard was consistent in protecting the dorsal and anterior nose, blocking 94.2% and 94.3% UVR, respectively. The fabric nose protector blocked 99.2% UVR from the dorsal and 82.9% anterior. The mesh hood blocked 72.5% of UVR dorsal and 71.4% anterior.

CONCLUSIONS AND CLINICAL RELEVANCE

Two guards were superior in blocking UVR; however, the choice of UV guard in a clinical setting depends on an individual's disease location and tolerance of the device.

Successful Treatment of Mucocutaneous Lupus Erythematosus in a Dog with Prednisolone, Mycophenolate Mofetil and Tacrolimus

A 6-year-old, intact male miniature Pinscher dog had erosive lesions on perilabial, peripenial and perianal mucocutaneous areas, which were exacerbated by ulcerations, crusts, with pain while defecating and urinating. The lesions were symmetrical, and no systemic signs were observed. Histopathological evaluation showed parakeratotic hyperkeratosis, ulceration and cell-rich lymphoplasmacytic interface dermatitis with basal keratinocyte apoptosis. Immunohistochemistry revealed strong reaction in the dermoepidermal junction against goat-canine IgG and mild-to-moderate reaction against goat-canine IgA, IgM and C3. Based on these findings, the dog was diagnosed with mucocutaneous lupus erythematosus (MCLE). Oral prednisolone 1 mg/kg twice daily, mycophenolate mofetil (MMF) 18.3 mg/kg twice daily and 0.1% tacrolimus ointment were prescribed as initial treatment. The lesions showed remarkable improvement within 4 weeks, but the dog exhibited polyuria, polydipsia and hepatomegaly with high dosage of prednisolone. Hence, the dosage of prednisolone was gradually tapered for 9 weeks and discontinued, but MMF and tacrolimus were continued. No new lesion or associated side effect was observed while reducing the MMF dose to 10 mg/kg twice daily and with continuous use of tacrolimus ointment after steroid discontinuation. In conclusion, this case report emphasizes the usefulness of MMF and tacrolimus as steroid-sparing agents in the treatment of dogs with MCLE. To the best of our knowledge, this is the first case report of MCLE that was successfully managed long-term with MMF and tacrolimus.

Cutaneous lupus erythematosus in dogs: a comprehensive review

Since the first description of discoid lupus erythematosus (LE) in two dogs in 1979, the spectrum of canine cutaneous lupus erythematosus (CLE) variants has expanded markedly.

In this review, we first propose an adaptation of the Gilliam-Sontheimer classification of CLE for dogs. We then review the signalment, clinical signs, laboratory and histopathology and treatment outcome of the currently recognized variants of canine CLE, which are vesicular CLE, exfoliative CLE, mucocutaneous LE and facial or generalized discoid LE. We end with a short description of the rare cutaneous manifestations of systemic LE in dogs.

Canine CLE variants are heterogeneous, some of them mirror their human counterparts while others appear—thus far—unique to the dog. As most CLE subtypes seem to have a good prognosis after diagnosis, veterinarians are encouraged to become familiar with the spectrum of often-characteristic and unique clinical signs that would permit an early diagnosis and the rapid implementation of an effective treatment.

Therapeutic effectiveness of calcineurin inhibitors in canine vesicular cutaneous lupus erythematosus

BACKGROUND

Oral and topical calcineurin inhibitors (CIs) have been reported to lead to complete lesion remission in several dogs with vesicular cutaneous lupus erythematosus (VCLE).

OBJECTIVES

To report retrospectively on the effectiveness and adverse effects of systemic (ciclosporin) and/or topical (tacrolimus/pimecrolimus) CIs in 11 dogs with VCLE.

METHODS

Inclusion criteria were: (i) presence of characteristic annular, polycyclic or serpiginous ulcerations distributed over the groin, axillae and/or ventral abdomen; (ii) a histopathological diagnosis of VCLE (i.e. a lymphocyte-rich interface dermatitis with vesiculation); (iii) treatment that included CIs for at least eight weeks; and (iv) follow-up until death/euthanasia or for a minimum of 12 months post-diagnosis.

RESULTS

Initial therapy included the avoidance of excessive sun exposure, oral glucocorticoids [six of 11 dogs (55%); progressively tapered over a month] and once daily ciclosporin [11 dogs (100%); median 5.8 mg/kg]. A complete remission (CR) of signs occurred between days 35 and 70 after starting CIs in eight dogs (73%); increasing ciclosporin dosage and adding topical tacrolimus induced a CR in two additional dogs (18%). Relapses were common when doses were tapered or discontinued. With the exception of three dogs that were euthanized, clinical signs were maintained in CR with oral ciclosporin (eight of eight dogs treated, 100%) or topical tacrolimus/pimecrolimus (four of eight dogs; 50%) with a median follow-up of 2.9 years.

CONCLUSIONS AND CLINICAL IMPORTANCE

These observations support CIs as the preferable therapeutic alternatives to long-term immunosuppression with oral glucocorticoids in dogs with VCLE.

Generalized Canine Discoid Lupus Erythematosus Responsive to Tetracycline and Niacinamide Therapy

Discoid lupus erythematosus (DLE) is a commonly reported canine autoimmune disease that normally presents with a phenotype consisting of erythema, depigmentation, scaling, erosions/ulcers, and scarring over the nasal planum and the proximal dorsal muzzle. Recently, two cases of a generalized variant of this disease have been reported, whose lesions responded to either systemic glucocorticoids or a combination of topical corticosteroids, topical tacrolimus, and the oral antimalarial hydroxychloroquine. The purpose of this report is to describe an 11 yr old shih tzu that presented with skin lesions consisting of multiple annular, erythematous papules and plaques, hyperpigmentation, adherent scaling, and atrophic scars over the caudal dorsum, flanks, craniodorsal thorax, and lateroproximal extremities. A diagnosis of generalized DLE was made based on the clinical presentation, histopathology, laboratory values, and direct immunofluorescence findings. Treatment consisted of oral tetracycline and oral niacinamide, which resulted in complete remission of clinical signs. This is the first documented report of generalized canine DLE responding to the described immunomodulating regimen. Such a combination might therefore be considered as a glucocorticoid and/or antimalarial alternative for the management of generalized DLE.

Ciclosporin therapy for canine generalized discoid lupus erythematosus refractory to doxycycline and niacinamide

BACKGROUND

Generalized discoid lupus erythematosus (DLE) is an autoimmune skin disease variant rarely reported in dogs. The antimalarial immunomodulator hydroxychloroquine has been suggested as maintenance therapy for generalized DLE in one dog, but several recurrences were noted in the 1 year follow-up of that patient.

HYPOTHESIS/OBJECTIVE

To describe the effective treatment of generalized DLE with ciclosporin in one dog.

ANIMAL

A 6-year-old, castrated male crossbred dog was presented with pruritic, well-demarcated annular to polycyclic, hyperpigmented plaques with marginal erythema on the dorsal head, neck, trunk and medial extremities; these had been nonresponsive to treatment with doxycycline and niacinamide.

METHODS

Investigation included complete blood count, serum chemistry profile, urinalysis, serum antinuclear antibody test, histopathological examination and direct immunofluorescence testing of skin biopsies.

RESULTS

The presence of lymphocyte-rich interface dermatitis on histology, together with generalized chronic recurrent hyperpigmented plaques, was consistent with the diagnosis of a generalized variant of DLE. The absence of systemic signs and unremarkable laboratory tests excluded concurrent systemic lupus erythematosus. Treatment was initiated with oral dexamethasone and ciclosporin. After 1 month, dexamethasone was discontinued and oral ketoconazole was added to the therapeutic regimen. Four months later, pruritus and erythema resolved, with most skin lesions becoming impalpable. Over the last 6 months, the patient's DLE was maintained in remission with oral ciclosporin and ketoconazole in combination every 3 days.

CONCLUSIONS AND CLINICAL IMPORTANCE

The combination of ciclosporin and ketoconazole appeared effective to induce and maintain lesion remission in this dog with generalized DLE.

Successful treatment of a novel generalized variant of canine discoid lupus erythematosus with oral hydroxychloroquine

Discoid lupus erythematosus (DLE) is a common canine autoimmune disease that usually manifests as a localized ulcerative and scarring nasal dermatitis. We report herein a generalized variant of canine DLE successfully treated with the antimalarial immunomodulator hydroxychloroquine (HCQ). A 9-year-old hairless Chinese crested dog was presented with annular and polycyclic hyperpigmented and scaly skin lesions with central erosions, hypopigmentation and/or scarring on the trunk, neck and lateral extremities. Associated systemic signs were not seen. The clinical diagnosis of generalized DLE was supported by the demonstration of lymphocyte-rich interface dermatitis with epidermal atrophy and dermo-epidermal deposition of immunoglobulins and activated complement. As for human DLE, treatment was initiated with HCQ at 5 mg/kg once daily along with 2 weeks of 0.1% tacrolimus ointment and restriction of sun exposure. Over the following year, complete remission was maintained with HCQ at 5 mg/kg orally once daily with the exception of three relapses; two occurred during treatment induction and the third arose when the frequency of HCQ administration was reduced to every other day. Disease flares were controlled with 0.1% tacrolimus ointment alternating with 0.1% prednicarbate cream once daily for 5-10 days. Altogether, adverse drug events were not seen with this regimen. In summary, clinically, histologically and immunologically, this dog's disease mirrored the generalized discoid variant of chronic cutaneous lupus erythematosus of humans. The apparent benefit of HCQ, its safety and low cost warrant future investigations of its use for treatment of canine cutaneous lupus variants.

Evaluation of four topical preparations for the treatment of cannon hyperkeratosis in a horse

The response to treatment with four topical preparations was evaluated in an 11-year-old Morgan horse mare with histologically confirmed quadrilateral cannon hyperkeratosis. Each limb was treated for 30 days with 0.1% tacrolimus ointment, 0.1% adapalene gel, 0.2% phytosphingosine spray or a water-based emollient. Response to treatment was evaluated both histologically and visually. A water-based emollient and 0.1% tacrolimus ointment produced encouraging clinical responses. Pre-treatment histopathology identified marked, mostly compact, hyperkeratosis and follicular hyperkeratosis, most prominent in the infundibular area. Following treatment, histopathology identified a mild reduction in follicular keratin production and stratum corneum thickness.

Topical 0.03% tacrolimus for treatment of pemphigus erythematosus in a Korea Jindo dog

Topical 0.03% tacrolimus was used for treatment of a Korea Jindo dog diagnosed with pemphigus erythematosus. The dog was slowly improved following application of tacrolimus but did not achieve complete remission until end of this study. No adverse effects on clinical or laboratory parameters were noted during the topical tacrolimus therapy period.

Proliferative and necrotizing otitis externa in four cats

Proliferative and necrotizing feline otitis externa is a rare disorder of unknown aetiology. This condition was diagnosed by skin biopsy in three adult domestic shorthair cats (3-5 years old) and one kitten (6 months old). The affected cats had large tan to dark brown-black coalescing plaques covering the concave surface of the pinnae and external ear canals. Friable material from the plaques and a thick exudate occluded the ear canals. The cats had a secondary bacterial and/or yeast otitis. Prior to the histopathological diagnosis, all cats received numerous otic preparations as well as oral antibiotics and corticosteroids without resolution. Histologically, all cases had strikingly similar changes; acanthosis with pronounced hair follicle outer root sheath hyperplasia and neutrophilic luminal folliculitis, follicular keratosis and individually necrotic keratinocytes in the outer root sheath of hair follicles. One case was documented via skin biopsy to have persisted for 4 years. The adult cats were treated with topical 0.1% tacrolimus and all showed marked improvement although one cat was lost to follow up. The lesions completely resolved with topical tacrolimus alone in one cat and topical tacrolimus in addition to oral prednisolone in another cat.

A review of autoimmune skin diseases in domestic animals: I - superficial pemphigus

In humans, the pemphigus denomination encompasses a group of autoimmune blistering skin diseases with intraepidermal separation resulting from cell-cell detachment by acantholysis. Entities are classified based on the level of blistering in the epidermis, and both superficial (pemphigus foliaceus, IgA pemphigus) and deep (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) variants are recognized. In domestic animals, subsets of pemphigus have been recognized since the mid-1970s, and the disease classification resembles that used for human patients. This article reviews up-to-date knowledge on the epidemiology, clinical signs, histopathology, immunopathology and treatment outcome of superficial pemphigus in domestic animals. Detailed information on canine, feline, equine and caprine pemphigus foliaceus, canine and feline pemphigus erythematosus and canine panepidermal pustular pemphigus is provided.

Practical Applications of Topical Therapy for Allergic, Infectious, and Seborrheic Disorders

Topical therapy is extremely important in the management of allergic, infectious, and seborrheic disorders. It can be used as a sole therapy or adjunctive therapy for these disorders, often minimizing the need for systemic therapy. In allergic diseases, pruritus can be decreased by removing allergen, desensitizing the skin or other antipruritic effects. Many agents can also maintain or replace moisture to the skin and have emollient effects. When used for infectious conditions, topical therapy can decrease microbial counts and reduce surface colonization of microbes and help to prevent relapses. Antiseborrheic products function by normalizing keratinocyte turnover rates by reducing epidermal division (keratoplastic), normalizing keratinization, and increasing desquamation (keratolytic). There are many different topical vehicles and modes of application: shampoos, whirlpools, soaks, rinses, sprays, lotions, gels, creams, and ointments. Shampoos are often the most practical and effective. The practitioner needs to become familiar with many active ingredients to learn what products are indicated for specific diseases.

Effect of topical 0.02% tacrolimus aqueous suspension on tear production in dogs with keratoconjunctivitis sicca

OBJECTIVE

To investigate the effect of 0.02% tacrolimus in aqueous suspension on tear production in dogs with keratoconjunctivitis sicca (KCS). Animals studied One hundred five dogs diagnosed with KCS [Schirmer tear test (STT) < or = 10 mm/min and clinical signs of dry eye]. Eyes with marginally decreased STT (11 < or = 15 mm/min) and clinical signs of dry eye were also evaluated.

PROCEDURE

The investigation was conducted in two parts: an initial efficacy study and a subsequent double blinded controlled study. In the efficacy study, the effect of topical tacrolimus (formerly FK-506) on tear production in dogs with primary KCS was evaluated. Dogs were divided into four categories: 1) 59 eyes (38 dogs) naïve to tear stimulation therapy with initial STT < or = 10 mm/min; 2) 28 eyes (21 dogs) naïve to tear stimulation therapy with initial STT 11 < or = 15 mm/min; 3) 30 eyes (15 dogs) maintained successfully on CsA therapy; 4) 47 eyes (24 dogs) unresponsive to CsA therapy. STT and clinical signs were evaluated prior to and after 6 to 8 weeks of twice daily tacrolimus administration. Tacrolimus was substituted for CsA therapy in categories 3 and 4. The controlled study compared the effect of topical tacrolimus in aqueous suspension to administration of the aqueous carrier alone on tear production in 20 dogs with primary KCS.

RESULTS

In the efficacy study, STT increased by 5 mm/min in 84.7%, 25.0%, 26.7% and 51.1% of eyes in categories 1, 2, 3 and 4 respectively after tacrolimus administration. Eighty-three percent of eyes with extremely low initial STT (< or = 2 mm/min), increased 5 mm/min after tacrolimus. In the controlled study, STT increased by 5 mm/min in 7/10 dogs (14/20 eyes) that received tacrolimus and in none of the 10 dogs that received aqueous carrier alone. Dogs receiving just the aqueous carrier were subsequently treated with tacrolimus, and STT increased 5 mm/min in 9 dogs (18/20 eyes) after administration.

CONCLUSIONS

Twice daily administration of 0.02% tacrolimus in aqueous suspension effectively increased tear production in dogs with KCS. Topical tacrolimus is a promising alternative to topical CsA for treatment of KCS and may be beneficial in patients with less than optimal response to topical CsA.

Pemphigus: current therapy

Pemphigus is an autoimmune skin disease that can present in a variety of forms and can be a challenging disease to manage and treat. An overview of the different forms of pemphigus and diagnostics are discussed including pemphigus foliaceus (PF), pemphigus erythematosus (PE), panepidermal pustular pemphigus (PPP), pemphigus vulgaris (PV) and paraneoplastic pemphigus (PNP). Emphasis on therapy is presented. Included are the most current commonly used therapeutics (glucocorticoids, azathioprine, chlorambucil and tetracycline and niacinamide); current alternative therapeutics (cyclosporin and tacrolimus and mycophenolate mofetil) and additional alternative therapeutics (cyclophosphamide, chrysotherapy, dapsone, sulfasalazine and intravenous immunoglobulin (IVIG) therapy).