Prospective open pilot study on the use of ciclosporin for feline allergic skin disease

OBJECTIVES: To evaluate the efficacy of ciclosporin in cats with allergic skin disease. METHODS: Ten cats with signs of allergic skin disease were administered ciclosporin daily at a dose of 3.6 to 8.3 mg/kg for one month. None of these cats had previously responded to a hypoallergenic diet trial, and all animals had previously been treated with endectoparasiticidal drugs, with no improvement two weeks before entering the trial. On days 0 and 30, owners assessed pruritus with a visual analogue scale, and veterinarians evaluated cutaneous lesions. RESULTS: All the cats had pruritus and erythema, five had alopecia, two had an eosinophilic plaque, one had miliary dermatitis and two had both alopecia and an eosinophilic plaque. Good or excellent improvement was observed in 40 per cent of cats for pruritus, 57 per cent of cats for alopecia and 60 per cent of cats for erythema. A significant decrease in mean scores was observed for pruritus only, while for erythema and alopecia, it was close to being significant (P < 0.052). CLINICAL SIGNIFICANCE: Ciclosporin may be helpful in symptomatically treating signs of feline allergic skin disease. However, it is important to remember that ciclosporin is not licensed for use in cats.     

Responsiveness and validity of the SCORFAD, an extent and severity scale for feline hypersensitivity dermatitis

Background – Hypersensitivity (allergic) dermatitis (HD) is commonly seen in cats, causing pruritus and various patterns of skin lesions, including at least one of the following: head and neck excoriations, self‐induced alopecia, eosinophilic plaques and miliary dermatitis. Few studies have evaluated the efficacy of therapeutic interventions for feline HD, and although various scales have been considered, none has been formally validated for the assessment of disease severity and its response to therapy. Objective – To design and validate a novel scale (SCORing Feline Allergic Dermatitis; SCORFAD) to assess the value of different criteria used as outcome measures for the treatment of feline HD and to set minimal thresholds for defining the clinical success of tested interventions. Animals – One hundred client‐owned cats. Methods – The SCORFAD scale was designed to include the four most frequently identified lesion types in feline HD (eosinophilic plaque, head and neck excoriations, self‐induced alopecia and miliary dermatitis) across 10 body regions. The extent and severity of each lesion type were graded prior to inclusion and after 3 and 6 weeks in a clinical study to compare the efficacy of two doses of ciclosporin with placebo. Results – The SCORFAD scale was found to exhibit satisfactory content, construct, criterion and sensitivity to change. The percentage reduction in SCORFAD from baseline was determined to be the most valid assessment of clinical response. Inter‐ and intra‐observer reliability was not assessed. Conclusions and clinical importance – The SCORFAD scale is proposed for use as a validated tool for the assessment of disease severity and response to therapeutic interventions in clinical trials for feline HD.     

Serum allergen‐specific immunoglobulin E in atopic and healthy cats: comparison of a rapid screening immunoassay and complete‐panel analysis

Feline and canine atopic dermatitis are thought to have a similar immunopathogenesis. As with dogs, detection of allergen‐specific IgE in cat serum merely supports a diagnosis of feline atopy based on compatible history, clinical signs and elimination of other pruritic dermatoses. In this study, a rapid screening immunoassay (Allercept^® E‐Screen 2nd Generation; Heska AG, Fribourg, Switzerland; ES2G) was compared with a complete‐panel serum allergen‐specific IgE assay (Allercept^®; Heska AG; CP) in healthy cats with no history of skin disease and in atopic cats. The latter had no diagnosis of external parasitism, infection, food hypersensitivity or other skin disease explaining their pruritus, and expressed cutaneous reaction patterns typically associated with feline allergic skin disease (head, neck or pinnal pruritus, miliary dermatitis, self‐induced alopecia, eosinophilic granuloma complex). The proportion of cats positive on either the ES2G or the CP assays was not significantly different between the atopic and healthy cat groups. There was, however, strong agreement between the results of the ES2G and CP assay; overall, the two tests were in agreement for 43 of 49 (88%) serum samples. There was also strong agreement when individual allergen groups were evaluated (agreement noted: indoor, 41 of 49 samples; grasses/weeds, 37 of 49 samples; and trees, 41 of 49 samples). These results indicate that although neither test is diagnostic for feline atopic dermatitis, the screening assay is beneficial for predicting the results of a complete‐panel serum allergen‐specific IgE assay in cats.     

The Use of Megestrol Acetate in Some Feline Dermatological Problems

Twenty-one cats were treated with megestrol acetate because they were showing clinical signs associated with one of the following problems: eosinophilic ulcer, eosinophilic plaque, neurodermatitis, endocrine alopecia and miliary dermatitis. The dosage schedule was 5 mg orally per day per cat for seven days, then 5 mg every three days for 21 days.

In all cats, we noted a good improvement of the lesions as soon as treatment was started. In 25% of the patients, one treatment schedule was sufficient to control the skin disease for at least 18 months. In the remaining 75%, two treatment schedules and/or a maintenance dosage had to be established.

Side effects encountered were increased appetite, personality changes and depression.

     

Sézary syndrome in a cat

Sézary syndrome is an uncommon leukemic variant of cutaneous lymphoma in cats. This cat had recurrent dermatitis with erythematous, pruritic plaques. Multiple skin imprints and biopsy samples were obtained over a 6-month period, and histopathological findings were consistent initially with eosinophilic miliary dermatitis and later with erythema multiforme. One week before death, Sézary cells were identified in the peripheral blood that expressed cluster of differentiation (CD)3 and CD8 antigens. Massive infiltration of CD3+ lymphocytes was noted in the skin and multiple internal tissues by histopathological examination. This case demonstrates the difficulty in diagnosing cutaneous lymphoma early in the disease course.     

Interleukin 4-producing CD4+ T cells in the skin of cats with allergic dermatitis

Lesional skin of cats with allergic dermatitis has a cellular infiltrate and a CD4/CD8 ratio comparable to that in humans with atopic dermatitis. CD4+ helper T cells and in particular cells belonging to the Th2 subset play an important role in disease pathogenesis in humans. We investigated the cytokine pattern of CD4+ T cells in situ, with special emphasis on the putative presence of cells producing interleukin 4 (IL4), in cats with allergic dermatitis. Immunohistochemical procedures were used to determine that CD4+ T cells in lesional and nonlesional skin of cats with allergic dermatitis can produce IL4, as occurs in humans. Lesional and nonlesional skin of cats with allergic dermatitis had significantly more IL4+ T cells (P = 0.001) than did skin of healthy control cats. Double staining indicated that all IL4+ cells were positive for pan-T or CD4 markers. Double labeling for mast cell chymase and IL4 stained primarily different cells. Western blotting demonstrated cross-reactivity between the antibody against human IL4 and a feline recombinant IL4. These results indicate that IL4 is primarily produced by CD4+ T cells and is also present in clinically uninvolved skin, indicating a role in the pathogenesis of allergic dermatitis in cats.     

Mosquito bite-caused eosinophilic dermatitis in cats.

Eight cats had lesions on the nasal bridge, ears, and footpads, with histologic and hematologic features of a recently described seasonal form of eosinophilic granuloma complex. Four cats were examined in detail, and it was established that 2 of the 4 reacted to mosquito extract on intradermal skin testing read at 20 minutes. Neither of the 2 cats tested had deposits of immunoglobulins in lesional or perilesional skin. Lesions on all 4 cats resolved when kept at home behind insect screening, but flared up if the screening was removed. Mosquitoes that were observed to be biting and causing lesions were collected and identified. Other species of laboratory-reared mosquitoes were allowed to bite nonlesional skin of 1 affected cat, causing pruritus, erythematous crusting, and ulcerative lesions at the bite site, which was characterized histologically as eosinophilic dermatitis.     

Establishment of diagnostic criteria for feline nonflea-induced hypersensitivity dermatitis

Hypersensitivity dermatitides (HD) are commonly seen in cats, and they are usually caused by environmental, food and/or flea allergens. Affected cats normally present with one of the following clinical reaction patterns: head and neck excoriations, usually symmetrical self-induced alopecia, eosinophilic skin lesions or miliary dermatitis. Importantly, none of these clinical presentations is considered to be pathognomonic for HD skin diseases, and the diagnosis of HD is usually based on the exclusion of other pruritic diseases and on a positive response to therapy. The objectives of this study were to propose sets of criteria for the diagnosis of nonflea-induced HD (NFHD). We recruited 501 cats with pruritus and skin lesions and compared clinical parameters between cats with NFHD (encompassing those with nonflea, nonfood HD and those with food HD), flea HD and other pruritic conditions. Using simulated annealing techniques, we established two sets of proposed criteria for the following two different clinical situations: (i) the diagnosis of NFHD in a population of pruritic cats; and (ii) the diagnosis of NFHD after exclusion of cats with flea HD. These criteria sets were associated with good sensitivity and specificity and may be useful for homogeneity of enrolment in clinical trials and to evaluate the probability of diagnosis of NFHD in clinical practice. Finally, these criteria were not useful to differentiate cats with NFHD from those with food HD.     

Immunophenotyping of the cutaneous cellular infiltrate after atopy patch testing in cats with atopic dermatitis

Cats with spontaneously occurring atopic dermatitis have clinical and immunocytochemical characteristics compatible with these in humans with atopic dermatitis (AD). The atopy patch test (APT) has proven to be a valuable tool in elucidating the disease process in humans. Additionally, the APT is very specific and bypasses the problem of conflicting results due to differences in chronicity of lesions of AD patients. We adapted the APT for use in cats to explore the suitability of the APT as a tool to study the onset of allergic inflammation in cats with atopic dermatitis. APT were performed in AD cats (n = 6) and healthy cats (n = 10). All cats were patch tested with two allergens in three different dilutions and a diluent control. The allergens for the APT were selected from positive intradermal test and /or prick test results and consisted of: Dermatophagoides farinae, D. pteronyssinus, Tyrophagus putrescentiae, and a grass pollen mixture. APT were read after 10, 24 and 48 h, and punch biopsies for immunohistochemical evaluation were collected at these time points. Macroscopically positive APT reactions were observed in three out of six cats at 24 and/or 48 h with allergen concentrations of 25,000 and 100,000 NU/ml. Reactions were not observed at negative control sites and neither in control animals. A significantly increased number of IL-4+, CD4+, CD3+, MHC class II+ and CD1a+ cells was found in one AD cat with positive APT reactions. Five out of six AD cats had significantly increased IL-4+ T cell numbers at 24 and/or 48 h. Our data indicate that in cats, macroscopically positive patch test reactions can be induced, which have a cellular infiltrate similar to that in lesional skin. We found a high specificity and a macroscopically positive APT reaction in half of the cats, which is similar to what is seen in humans. Hence, the APT in cats might be a useful tool in studying the immunopathogenesis of feline atopic dermatitis.     

Measurement of serum immunoglobulin E (IgE) specific for house dust mite antigens in normal cats and cats with allergic skin disease

The purpose of this study was to determine whether cats with allergic skin disease have significant concentrations of serum Immunoglobulin E (IgE) specific for antigens derived from the house dust mites (HDM) Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus (DP). Enzyme-linked immunosorbent assays (ELISA) were developed for this purpose. Binding of serum allergen-specific IgE was detected via the use of biotinylated Fc-epsilon receptor alpha chain protein (FcvarepsilonRIalpha). Following optimisation of the assay, serum samples from 59 cats with allergic skin disease and 54 clinically normal cats were screened. Results were expressed as ELISA units per ml (EU/ml) compared to a standard curve. Serological findings were correlated with the clinical presentation of affected cats. Cats with symptoms of feline allergic skin disease were grouped as follows: self-induced alopecia without lesions (group 1), papulocrusting dermatitis (group 2), eosinophilic granuloma complex (group 3), papular/ulcerative dermatitis of head and neck/facial dermatitis (group 4), and a combination of symptoms (group 5). Control normal cats comprised the final group (group 6). The Kruskal-Wallis test was used for statistical analysis. There was no significant difference between groups for DF- and DP-specific IgE concentrations with a p-value of 0.875 and 0.705, respectively. Although the FcvarepsilonRIalpha-based ELISA was able to detect house dust mite-specific feline IgE, the presence of this allergen-specific IgE correlates poorly with the presence of clinical manifestations of allergic skin disease. The results of this study question the clinical relevance of house dust mite-specific IgE in feline allergic skin disease.     

Malassezia spp. overgrowth in allergic cats

A series of 18 allergic cats with multifocal Malassezia spp. overgrowth is reported: atopic dermatitis was diagnosed in 16, an adverse food reaction in another and one was euthanized 2 months after diagnosis of Malassezia overgrowth. All the cats were otherwise healthy and those tested (16 out of 18) for feline leukaemia or feline immunodeficiency virus infections were all negative. At dermatological examination, multifocal alopecia, erythema, crusting and greasy adherent brownish scales were variably distributed on all cats. Cytological examination revealed Malassezia spp. overgrowth with/without bacterial infection in facial skin (n = 11), ventral neck (n = 6), abdomen (n = 6), ear canal (n = 4), chin (n = 2), ear pinnae (n = 2), interdigital (n = 1) and claw folds skin (n = 1). Moreover, in two cats Malassezia pachydermatis was isolated in fungal cultures from lesional skin. Azoles therapy alone was prescribed in seven, azoles and antibacterial therapy in eight and azoles with both antibacterial and anti-inflammatory therapy in three of the cats. After 3-4 weeks of treatment, substantial reduction of pruritus and skin lesions was observed in all 11 cats treated with a combined therapy and in five of seven treated solely with azoles. Malassezia spp. overgrowth may represent a secondary cutaneous problem in allergic cats particularly in those presented for dermatological examination displaying greasy adherent brownish scales. The favourable response to treatment with antifungal treatments alone suggests that, as in dogs, Malassezia spp. may be partly responsible for both pruritus and cutaneous lesions in allergic cats.     

Clinical and histological evaluation of immediate and delayed flea antigen intradermal skin test and flea bite sites in normal and flea-allergic cats

Seven cats diagnosed as flea allergic by specific criteria and seven normal control cats were exposed to flea bites in a controlled manner and were given intradermal injections of 1:1000 w/v flea antigen. Subjective evaluation of gross lesions and documentation of histological changes at flea antigen intradermal skin test (IDST) and flea bite sites were performed at 15 min, 24 h and 48 h after IDST or flea exposure. Control cats did not develop an immediate gross reaction to either flea bites or the intradermal injection of flea antigen. All seven flea-allergic cats had an immediate gross reaction at the site of IDST with flea antigen; five of these cats also developed immediate gross reactions to flea bites. Three of seven flea-allergic cats developed a gross 24 h and/or 48 h delayed reaction at the flea antigen IDST sites. These three and one other cat had both an immediate and delayed gross reaction to flea bites. Histological examination of 15 min skin specimens from IDST and flea bite sites of flea-allergic cats were similar with a mild lymphocytic, histiocytic and mastocytic superficial perivascular dermatitis. Histological examination of 24 h and 48 h skin specimens from IDST and flea bite sites of flea-allergic cats showed that they were often indistinguishable. Histological features of IDST and flea bite sites of flea-allergic cats at 24 h consisted of a perivascular to diffuse predominately eosinophilic dermatitis and mural folliculitis with variable epidermal necrosis and ulceration.     

Dermatophytosis and papular eosinophilic/mastocytic dermatitis (urticaria pigmentosa-like dermatitis) in three Devon Rex cats

PRESENTING SIGNS: Three Devon Rex cats were presented with multiple erythematous papules, occasionally associated with crusting and hyperpigmentation, with a linear distribution on the head, neck, chest and abdomen. One cat also had multifocal alopecia with hyperpigmentation on the dorsum. DIAGNOSIS AND TREATMENT: Clinical and histopathological features were suggestive of papular eosinophilic/mastocytic dermatitis (urticaria pigmentosa-like dermatitis). In all cases, dermatophytosis was diagnosed: in cases 1 and 2 there was histopathological evidence of dermatophytosis, while fungal culture was positive for Microsporum canis in cases 2 and 3. In all cats, lesions disappeared following antifungal treatment. CLINICAL SIGNIFICANCE: Papular eosinophilic/mastocytic dermatitis in Devon Rex cats may represent either an atypical presentation of dermatophytosis or a clinical and histological reaction pattern to various diseases, including dermatophytosis and allergic diseases. Clinical differentiation is crucial as there are important implications regarding treatment and, in particular, the use of glucocorticoids, which are contraindicated in cases of dermatophytosis.     

Expression of RANTES mRNA in skin lesions of feline eosinophilic plaque

Abstract One of the mechanisms of eosinophil infiltration is its induction by chemoattractants such as regulated upon activation, normal T-expressed and secreted (RANTES) which is a cysteine–cysteine chemokine that mediates chemotaxis and activation of eosinophils in humans and mice. Skin lesions of feline eosinophilic plaque are characterized by a predominant infiltration of eosinophils. The mechanism(s) of eosinophilic infiltration in the skin and/or mucosa of cats is unknown. It is possible that RANTES is involved. To investigate the presence of RANTES in the skin of cats with eosinophilic plaques and nonaffected skin, we cloned and sequenced the full-length feline RANTES cDNA gene, in order to determine whether it is present in the skin of cats with eosinophilic plaques and/or if it is present in normal adjacent skin. We were able to document the the expression of RANTES mRNAs in skin with feline eosinophilic plaque as well as in normal cat skin. The full-length cDNA sequence of the RANTES gene (742 bp) contained a single open reading frame of 276 bp encoding a protein of 92 amino acids. The amino acid sequence of feline RANTES shared 67 and 74% sequence identity with that of bovine and mouse RANTES genes, respectively. RT–PCR analysis on RANTES mRNA in the skin of cats with eosinophilic plaque revealed that its expression was higher in the eosinophilic plaque skin lesions than in the normal skin. The result suggested that RANTES might play a role to induce eosinophil infiltration in feline eosinophilic plaque lesions.     

Ulcerative facial and nasal dermatitis and stomatitis in cats associated with feline herpesvirus 1

Ulcerative dermatitis of the nasal planum or haired skin of the face, associated with intranuclear inclusion bodies compatible with herpesvirus, was identified in nine cats. Clinically, lesions were ulcerative and crusted, and often persistent. A tenth cat had focal proliferative ulcerative stomatitis, also associated with intranuclear inclusion bodies. Microscopically, there was necrosis and ulceration associated with prominent eosinophilic inflammation. Intranuclear inclusion bodies were noted in all cases, within the surface or adnexal epithelium. Ultrastructural examination of skin from two cats revealed virions morphologically compatible with a herpesvirus. Polymerase chain reaction (PCR) specific for feline herpesvirus 1 on DNA extracted from fresh-frozen or formalin-fixed paraffin-embedded biopsy samples and/or consensus primer PCR with DNA sequencing performed on DNA extracted from formalin-fixed paraffin-embedded biopsy samples from seven cats revealed that the virus was indistinguishable from feline herpesvirus 1. PCR was negative in one of eight cats tested.     

Comparison of clinical history and dermatologic findings in 29 dogs with severe eosinophilic dermatitis: a retrospective analysis

The medical records and histopathological sections of 29 dogs diagnosed with a unique eosinophilic dermatitis resembling Wells' syndrome were reviewed in an attempt to elucidate the pathogenesis of this syndrome. The medical records were reviewed for information on dermatological lesion appearance, systemic signs in other organ systems, clinical analyte abnormalities, and drug therapy. Histological sections of dogs with moderate to severe eosinophilic dermatitis without folliculitis and furunculosis were reviewed and evaluated for the presence of collagen flame figures. Three categories of patients were found. Category 1 consisted of 17 dogs treated for vomiting and/or diarrhoea (often haematochezia or haematemesis) prior (mean: 4.6 days) to the onset of skin lesions. Fourteen category 1 dogs had erythematous lesions (macules, papules or plaques) that were most pronounced on the abdomen. Sixteen of the 17 dogs received multiple classes of drugs, and 59% were hypoalbuminemic. Category 2 consisted of five dogs that had skin lesions and gastrointestinal signs at presentation and four of these dogs were hypoalbuminemic. Category 3 included seven dogs without enteric illness. A positive drug score was found in six category 1 dogs and one each from categories 2 and 3. Eighteen cases had eosinophilic dermatitis without flame figures, seven cases had early flame figures and four had well-developed flame figures. These changes did not correlate with the categories of clinical presentation. More than 50% of the dogs developed eosinophilic dermatitis following treatment for severe gastrointestinal disease. The authors propose that this represents a unique syndrome that may have causal drug association.     

Eosinophilic papulocrustous dermatitis (miliary dermatitis) and eosinophilic inflammatory bowel disease in two cats

Two cats with chronic eosinophilic skin disease were investigated. The clinical investigation of the skin disease in one cat was limited and inflammatory bowel disease was diagnosed post mortem. A history of weight loss and a palpably thickened bowel in the second cat suggested concurrent gastrointestinal disease. Diagnosis of inflammatory bowel disease was confirmed on biopsy. Treatment with azathioprine and methylprednisolone acetate resolved the signs of gastrointestinal disease, the pruritus and 95% of the skin lesions. The concurrence of eosinophilic papulocrustous dermatitis and eosinophilic bowel disease raises the possibility of their being linked bv a common aetiology or pathophysiology.     

A seasonal eosinophilic dermatitis in cats

Twenty cats from Nelson with distinctive crusting and erosive dermatitis of the nasal bridge and histological lesions of eosinophilic dermatitis, often with collagenolysis, were examined in 1990 and 1991. Four of the cats also had pinnal dermatitis and five had eruptive lesions on the chin. The condition was intermittent and seasonal, occurring in summer and autumn. It is probable that the lesions were caused by hypersensitivity to insect bites, as has been demonstrated in a similar clinicopathological syndrome recently recognised in Australia.     

Patch test reactions to house dust mites in dogs with atopic dermatitis

The purpose of this study was to determine the percentage of dogs with spontaneous atopic dermatitis that show a positive patch test reaction to a commercially available 20% house dust mites mixture containing equal parts of Dermatophagoides farinae and Dermatophagoides pteronyssinus in white petrolatum. In addition, we evaluated whether skin reactions induced after the epicutaneous application of house dust mites were clinically and histologically similar to naturally developed skin lesions of dogs with atopic dermatitis. Furthermore, we investigated if the reactions induced by house dust mites were true allergic reactions by comparing them to atopic lesional skin and to patch test reactions induced by an irritant substance (sodium lauryl sulphate). White petrolatum alone and nonlesional skin sites were used as negative controls. Macroscopic and microscopic evaluations of the patch test and control sites were performed in a blinded fashion at 48 and 72 h after patch test application. Microscopic results were evaluated in a qualitative and quantitative manner. A chi‐square test for homogenicity was used for the quantitative analysis to compare the proportion of each dermal inflammatory cell type among positive histopathological tested sites. P values ≤ 0.05 were considered significant. The study included 12 healthy nonatopic dogs and 13 dogs with nonseasonal atopic dermatitis. None of the nonatopic dogs reacted to house dust mites and white petrolatum. Ten (77%) of the 13 atopic dogs reacted macroscopically and histopathologically to house dust mites. Macroscopic reactions induced by house dust mites were characterized by erythema, oedema and papules. The macroscopic reactions induced by house dust mites were identical to lesional skin in 20% of the dogs and identical to reactions induced by sodium lauryl sulphate in 40% of the dogs. Qualitative histopathological findings showed that the reactions induced by house dust mites were similar to atopic lesional skin in 80% of the dogs and were similar to sodium lauryl sulphate in 20% of the dogs. Quantitative analyses showed that the proportion of neutrophils in reactions induced by sodium lauryl sulphate was significantly higher (P < 0.05) compared to house dust mites reactions, which could be a differentiator factor between an allergic and an irritant reaction. These results showed that the epicutaneous application of house dust mites in dogs with atopic dermatitis induced histopathological lesions similar to spontaneous atopic lesions in dogs. Therefore, this study demonstrated that house dust mites penetrated the skin of dogs with atopic dermatitis and induced an inflammatory response that resembled a true allergic reaction. Funding: Small Companion Animal Grant, University of Minnesota.     

The efficacy of cyclosporine A in cats with presumed atopic dermatitis: a double blind, randomised prednisolone-controlled study

The objective of this study was to compare the efficacy of cyclosporine A (CsA) and prednisolone in feline atopic dermatitis (AD) in a randomised, controlled double blind study. Twenty-nine cats with feline AD were randomly allocated to two groups. Eleven cats were treated orally with prednisolone (1mg/kg SID) and 18 were treated with CsA (5mg/kg/day) for 4 weeks. At day 0 (D0) and D28, skin lesions were graded by means of the canine atopic dermatitis extent and severity index (CADESI). Skin biopsies and intradermal allergy tests were performed at D0 and blood samples for haematology and serum biochemistry were collected at D0 and D28. During the trial the cat owners were asked to evaluate the intensity of the pruritus once weekly on a linear analog scale and to record side effects. Based on the CADESI there was no significant difference between the two groups in the amount of remission (P=0.0562) or in the number of cats that improved by >25% (P=0.0571). The effect of CsA and prednisolone on pruritus as evaluated by the owners was not significantly different (P=0.41) between the two groups. No serious side effects were observed. The conclusion was that CsA is an effective alternative to prednisolone therapy in cats with presumed atopic dermatitis.