Veterinary dermatology最新文献

Background: Mycophenolate is an immunomodulating agent successfully used for the treatment of moderate-to-severe atopic dermatitis (AD) in people. Mycophenolate is an effective steroid-sparing treatment option for use in dogs with inflammatory skin diseases.

Objective: To evaluate whether once-daily modified-release mycophenolate (OKV-1001) is safe and effective for treating moderate-to-severe canine AD.

Animals: Client-owned atopic dogs (n = 9) were enrolled.

Materials and methods: In an open-label multicentre pilot study, OKV-1001 (30 mg/kg every 24 h) was given orally for ≤84 days. Concomitant tapering doses of glucocorticoids were administered up to Day (D)28. Clinicians assessed Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) on D0, D14, D28, D56 and D84. Body weight and clinical pathological parameters were measured at baseline and at the end of the study.

Results: Treatment with OKV-1001 combined with glucocorticoids significantly reduced the severity of AD within two weeks in seven of nine (77.8%) dogs. The mean percentage change from baseline in the CADESI-04 score was 29% (p = 0.009) at D14 (n = 9), 39% (p = 0.008) at D28 (n = 9) and 49% (p = 0.03) at D56 (n = 7) at which point glucocorticoids had been withdrawn. In two dogs the improvement in CADESI-04 was 62% and 23% (respectively) on D84. No significant adverse events including clinical pathological findings were reported.

Conclusions and clinical relevance: Modified-release mycophenolate (OKV-1001) may represent a promising alternative treatment option for dogs with moderate-to-severe AD. The safety and efficacy profile of OKV-1001 will need to be established in larger, placebo-controlled clinical trials.

Background: Potential contagion and zoonotic risk make rapid diagnosis of dermatophytosis important amongst companion animals.

Hypothesis/objectives: To compare the adhesive tape impression (ATI), trichogram, Wood's lamp (WL) examination and fungal culture for diagnosis of dermatophytosis, and the ATI and trichogram for ease of use.

Animals: Five dogs and 15 cats with consistent lesions, history and at least two positive dermatophyte test results.

Materials and methods: After WL examination, one representative lesion per patient was sampled for ATI, trichogram and fungal culture. Microscopic detection of fungal elements on ATI and trichogram were objectively and subjectively compared. The ability of all tests to correctly detect dermatophytosis, and the ability of ATI and trichogram to detect fungal elements in >20 high-powered fields (HPF) were compared using Fisher's exact tests.

Results: ATI, trichogram, fungal culture and WL were positive in 100% (20 of 20), 90% (18 of 20), 95% (19 of 20) and 65% (13 of 20) of patients, respectively, with a significant difference between WL and ATI (p = 0.0499). Fungal culture revealed Microsporum. canis (n = 16), Nannizzia gypsea (n = 1), Trichophyton mentagrophytes (n = 1) and T. rubrum (n = 1). Fungal elements were detected in >20 HPF more frequently with ATI (18 of 20) than trichogram (11 of 20) (p = 0.017), and detection required careful scanning to distinguish from background debris more often with trichogram. Fungal elements were located with neutrophil clusters and keratinocyte rafts in addition to abnormal hair fragments more frequently on ATI.

Conclusions and clinical relevance: ATI had the highest ability to correctly diagnose dermatophytosis, and increased ease of detecting fungal elements compared to trichogram.

Background: In humans, food allergies (FAs) are divided into those with immunoglobulin (Ig) E-mediated (immediate FA), cell-mediated (delayed FA) or both mechanisms (mixed FA). In dogs, lymphocyte stimulation tests have the highest concordance with oral food challenges (OFCs).

Objectives: To report the evaluation of a lymphocyte proliferation test (LPT) in dogs with FA and delayed reactions (≥6 h) after OFC.

Animals: Thirty-five healthy and 28 dogs with delayed FA.

Materials and methods: Peripheral blood mononuclear cells (PBMCs) were isolated and automatically counted before and after a 5-day culture with food allergens. Stimulation indices (SIs) were then calculated. Food allergen-specific IgE was quantified using the Pet Allergy Xplorer (PAX).

Results: None of the 10 healthy laboratory beagles and 25 healthy pet dogs had an SI greater than the 3.0 cut-off, indicating a specificity of 100%. All 28 dogs with delayed FA had at least one positive stimulation to a food item that induced delayed flares after OFC; the sensitivity of this LPT for the identification of delayed canine FA was 100%. The LPT correctly identified 57 of 68 food items causing delayed flares after OFC (84%). The PAX was negative for food-specific IgE in 18 of the 28 dogs (64%), as expected for delayed FA. In three dogs (11%), PAX results overlapped with those of the LPT, suggesting a mixed FA.

Conclusions and clinical relevance: Food allergies with delayed reactions after OFC-those suspected of having a cell-mediated mechanism-seemed to be the most common type of FA in the studied dogs. The LPT was helpful in identifying such cases.

Background: Epicutaneously house dust mite-sensitised (HDM-S) healthy dogs are commonly used as canine atopic dermatitis (cAD) models; however, the exact mechanisms of HDM-induced AD immune activation in HDM-S and HDM-nonsensitised (NS) dogs remain unclear.

Objectives: To characterise the inflammatory and pruritogenic transcriptome of acute epicutaneous HDM-induced skin lesions at 6 h and 24 h in HDM-NS and HDM-S dogs; untreated skin at 0 h from each dog served as control.

Animals: Six HDM-S and six HDM-NS laboratory beagles.

Materials and methods: Processed expression data from GEO deposited by Schamber et al. (G3 (Bethesda), 2014, 4 and 1787) (GSE58442) were downloaded and analysed using R and the Bioconductor package. Significance analysis was performed with the limma package; genes with false discovery rate <0.05 and fold-change ≤/≥1.5 were considered significantly differentially expressed (DEGs).

Results: A 2D principal component analysis revealed no clear separation between HDM-NS and HDM-S dogs at 6 h and 24 h time points. HDM-induced skin lesions in sensitised and nonsensitised dogs at the 24 h time point showed significant upregulation of T helper cell (Th)2 genes (interleukin [IL]-4R, IL-5, IL-13, CCL13 and CCL17), as well as proinflammatory- (LTB, IL-1A and IL-18), Th1- (CXCL10, OASL and MX-1) and Th17-related markers (IL-17B, IL-17F, CCL19 and CCL20). The key Th22-related maker, IL-22, was upregulated only in the HDM-S group at the 24 h time point. Both groups at 24 h featured significant upregulation of several noncytokine pruritogens, such as trypsin, chymase, cathepsin S, periostin and neuromedin B.

Conclusions and clinical relevance: Taken together, we establish that epicutaneous HDM patch application induces immune changes in HDM-NS dogs with Th2 dominance and activates several itch-promoting pathways.

Uveodermatological syndrome and alopecia areata are autoimmune disorders causing ocular and dermatological inflammation and alopecia, respectively, in dogs. This is the first report to document concurrent development of the two diseases in a dog, as has been reported in human patients. Clinical presentation and histopathological diagnosis, treatment and clinical follow-up are described.

Background: The identification of the activation of the mammalian target of rapamycin (mTOR) signalling pathway as a frequent molecular event in canine cutaneous papillomas (CPs) has provided the rational foundation to explore novel molecular-targeted therapies. Recent evidence indicates that metformin reduces the size of CPs in mice by inhibiting the mTOR signalling pathway. These effects require the expression of the organic cation transporter 3 (OCT3/SLC22A3), a well-known metformin uptake transporter.

Hypothesis/objectives: The aim of the present study was to characterise the expression pattern of the metformin uptake transporter OCT3 in canine samples of CP that have shown activation of the mTOR signalling pathway in order to predict if this hyperplastic epidermal lesion is potentially sensitive to metformin.

Methods: The expression of OCT3 was evaluated by immunohistochemical investigation in sections of a previously constructed tissue microarray containing 28 samples of canine CP and compared with that previously evaluated for the mTOR activation marker pS6.

Results: OCT3 was highly expressed in the membrane and cytoplasm of the basal and suprabasal epidermal cells in all samples of canine CP. This OCT3 expression was localised at similar epidermal compartments to those observed for pS6.

Conclusions and clinical relevance: These results show that canine CPs exhibit the expression of surrogate markers that suggest sensitivity to metformin, such as upregulated OCT3 and pS6 expression. Taken together, these findings provide the rationale for the early assessment of the use of metformin as a mechanism-based therapeutic approach for treating canine patients with persistent or multiple CPs.

Background: Canine atopic dermatitis (cAD) is a hereditary, generally pruritic and predominantly T-cell-driven inflammatory skin disease, involving an interplay between skin barrier abnormalities, allergen sensitisation and microbial dysbiosis. The individual immunological response is predominantly against environmental allergens, including mite antigens; mould spores; and pollen from grasses, trees and weeds. Airborne pollens show fluctuating patterns during the year.

Objective: The aim of this prospective study was to evaluate the influence of local pollen concentrations and weather conditions on the clinical signs of atopic dogs, and to investigate any possible correlations with the results of intradermal testing (IDT).

Materials and methods: Thirty-seven privately owned atopic dogs in Bavaria were surveyed from 1 April to 30 November 2021. Owners were asked to record pruritus using a validated Visual Analog Scale (PVAS) score and the weekly medication of their dog. Furthermore, weather data, including pollen count, rainfall, relative humidity, hours of sunshine and temperature from the dog's location were collected daily.

Results: Of the evaluated parameters, only humidity and medication scores correlated positively with the PVAS scores of the atopic dogs. There was no correlation between specific pollen counts and PVAS scores of dogs with positive IDT reactions to that pollen.

Conclusion and clinical relevance: The outcome of this study highlights the importance of a careful interpretation of positive IDT results in dogs with cAD and questions the validity of airborne pollen trap methodology in representing pollen exposure for dogs at ground level.

This report describes a multicentric intermediate-size B-cell lymphoma with epitheliotropism in a Freiberger mare affecting multiple mucous membranes, skin and internal organs. The clonal neoplastic B-cell population was accompanied by numerous reactive polyclonal small T cells. Differential diagnoses for these unusual findings are discussed.

The authors describe a case of presumptive feline subcutaneous fat sclerosis, a condition reported only once previously (in 1987) and diagnosed with postmortem examination. We describe radiographic, computed tomography scan and histopathological findings, and partial response to oral methylprednisolone and Vitamin E.

Background: Cytological detection of acantholytic keratinocytes (acantholytic cells [AC]) helps to identify canine pemphigus foliaceus (cPF) yet AC also occurs in superficial pyoderma (SP), the main differential diagnosis.

Hypothesis/objectives: To compare selected cytomorphological features of cPF and SP and to establish cytological diagnostic criteria that could differentiate cPF from SP.

Animals: 40 and 51 client-owned dogs with PF and SP, respectively.

Materials and methods: Impression smears from cPF (64), impetigo (40) and exfoliative superficial pyoderma (ESP) (17) samples were stained with Romanowsky stain, randomised, blinded and evaluated by two investigators independently. The entire sample was screened (×500 or ×1000 magnification) for round (AC1), boat (AC2) and raft AC, eosinophils and bacteria. Interobserver agreements were calculated.

Results: The average number of the 10 highest ×500 fields for AC1 and AC2 was significantly higher in PF than SP (p < 0.0001; Kruskal-Wallis test). Rafts and eosinophils were more common in PF than SP (p < 0.0001; chi-square test), while bacteria were rare in PF (5%; p < 0.0001; chi-square test). Observations between the experienced and novice investigators were highly correlated. An ROC analysis identified five AC1/×500-magnification field as a suitable cut-off value for predicting PF diagnosis. This cut-off value was tested by two additional investigators, who identified sensitivity of 84%-100%, specificity of 95%-97% and accuracy of 95%-96% for the diagnosis of cPF.

Conclusions and clinical relevance: Criterion-based impression smear cytological evaluation can provide strong evidence to support the clinical diagnosis. Acantholytic cell morphology varies in cPF and SP, and experience can improve accuracy in cytological differentiation.