Spongiotic vesicular dermatitis as a cutaneous reaction pattern in seven horses

Over a 6-year period seven adult horses of different breeds and genders developed multifocal, exudative, oozing dermatitis characterized histologically by epidermal spongiotic vesicles and perivascular eosinophilic, neutrophilic and mixed mononuclear inflammation. Three horses were pruritic. Systemic disease was not noted. Two horses had a history of recurrent urticaria (hives) and one horse had nodules or welt-type lesions that progressed to exudative, oozing lesions. Interepithelial immunoglobulin (Ig)G was detected by avidin-biotin complex-peroxidase staining, but the pattern of staining was more consistent with epithelial oedema than specific IgG deposition associated with pemphigus. The exudative oozing lesions developed under circumstances suggesting that dermal oedema progressed to intracellular and intercellular epidermal oedema, which in turn progressed to the spongiotic vesicular epidermal lesions.     

Pemphigus Foliaceus in a Horse

Abstract— A 3-year-old gelding was presented with a generalized chronic dermatitis characterized by erosions, ulcerations, crusting, scaling and widespread alopecia. The diagnosis of pemphigus foliaceus was based on history, clinical signs, histological lesions and immunohistological test results. Typical dermatohistopathological findings comprised intraepidermal acantholysis and cleft formation in both epidermis and hair follicle epithelium. Additionally, blisters and erosive lesions were found in the epithelia of various mucocutaneous junctions, the distal oesophagus and the oesophageal zone of the stomach. In formalin-fixed and paraffin-embedded tissues an immunoperoxidase technique was established to demonstrate deposits of the immunoglobulins G and M and the complement component C3 providing the opportunity to compare histological and immunohistological findings. Résumé— Un cheval hongre de 3 ans a été présenté avec une dermite chronique caractérisée par des érosions, des ulcères, des croutes, des squames et une alopécie très étendue. Le diagnostic de pemphigus foliacé reposait sur l'anamnèse, l'examen clinique et les résultats des examens histopathologiques et immunopathologiques. Les lésions histologiques typiques comprenaient des acantholyses intraépldermiques et la formation de fissures tant au niveau de lépiderme que des follicules pileux. En outre, des bulks et des érosions ont été retrouvées au niveau de différentes junctions cutanéomuqueuses et de la partie distalé de l'oesophage. Une technique d'immunopéroxydase sur tissus fixés au formol et en paraffine a été utilisée pour mettre en évidence des dépôts d'immunoglobulines G et M et de C3, permettant de comparer les observations histologiques et immunopathologiques. Zusammenfassung— Ein dreijähriger Wallach wurde mit einer generalisierten chronischen Dermatitis vorgestellt, die durch Erosionen, Ulzerationen, Krusten, Schuppen und ausgedehnte Alopezie gekennzeichnet war. Die Diagnose Pemphigus foliaceus stützte sich auf den Vorbericht, die klinischen Symptome, die histologischen Veränderungen und die Ergebnisse des immunohistologischen Tests. Die typischen histopathologischen Befunde umfaßten intraepidermale Akantholyse und Spaltbildung sowohl in der Epidermis wie im Epithel des Haarfollikels. Zusätzlich wurden Blasen und erosive Veränderungen in den Epithelien verschiedener mukokutaner übergänge, im distalen ösophagus und in der ösophagealen Zone des Magens gefunden. An formalinfixiertem und in Paraffin eingebettetem Gewebe wurde eine Immunoperoxidasetechnik durchgeführt, um die Ablagerungen von Immunglobulinen G und M und der Komplementkomponente C3 zu zeigen, wodurch die Gelegenheit bestand, histologische und immunohistologische Befunde zu vergleichen. Resumen Un caballo de tres anos fue presentado con una dermatitis crónica de tipo generalizado presentando erosiones, ulceraciones, costras y escamas epidérmicas, además de una alopecia generalizada. Una diagnosis de pémfigo foliáceo se basó en la historia y cuadro clínico, lesiones histológicas y resultados de tests inmunohistológicos. Los hallazgos dermato-histopatológicos típicos comprendieron acantolisis intraepidermica y la formación de indentaciones epidérmicas en ambos, epidermis y epitelio del folículo piloso. También se observó la presencia de vesículas y lesiones erosivas en el epitelio de las uniones mucocutaneas, asi como en áreas distales del esófago, y en zonas esofágicas del estómago. Después de la fijación en formol y sumersión en parafina de los tejidos, se utilizo la técnica de inmunoperoxidasa para la demonstratión de depósitos de inmunoglobulinas G y M, y el complemento C3, que proporcionó la oportunidad de comparar los hallazgos inmuno e histológicos.     

Modulation of the response of rainbow trout (Oncorhynchus mykiss Walbaum) to confinement, by an ectoparasitic (Argulus foliaceus L.) infestation and cortisol feeding

The effects of a 21 day infestation with the ectoparasite Argulus foliaceus on the response of rainbow trout Oncorhynchus mykiss to an acute stressor (confinement) were investigated. Fish were divided into a control and two parasitized groups, with one parasitized group having received cortisol feeding 72 and 24 h before infection. Prior to confinement only control fish showed a significant increase in body mass and condition factor. Following 4 h confinement, plasma glucose levels in the normal- fed/infested group were significantly higher than in the controls, while the cortisol-fed/infested group had significantly lower plasma levels of adrenocorticotropic hormone (ACTH) and glucose. Both infested groups, but not controls, had higher plasma ACTH and cortisol levels 48 h after confinement when compared with their pre-confinement levels. Stressor-induced immunomodulation was more evident in the parasitized fish after confinement, as was concluded from decreased lysozyme activity, alternative complement activity and oxygen radical production either immediately after, or 48 h post 4 h confinement. Circulating lymphocyte numbers were significantly reduced in the control and normal-fed/infested fish. Results indicate that low ectoparasitic infestations can, for a prolonged period, lead to a stress experience with effects that impair the response to subsequent stressors. Such effects may be further confounded by a previous elevation of plasma cortisol levels.     

Cutaneous paraneoplastic syndromes in dogs and cats: a review of the literature

Cutaneous paraneoplastic syndromes are a group of noncancerous dermatoses associated with internal malignancy. Their recognition can facilitate detection and timely treatment of underlying cancer. More than 30 such disorders have been identified in the human scientific literature, whereas only a few are described in veterinary medicine. This may reflect a lower incidence in animals than in people or may be the result of failure to recognize an association between certain skin lesions and neoplasia. Establishing a relationship between a cutaneous disorder and neoplasia can be difficult unless the skin lesions are rare and almost always associated with a particular tumour type, as is the case for most recognized veterinary paraneoplastic dermatoses. Among these are feline paraneoplastic alopecia, feline thymoma-associated exfoliative dermatitis, nodular dermatofibrosis, feminization syndrome associated with testicular tumours, superficial necrolytic dermatitis and paraneoplastic pemphigus. The aetiology of most cutaneous paraneoplastic syndromes has remained elusive in both people and animals.     

Feline pemphigus foliaceus: a retrospective analysis of 57 cases

Fifty-seven cases of feline pemphigus foliaceus were identified from biopsy specimens submitted to University of Pennsylvania School of Veterinary Medicine's Laboratory of Pathology and Toxicology by veterinary dermatologists from 1991 to 2002. Age at onset ranged from less than 1 year to 17 years; median 5 years. Eighty per cent of cats were reported to have been pruritic. At the time of biopsy, the distribution of lesions varied, but included some combination of face/head, paws, dorsum or ventrum and consisted of crusts, erosions, scale and alopecia. The histological features of 208 biopsy specimens were reviewed and included the following. Acantholytic cells were found in large numbers in both intact and degenerating pustules in most cases. Mast cells were found in the dermal infiltrate more often than reported previously. Seventeen cases were receiving corticosteroids at the time of biopsy; reducing the percentage of diagnostic biopsies per case. Forty-four cases were followed for 1-54 months (median 9 months). Triamcinolone was more successful at inducing remission without significant adverse effects than prednisone or prednisone in combination with chlorambucil. Only 4/44 cats died from their disease or therapy during the study period.     

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).     

Pemphigus foliaceus in the horse: a retrospective study of 20 cases

Twenty horses with pemphigus foliaceus were seen over a period of 15 years in a veterinary medical teaching hospital. Breeds seen were seven quarterhorses, five thoroughbreds, three cross-bred horses, two Arabians and one of each of the following: standardbred, Tennessee walker and warmblood. There was no breed, age or sex predisposition. Nine were mares, ten were geldings and one was a stallion. Ages ranged from 2.5 months to 25 years, with a mean of 8.6 years. Sixteen (80%) of the pemphigus foliaceus horses first exhibited signs between September and February. There was a statistically significant more common occurrence of pemphigus foliaceus during those months. Signs in the four other horses were first noted in March, May or June. Three of those horses were < 13 months of age. Oedema (14/20) and crusts (13/20) were the most common lesions. Pain was present in 9/20 horses, pruritus in 7/20 and pyrexia in 7/20. Follow-up was available for 13 horses. Five of these horses were euthanased. In three horses the reason for euthanasia was laminitis secondary to treatment. Four horses remained lesion-free after medication was discontinued. Two horses required maintenance medication and are doing well at the time of writing.     

Comparison of three monoclonal and three polyclonal antibodies in the immunohistochemical diagnosis of canine autoimmune skin diseases

The aim of this study was to evaluate the utility of three monoclonal antibodies (mAbs), and two anticanine IgG and one anticanine IgM polyclonal antibodies (pAbs) for the immunohistochemical diagnosis of canine autoimmune skin diseases. Skin biopsies from 11 cases of pemphigus (7 foliaceus, 3 vulgaris and 1 erythematosus), 12 cases of discoid lupus erythematosus (DLE) and 12 cases of chronic hyperplasic dermatitis were used. The CA4E7 mAb (IgG1 + IgG2) showed similar sensitivity, but higher specificity and lower background than the two anti-IgG pAbs for the immunohistochemical diagnosis of pemphigus and DLE. The CA4F1 mAb (IgG2) and CA3H1 mAb (IgG2) showed moderate and low interepithelial reactivity, respectively, in autoimmune skin diseases, but strong staining of the cytoplasm of plasma cells of the inflammatory infiltrates. These results suggest that the CA4E7 mAb may be valuable in the immunohistochemical diagnosis of such disorders.     

Detection of circulating autoantibodies using living keratinocyte staining on MCA-B1 method in dogs with pemphigus foliaceus

In this study, we compared the sensitivity and specificity of three immunofluorescence techniques used to detect circulating autoantibodies in dogs with pemphigus foliaceus (PF); living keratinocyte staining on a canine keratinocyte cell line, MCA-B1, indirect immunofluorescence (IIF) on canine lip and IIF on bovine esophagus. Sera from canine PF cases were positive in four out of 27 dogs (14.8%) using living keratinocyte staining on MCA-B1 cells method, and five (18.5%) and eight sera (29.6%) using IIF on canine lip and bovine esophagus methods, respectively. By contrast, none of the 31 sera from dogs with non-pemphigus dermatoses reacted with MCA-B1 cells, whereas two (6.5%) as well as five sera (16.1%) obtained from those dogs showed positive reactivity with IIF on canine lip and bovine esophagus, respectively. Our results suggest that, although it exhibits the least sensitivity, the positive reactivity obtained by living keratinocyte staining on MCA-B1 cells can support the diagnosis of canine PF.     

Putative drug-related pemphigus foliaceus in four dogs

Four dogs developed cutaneous lesions following the administration of various antibiotics. Histopathology of the lesions was compatible with pemphigus foliaceus, although apoptotic cells suggestive of erythema multiforme were seen in two cases. In two dogs the lesions resolved after 7.5-8.5 months of immune-suppressive treatment. No recurrence was seen during the follow-up period (3 and 4.5 years). The lesions in the other two dogs resolved within 3 weeks to 3 months following discontinuation of the antibiotic. No recurrence of clinical signs occurred during the follow-up period (1 and 4 years, respectively).