Interface diseases
Case No. 5; Slide No. B13/8956/2
Histological findings Severe hydropic vacuolation of epidermal and follicular basal cells/ interface dermatitis Multifocally apoptotic keratinocytes in the epidermal and follicular basal/suprabasal layer Multifocal detachment of epidermis from dermis at margins of biopsies Moderate to severe subepidermal bandlike infiltrate with exocytosis of inflammatory cells into the lower half of the epidermis composed of lymphocytes, plasma cells, mast cells and few neutrophils Multifocal ulceration Multifocal supepidermal fibrosis Moderate regular hyperplasia of epidermis
Morphological diagnoses Severe diffuse interface dermatitis with apoptotic cells in the basal/suprabasal layer of the epidermis and multifocal subepidermal vesiculation and multifocal ulceration Moderate diffuse interface mural infundibular folliculitis
Case No. 7; Slide No. B13/8956/2 Border Collie Mukas 2 years, male Since several months crusts around the eyes and in the neck Progression to mucocutaneous junctions of mouth Now in inguinal region and on thorax coalescing ulcers with well-demarcated serpiginous borders Lesions also present on legs
J. Dawidowicz
J. Dawidowicz
Name of the disease Vesicular cutaneous lupus erythematosus Differential diagnoses Other forms of lupus erythematosus Dermatomyositis Erythema multiforme Lupus-like drug reactions (Subepidermal vesicular diseases)
Typical clinical features Shetland sheep dogs and collies, their crossbreeds or related breeds Middle aged and older dogs Figurate/serpiginous erythema vesicles and bullae coalescing ulcers Often starts on groin and axillae May involve mucocutaneous junctions Occurs mostly in summer
Pathogenesis Unclear Genetic predisposition Variant of CLE Lymphocyte-mediated cytotoxicity targeting the basal cell layer Direct immunofluorescence reveals regions of IgG deposition at the basal membrane zone but no evidence of circulating autoantibodies against dermal antigens
Case No. 6; Slide No. 152
Histological findings Regular laminar orthokeratotic hyperkeratosis forming large compact squames Epidermal hyperplasia, diffuse, moderate Lymphocytic exocytosis Fine subepidermal band-like infiltration of lymphocytes and plasma cells Mild vacuolar degeneration of basal cells Scattered apoptotic cells in all epidermal layers Follicular infundibula also affected
Morphological diagnosis Orthokeratotic, lamellar, exfoliative hyperkeratosis, severe, diffuse Interface dermatitis, mild, multifocal Mural interface folliculitis, moderate, multifocal with lymphocytic sebadenitis
Case No. 9; Slide No. 152 Domestic Shorthair 3 years, male-castrated Generalized alopecia and marked scaling Fever, inappetence and lethargy Since 10 days strong pruritus Skin in alopecic areas is are erythematous and painful
Silvia Rüfenacht, dermavet
Scales, erythema and crusts on ventral abdomen Silvia Rüfenacht, dermavet Hyperkeratosis and scales on footpads
Sven Rottenberg, Universität Bern
Diagnosis Name the disease Exfoliative dermatitis (feline thymomaassociated exfoliative dermatitis) Differential diagnoses Erythema multiforme Graft-versus-host disease
Clinical features Middle-aged to older cats Coughing, dyspnea, anorexia and weight loss Lesions start typically on the head, pinna and neck and then generalize Marked scaling and flaking (scales become larger in later stages of the disease) Erythema, thickened skin, crusts and ulcerations Alopecia may predominate Brown keratosebaceous debris periocular, perioral, interdigital, in the external ears and claw folds Secondary pyoderma or Malassezia dermatitis
Paraneoplastic disease in the cat Thymoma exfoliative dermatitis Remission is reported after surgical removal of the tumor Suspected pathogenesis: The diseased thymus activates autoreactive cytotoxic T cells that act on epithelial cells similar to graft-versus-host disease However, often no tumor found! Pancreas carcinoma dermatitis with shiny skin (paraneoplastic alopecia)
Verena Affolter, University of Calfornia, Davis
Nonthymoma-associated exfoliative dermatitis Nonthymoma-associated exfoliative dermatitis in cats is clinically and histopathologically indistinguishable from thymoma-associated cases Most cases benefit from immunosuppressive therapy immunopathological response to an undefined trigger is suspected Linek et al., Vet Dermatol 2015; 26:40-e13