title: A retrospective study comparing histopathological and immunopathological features of nasal planum dermatitis in 20 dogs with discoid lupus erythematosus or leishmaniosis.
abstract: BACKGROUND
  In areas endemic for leishmaniosis, discoid lupus erythematosus (DLE) and canine leishmaniosis (CanL) are the most common differential diagnoses for nasal planum erosive-ulcerative dermatitis in dogs.
  
  
  OBJECTIVE
  To compare histopathological and immunopathological features of canine nasal planum erosive-ulcerative dermatitis with depigmentation due to DLE or CanL.
  
  
  METHODS
  Nasal planum biopsies from dogs with nasal planum loss of architecture, depigmentation, swelling, erosions or ulcerations due to DLE (n = 14) or CanL (n = 6).
  
  
  METHODS
  Sections of paraffin-embedded samples, stained with haematoxylin and eosin were reviewed. Samples were examined using antibodies targeting T cells (CD3), B cells (CD20), macrophages (Mac387) and class II major histocompatibility complex (MHC II). Histopathological and immunophenotypical findings were compared between DLE and CanL cases.
  
  
  RESULTS
  Lichenoid and interface dermatitis were observed in both DLE and CanL cases. A nodular-to-diffuse, superficial and/or deep dermatitis with macrophages, lymphocytes and plasma cells was present only in CanL samples. CD20-positive cells predominated over CD3- and Mac387-positive cells in the two conditions. The percentage of dermal Mac387-positive cells was higher in CanL compared to DLE samples and the difference was statistically significant (P = 0.025).
  
  
  CONCLUSIONS
  In this study, similar histopathological and immunopathological findings were observed in dogs with nasal planum lesions due to DLE or CanL. Therefore, in areas endemic for leishmaniosis, the presence of the parasite should be investigated in canine nasal planum dermatitis showing clinical and histopathological features suggestive of DLE.
authors.affiliation: Clinica Veterinaria Privata San Marco, Via Sorio 114/C, 35141, Padova, Italy.|Laboratorio d'Analisi Veterinarie San Marco, Via Sorio 114/C, 35141, Padova, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: De Lucia
authors.affiliation: Laboratorio d'Analisi Veterinarie San Marco, Via Sorio 114/C, 35141, Padova, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Mezzalira
authors.affiliation: Department de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Bardagí
authors.affiliation: Department de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
authors.forename: Dolors M
authors.initials: DM
authors.lastname: Fondevila
authors.affiliation: U.O. Qualità, Ricerca Organizzativa e Innovazione, AUSL della Romagna, Via Coriano 38, 47924, Rimini, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Fabbri
authors.affiliation: Veterinaria Cetego, Via M.C. Cetego 20, 00177, Roma, Italy.|Ambulatorio Veterinario Trastevere, Viale Glorioso 23, 00153, Roma, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fondati
mesh_terms: D000818:Animals; D003872:Dermatitis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000209:etiology / Q000276:immunology / Q000473:pathology*; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D007896:Leishmaniasis / Q000150:complications / Q000276:immunology / Q000662:veterinary*; D008179:Lupus Erythematosus, Discoid / Q000150:complications / Q000276:immunology / Q000662:veterinary*; D008297:Male; D009666:Nose / Q000473:pathology*; D012189:Retrospective Studies