Clinical presentation, treatment and outcome in dogs with pemphigus foliaceus with and without vasculopathic lesions: an evaluation of 41 cases

Abstract

Background Concurrent vasculopathic lesions in dogs with pemphigus foliaceus (PF) have been observed anecdotally yet not reported in the literature. Any association with prognosis is unclear. Hypothesis/Objectives To compare clinical features and outcome of PF in dogs with and without vasculopathic lesions. Animals Archived, formalin‐fixed, paraffin‐embedded biopsy samples of 41 dogs with PF. Methods and materials Archived, formalin‐fixed, paraffin‐embedded biopsy samples with a histological diagnosis of PF were selected and re‐evaluated independently. Dogs were assigned to groups following histological evaluation: Group 1 (no vasculopathic lesions) and Group 2 (vasculopathic lesions present). Group 2 was subdivided into Group 2a (vasculopathic lesions without vasculitis – i.e. vasculopathy) and Group 2b (overt vasculitis). Medical records from identified cases were reviewed retrospectively for data on clinical presentation, treatment and outcome. Results Time to remission was longer in Group 2b (93.8 days) compared to Group 1 (41.8 days) (P = 0.047). Dogs in groups 2a and 2b were more likely to have systemic signs of illness at presentation (P = 0.028 and P = 0.032, respectively) compared to Group 1. Dogs in Group 2b were more likely to have adverse effects associated with treatment than dogs in Group 1 (P = 0.004). There were no significant differences in lesion type, distribution, rates of remission, recurrence or corticosteroid dosage between groups. Conclusions and clinical importance Dogs with PF and concurrent vasculitis took longer to achieve remission and were more likely to have systemic signs of illness or adverse effects associated with treatment than dogs with PF without concurrent vasculopathic lesions.

Histopathological characterisation of trunk‐dominant canine pemphigus foliaceus, and comparison with classic facial and insecticide‐triggered forms

“…The cause was not apparent, and this vessel injury was in the panniculus, distant from pustules. Vasculopathic and vasculitis lesions were reported previously in canine PF 41 . In our study, similar vasculopathic lesions of oedema, microhaemorrhage and perivascular fibrin exudation occurred relatively commonly, and were attributed to secondary inflammatory mediator injury of small vessels.…”

“…Vasculopathic and vasculitis lesions were reported previously in canine PF. 41 In our study, similar vasculopathic lesions of oedema, microhaemorrhage and perivascular fibrin exudation occurred relatively commonly, and were attributed to secondary inflammatory mediator injury of small vessels. These lesions were superficial in the dermis and below pustules, consistent with secondary changes to pustule reaction-related mediators.…”

“…This finding also is consistent with the lack of vascular‐based clinical skin lesions reported in canine PF. In the previous study, 41 the morphological criteria for vasculitis appeared to include milder changes, some that overlapped with secondary vasculopathic reactive changes, and may explain why more cases of vasculitis were reported.…”

Dermatological Problems of Brachycephalic Dogs

“…There is variable pruritus and secondary bacterial and Malassezia infections. In severe cases, fever, lethargy, anorexia, and lymphadenopathy are also present [ 85 , 181 ]. Cytology of intact pustules reveals neutrophils, eosinophils, and acantholytic cells in the absence of bacteria.…”

“…A definitive diagnosis is attained via multiple skin biopsies and histopathology [ 85 ]. Treatment typically includes topical and systemic antimicrobials as well as immunosuppressive drugs such as glucocorticoids, cyclosporine, azathioprine, chlorambucil, mycophenolate mofetil, and recently, oclacitinib [ 14 , 85 , 181 ]. Potential triggers should be eliminated.…”