A case of cutaneous sterile pyogranuloma/granuloma syndrome in a Standard Schnauzer

Abstract

Canine cutaneous sterile pyogranuloma/granuloma syndrome (SPGS) is an uncommon skin disease in dogs and cats. Clinical manifestations are skin lesions such as papules, nodules and plaques; however, nodules are the most commonly described lesions in the course of cutaneous sterile pyogranuloma/granuloma syndrome. These lesions can be single or multiple, diffuse or limited to a small area. The affected area can become alopecic. In some cases ulcerations and secondary bacterial infections may occur. The characteristic nodules are firm, well demarcated from the surrounding tissue and no pruritic with varying size between a few millimeters to a few centimeters. Histiocytic nature of the inflammatory infiltrate, the absence of the pathogen and a good response to glucocorticoid therapy suggest an autoimmune nature of the disease; however, etiology and pathogenesis remain unknown for sure. When response to steroid therapy is unsatisfactory, niacinamide, tetracycline and azathioprine are used or surgical removals of the lesions are applied. In the reported case, skin lesions were successfully treated for 6 months with prednisolone. Cutaneous sterile pyogranuloma/granuloma syndrome was diagnosed by excluding other disorders and by histopathology which revealed dermatitis with inflammatory infiltrate that was characterized by moderate histiocytic and neutrophilic along with sparse lymphocytes and plasma cells. Morever no pathogen was found in PAS staining.