Ulcerative neutrophilic dermatitis resembling human bromoderma in a dog

A dog was referred because of the presence of painful ulcers with violaceous borders and multiple dermal and subcutaneous haemorrhagic nodules on the bridge of the nose, on the dorsal aspect of the front paws, and on all four legs. Lesions had not responded to antibacterial and immunomodulatory therapy. Nine months earlier, the dog had been diagnosed with idiopathic epilepsy and treated with potassium bromide ever since. Histopathological examination of lesions revealed an interstitial neutrophilic dermatitis multifocally extending to the subcutaneous tissue. All special stains were negative for infectious agents, and due to the lack of tropism for follicular structures as well as negative bacterial and fungal cultures, a diagnosis of a sterile neutrophilic process similar to pyoderma gangrenosum was made. A cutaneous drug reaction was suspected, potassium bromide was suspended, and after 6 weeks the ulcerative lesions were completely healed. The present report describes a case of an ulcerative neutrophilic dermatitis presumed to be associated with administration of potassium bromide that resembled human bromoderma.