Oclacitinib Treatment and Surgical Management in a Case of Periocular Eosinophilic Furunculosis and Vasculitis with Secondary Eyelid Fusion in a Diabetic Cat.

A 10-year-old male neutered British Shorthair cat with diabetes mellitus presented with an acute onset of unilateral swelling, erythema, alopecia and coalescing ulcerations of the face and periocular skin. Initial clinical differential diagnoses were trauma, infections (including feline respiratory viruses), arthropod bites, and eosinophilic dermatoses such as eosinophilic granuloma complex, mosquito-bite hypersensitivity and cutaneous adverse drug reaction. Histopathology revealed fulminant furunculosis with abundant eosinophils and vasculitis. Initial topical glucocorticoid treatment partially improved the clinical signs but severely raised serum glucose levels. As a result, systemic glucocorticoids and ciclosporin were not considered optimal treatments, and the off-label and short-term use of oclacitinib was chosen with the owner's informed consent. This treatment induced fast remission of clinical signs with no recurrence for 17 months. Secondary fusion of the eyelids caused by cicatrization was surgically reconstructed to restore full function.