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

## TL;DR

A diabetic cat with severe facial skin inflammation was successfully treated with oclacitinib and later required surgery to fix eyelid fusion.

## Contribution

Demonstrates successful off-label use of oclacitinib in treating a rare feline skin condition complicated by diabetes.

## Key findings

- Oclacitinib effectively treated eosinophilic furunculosis and vasculitis in a diabetic cat without worsening blood sugar.
- Eyelid fusion from skin healing was corrected with surgery to restore normal blinking.
- Histopathology confirmed the presence of eosinophilic furunculosis and vasculitis in the cat.

## Abstract

A 10-year-old male British Shorthair cat with diabetes mellitus was presented at a veterinary practice after suddenly developing swelling, redness, hair loss, and sores on one side of his face, especially around the eye. The vet first considered several possible causes, including an injury, parasites, infections (like cat flu), insect bites and allergic skin conditions. A skin sample showed the cat had a serious inflammation of the hair follicles, with a type of immune cell called eosinophils involved, as well as inflammation of the blood vessels. The vet first tried a steroid cream, which helped the skin but caused the cat’s blood sugar to rise—a problem for diabetic animals. Because of this, other strong anti-inflammatory medicines like steroid pills or ciclosporin were not good options. Instead, with the owner’s permission, the vet tried a different drug called oclacitinib (not usually used in cats). It worked very well, and the cat’s skin cleared up quickly, with no return of the problem for over a year. Later on, the cat needed surgery to fix his eyelids, which had stuck together as the skin healed, so he could blink normally again.

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.