Feline Eosinophilic Keratoconjunctivitis: Nonsteroidal vs Corticosteroid Topical Treatment

Background: Feline eosinophilic keratoconjunctivitis is a proliferative eye lesion of chronic aspect with usually unilateral presentation that may initiate as a superficial vascularization that evolves to a proliferative, granular, irregular lesion of whitish-pink aspect. With its association with an immune-mediated response, nonsteroidal anti-inflammatories do not appear to be efficient, although few studies describe its use. This case report describes a case of a feline eosinophilic keratoconjunctivitis with its clinical evolution since the use of nonsteroidal topical anti-inflammatory drug in an undiagnosed patient and the transition to a topical corticosteroid and cure after 14 days since diagnosis. Case: An 8-year-old female cat was attended at the Veterinary Hospital of the Dom Bosco Catholic University (UCDB), with main complaint being an eye injury with at least 36 days of evolution and unresponsive to treatment (topical tobramycin 0.3% every 12 h / ketorolac trometamol 0.5%/ every 12 h and ophthalmic lubricant/every 4 h). Since the patient had free access to the street, the owners suspected of trauma-induced lesion. At physical examination, it was observed a proliferative lesion at the peri-limbal superotemporal quadrant of the right cornea with approximately 0.4 cm diameter, with color varying of pale to pink, with irregular surface and low vascularity, the adjacent conjunctiva was also affected with similar multiple nodular lesions (0.1 cm). Fluorescein test was negative as well as FIV/FeLV immunochromatography testing. Feline herpesvirus investigation was not possible. The patient was anesthetized and a lesion specimen was acquired with a cotton swab scraping and a fine needle aspiration. Cytology showed predominance of eosinophils and mast cells, with rare corneal epithelial cells, with smear background containing mast cell granules and free eosinophils. Presumptive diagnosis was eosinophilic keratoconjunctivits. After 14 days of topical corticosteroid (prednisolone acetate 1% every 8 h) the patient showed complete remission of the lesions with no relapse in 48 days. Discussion: Misdiagnosis and consequently mistreatment seems a greater prejudice than the risks associated with sample collection of keratoconjunctival proliferative lesions. Due to the lack of cytobrush or cotton swab, apparently, the reported patient was not submitted to ophthalmic cytology due to reluctance of the staff regarding fine needle aspiration of the cornea lesion. Despite a greater risk of iatrogenic trauma with needle aspiration, with eye anatomy well defined, level size and movement amplitude respected, it is unlikely that severe complications could occur. In this case, the undiagnosed patient was submitted to unnecessary 15 days of topical antibiotic and nonsteroidal anti-inflammatory, and no improvement of the clinical signs was observed. Despite non-recommended, few clinical trials as well as case descriptions are available comparing nonsteroidal and corticosteroid treatment of the disease. Once with diagnosis and beginning of topical prednisolone acetate 1% exclusively, the patient showed continuous improvement until complete remission of clinical signs after 14 days. This report reinforces the recommendation of corticosteroid therapy for feline eosinophilic keratoconjunctivitis and the absence of efficacy of nonsteroidal drugs. It also highlights the importance of diagnosis before any medical treatment is considered.