Contribution of oral triamcinolone to treating proliferative and necrotising otitis externa in a 14-year-old Persian cat

Abstract

Case summaryA 14-year-old female spayed cat was referred for recurrent otitis externa and unusual proliferative lesions in both ear canals. The affected pinnae and external ear canals were covered with large reddish-to-dark-brown verrucous and necrotic tissue. Friable material and exudates occluded both ear canals. Proliferative lesions developed in both ears 2–3 weeks before referral. The histopathological diagnosis from two biopsies obtained from the friable materials with endoscopic biopsy forceps was proliferative and necrotising otitis externa (PNOE). Treatment was initiated with once-daily application of a potent topical glucocorticoid (mometasone furoate) to both ears. Although the auricle and vertical ear canals responded well, no improvement was seen in the horizontal part of the ear canal after 9 weeks. Therefore, oral triamcinolone (0.9 mg/kg q24h) was added for 1 week, and was then tapered (q48h) for 3 weeks. Most lesions resolved, and after a further 2 weeks of prednisolone (2 mg/kg q48h) there was complete resolution. No recurrence was observed during a 2 year follow-up period.Relevance and novel informationPNOE commonly occurs in kittens, but it can develop in older cats. To our knowledge, the PNOE in this case is the oldest age of onset reported. This condition is rare and was only described recently, and therapeutic options appear limited. According to previously published reports, steroid therapy is ineffective, and tacrolimus is the only treatment known to achieve resolution. However, oral and topical glucocorticoids were beneficial in this case.

Case Report: Clinical Remission in a Cat With Severe Bilateral Eosinophilic Keratitis Receiving Combined Immunosuppressive Therapy (Triamcinolone Acetonide and Tacrolimus)

“…Similar to other reports of cats receiving triamcinolone acetonide for EK or other conditions (13,19), our patient did not experience notable adverse effects from systemic corticotherapy. However, this observation should be verified in future prospective studies that include systemic workup and diagnostic testing.…”

Chronic Otitis in Cats: Clinical management of primary, predisposing and perpetuating factors

“…The most common therapies reported in the literature are topical tacrolimus and topical and systemic glucocorticoids. 28,[56][57][58]60 One of the authors (CC) has successfully treated a few severely affected young adult cats with systemic ciclosporin (Figure 3b). The clinician should evaluate for secondary infection and address it if present.…”

Extra‐auricular lesions of proliferative and necrotizing otitis externa in three kittens

“…1,3,7,8 However, some cases have been controlled by topical and systemic glucocorticoids. 2 Ciclosporin was added to topical tacrolimus in Case 1 as lesions were generalised.…”

“…The condition was first described in kittens, yet adult cats can be affected. 1,2 The pathogenesis of this condition is still unknown; however, an immunemediated disorder involving keratinocyte apoptosis by epidermal-infiltrating T cells is strongly suspected. 3 PNOE lesions are classically symmetrical and affect the base of the pinna, the opening of the ear and the vertical ear canal.…”