Atypical Cogan's Syndrome Presenting as Anterior Scleritis: Case Report

Cogan's syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis. Typical Cogan's syndrome manifests with interstitial keratitis and audiovestibular symptoms occurring within a 2-year interval, whereas atypical Cogan's syndrome involves inflammatory ocular disease without interstitial keratitis (such as scleritis, episcleritis, uveitis, or choroiditis), audiovestibular impairment, and systemic manifestations with delays longer than 2 years between different organ involvements. Atypical Cogan's syndrome usually presents with scleritis and choroiditis and is more frequently associated with systemic inflammation compared to typical forms, with approximately 70% of patients developing systemic manifestations. The diagnosis remains one of exclusion, requiring meticulous investigation to rule out infectious and other autoimmune etiologies, as no specific diagnostic criteria or biomarkers exist.

A 40-year-old White female presented with recurrent episodes of ocular inflammation and sensorineural hearing loss over a 10-year period, initially treated as isolated conditions. She was evaluated for systemic autoimmune and infectious causes, all of which were excluded through serologic and imaging studies. Anterior scleritis was confirmed on ophthalmic examination with incomplete blanching on topical phenylephrine testing. Audiometry revealed bilateral sensorineural hearing loss. A diagnosis of atypical Cogan's syndrome was made based on clinical history and exclusion of other etiologies. High-dose oral corticosteroids (prednisolone 40 mg daily) led to initial improvement. However, the patient experienced disease flares following intolerance or inadequate response to several steroid-sparing agents, including methotrexate (discontinued due to alopecia after 3 months), azathioprine (150 mg daily for 6 months), and mycophenolate mofetil (3,000 mg daily for 6 months). A subconjunctival triamcinolone injection (40 mg) was administered during a relapse, and adalimumab (40 mg subcutaneously every 2 weeks) was subsequently initiated, resulting in clinical stability with no further ocular or auditory deterioration at 12-month follow-up. This therapeutic escalation represents an evidence-based approach for refractory disease, as infliximab has been shown to be the only significant predictor of vestibulo-auditory improvement in Cogan's syndrome, with other TNF-α antagonists including adalimumab demonstrating efficacy in case reports.

Cogan's syndrome is a rare autoimmune vasculitis that can present with various ocular and auditory manifestations. While interstitial keratitis is classically described, anterior scleritis represents a less common but recognized presentation. This case underscores the importance of considering atypical Cogan's syndrome in patients with recurrent ocular inflammation and sensorineural hearing loss, whether occurring simultaneously or sequentially over extended periods. Early recognition of the unifying diagnosis and prompt escalation to biologic therapy when conventional immunosuppressants fail may prevent irreversible audiovestibular damage.