Anti-neutrophil cytoplasmic antibody (ANCA)-associated scleritis: A diagnostic challenge and outcome

This report aims to present the clinical challenge in managing a case of anterior scleritis associated with anti-neutrophil cytoplasmic antibody (ANCA), which was masquerading as recurrent conjunctivitis and the lines of management and disease course. A 68-year-old Malaysian male presented with bilateral blurring of vision associated with pain and redness for one-week duration. He had prior episodes of eye redness and discomfort, which was temporarily relieved with a course of corticosteroid eye drops, on presumptive diagnosis of conjunctivitis. Visual acuity was 6/18 bilaterally. Anterior segment examination showed diffuse conjunctival and episcleral injection which was tender on palpation. There was no posterior segment involvement in both eyes. Patient was tested positive for ANCA and proteinase 3 (PR3). Urinalysis showed proteinuria and hematuria. Chest X-ray was clear with no evidence of pulmonary infiltrations, nodules, cavitation or pleural effusion. Electrocardiogram showed left ventricular hypertrophy with right bundle branch block. The patient also had sensorineural hearing loss. A diagnosis of ANCA-associated scleritis was made and patient was treated with a combination of oral glucocorticoids and azathioprine. The patient had two episodes of anterior scleritis and developed bilateral peripheral ulcerative keratitis (PUK) which resulted in permanent visual impairment with no further progress. Ongoing rheumatology service work-up for systemic vasculitis could not classify the case. ANCA-associated vasculitis can have atypical ocular presentation and can be clinically misdiagnosed as conjunctivitis. Long term visual and systemic complications can be prevented with early detection and prompt immunosuppressive treatment.