OP5.2 | Systemic Associations in Episcleritis/Scleritis Referral — Summary & Reflection

KEY TAKEAWAYS

Scleritis is associated with a systemic connective tissue disease or vasculitis in approximately 50% of patients, making the systemic evaluation of every new scleritis patient a clinical imperative, not optional. Rheumatoid arthritis is the most common systemic association (20-30% of scleritis cases), particularly with necrotising subtypes and scleromalacia perforans. Granulomatosis with polyangiitis (GPA) — identified by c-ANCA (PR3-ANCA) positivity — is the must-not-miss vasculitis, as ocular scleritis may be its first visible manifestation while renal and pulmonary destruction proceeds silently. Relapsing polychondritis, SLE, IBD, and other vasculitides account for further cases. Episcleritis has milder systemic associations (IBD, rosacea, gout) and does not require routine investigation on a first, uncomplicated episode. The investigative panel for new scleritis includes RF, anti-CCP, ANA, c-ANCA, p-ANCA, ESR, CRP, CXR, urine analysis, and B-scan for posterior scleritis. Referral indications are stratified by urgency: all scleritis requires rheumatology referral; necrotising scleritis, peripheral ulcerative keratitis, and renal involvement require urgent or emergency referral. The ophthalmologist-rheumatologist partnership is the cornerstone of management, with each specialty monitoring distinct aspects of disease activity and coordinating steroid taper and systemic immunosuppression.

REFLECT

Think about a patient in your future practice who presents with a red eye and is diagnosed with scleritis. You know from the clinical features that this is a diffuse anterior scleritis. Your ANCA results come back with a weakly positive c-ANCA. The patient has no obvious systemic symptoms but mentions occasional shortness of breath on exertion that he has attributed to being unfit. Reflect on: How would the weakly-positive ANCA result change your clinical management compared to a clearly negative result? What additional history and investigations would you now prioritise? At what point would this become an emergency? Sketch the conversation you would have with the patient about the possibility of a systemic diagnosis — how do you communicate uncertainty (the c-ANCA may be a false positive) without either alarming the patient or minimising a potentially life-threatening finding?