Which systemic conditions should I consider in a patient presenting with episcleritis?

When a patient presents with episcleritis, several systemic conditions should be considered as potential underlying causes. These include autoimmune and inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus, and other connective tissue disorders. Additionally, inflammatory bowel diseases like Crohn's disease and ulcerative colitis are relevant systemic associations. Vasculitides, including granulomatosis with polyangiitis, may also present with episcleritis. Infectious causes, although less common, such as herpes zoster or Lyme disease, should be considered in the appropriate clinical context. Furthermore, conditions like rosacea and other dermatological disorders can be linked to episcleritis. It is important to conduct a thorough systemic review and targeted investigations to identify these associations, as management may require addressing the underlying systemic disease alongside symptomatic treatment of episcleritis NICE CKS Denk et al. 1997Tappeiner et al. 2016Héron & Bourcier 2017.