To evaluate the relationship between associated medical conditions and scleritis-particularly, the timing of the diagnosis of these diseases.
Retrospective case series.
Patients with scleritis presenting to a single center over an 18-year period.
Medical records were reviewed for the presence of an associated infectious or rheumatic disease and for the timing of the diagnosis of the systemic disease relative to the presentation for evaluation of the scleritis.
Presence of an associated medical condition and timing of diagnosis relative to that of scleritis.
In a series of 243 patients with scleritis, 44.0% had an associated medical condition: 7.0%, an infection, and 37.0%, a rheumatic disease. The most frequent infection was herpes zoster, and the most frequent rheumatic disease was rheumatoid arthritis, present in 4.5% and 15.2% of patients, respectively. Of the 107 patients with an underlying disease, 77.6% had a previously diagnosed disease, 14.0% had their conditions diagnosed as a result of the initial evaluation, and 8.4% developed a systemic disease during follow-up. Systemic vasculitis was less likely to have been previously diagnosed than other rheumatic diseases (59.1% vs. 83.8%, P = 0.015) and more likely to be diagnosed by the initial diagnostic evaluation (27.3% vs. 8.8%, P = 0.027). Ten patients (4.1%) had a positive antineutrophil cytoplasmic antibody (ANCA) test result without clinical evidence of a systemic vasculitis. Four of 5 patients with a positive cytoplasmic ANCA test result but no clinical evidence of systemic vasculitis required immunosuppressive drugs for control of the scleritis, whereas 1 of the 5 patients with a positive perinuclear ANCA test result required immunosuppressive drugs. Among patients with no evident systemic disease after the initial diagnostic evaluation, the rate of occurrence of a rheumatic disease was 4% per person-year.
Although associated systemic diseases are frequent among patients with scleritis, the majority are previously diagnosed. Systemic vasculitis is less likely than other rheumatic diseases to have been previously diagnosed. Because vasculitis is a potentially life-threatening disorder, it should be a focus of the diagnostic evaluation.