Prevalence of Inflammatory Rheumatic Diseases in a Rheumatologic outpatient clinic: analysis of 12626 cases

Inflammatory rheumatic diseases are a heterogeneous class of often chronic autoimmune disorders. They are among the most common chronic diseases. They cause major health problems in the general population. This study assessed the distribution of inflammatory systemic rheumatic diseases in a rheumatologicoutpatient clinic. The medical records of patients diagnosed with any type of inflammatory rheumatic disease between January 1, 2006 and December 31, 2016 in a non-hospital-based rheumatologic outpatient practice in Mashhad, Iran were retrospectively studied. Diagnoses were made using the agreed-upon classification criteria. Data regarding each patient’s diagnosis, age at onset of disease, and gender was extracted from their files. The total number of patients was 12,626. The most common diseases were rheumatoid arthritis (47.30%), spondyloarthropathies (17.23%), systemic lupus erythematosus (8.10%), gout (7.84%), and vasculitis (6.84%). Patients were aged from 1 to 93 years, with a mean age of 41.17±39.70 years. Most patients were in the third, fourth, and fifth decade of life. Sixty-four percent of all patients were female. The overall sex ratio (women to men) was 1.8:1. The proportion of women was 95% in Takayasu's arteritis, 92% in systemic lupus erythematosus, 87% in Sjögren’s syndrome, 78% in rheumatoid arthritis, and 24% in ankylosing spondylitis. The age at onset of inflammatory rheumatic diseases in Mashhad, Iran is lower than that in some other regions. The frequency of Behcet's disease, systemic lupus erythematosus, and systemic sclerosis was greater in this study than in most other studies, but gout, polymyalgia rheumatica, and psoriatic arthritis were less frequent in the current study.