Q&A: Nonarticular Manifestations of Rheumatoid Arthritis

Although rheumatoid arthritis (RA) develops its central pathology within the synovium of diarthrodial joints, many nonarticular organs become involved, particularly in patients with severe joint disease. Despite the differences between the normal form and function of joints and, for example, the bone marrow, it is becoming clearer that the same cytokines that drive synovial pathology are also responsible for generating pathology in extraarticular tissues.

This article is for Medical Students & Professionals

This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Rheumatoid Arthritis article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Systemic and nonarticular manifestations of rheumatoid arthritis
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

Systemic and nonarticular manifestations of rheumatoid arthritis

Involvement of the musculoskeletal system other than joints (eg, bone and muscle) and of organs not considered part of the musculoskeletal system (eg, skin, eye, lung, heart, kidney, blood vessels, salivary glands, central and peripheral nervous systems, and bone marrow) occurs in about 40 percent of patients with RA over a lifetime of disease. There is some limited evidence that some of them, such as rheumatoid nodules and vasculitis, may be diminishing in frequency since the mid-1990s.

Risk factors for systemic, extraarticular disease include age, presence of rheumatoid factor (RF) or antinuclear antibodies, human leukocyte antigen (HLA)-DRB1 ‘shared epitope' alleles, early disability, and smoking. Patients with severe extraarticular RA often have high levels of RF at presentation of systemic manifestations and are more likely to have circulating antibodies against citrullinated proteins than are patients with RA but without extraarticular disease.

Extraarticular involvement in RA is a marker of disease severity and is associated with increased overall morbidity and premature mortality. Successful management of systemic manifestations of RA is predicated upon control of the underlying joint disease and often includes glucocorticoid and immunosuppressive treatments.

MCQ exam: clinical scenario

A strong association with Rheumatoid arthritis is a feature of:

a) Orbital pseudotumor
b) Uveitis
c) Episcleritis
d) Scleritis
e) Conjunctivitis

MCQ exam: answer

The correct answer is D.

MCQ exam: explanation

Scleritis, often associated with rheumatoid arthritis and other immune disorders, is a potentially destructive inflammation of the collagen in the deep episcleral vessels and the sclera. The eye is sometimes painful. Fortunately, scleritis is rare.

An experienced observer is required to make the diagnosis.

Scleritis coexists with a serious systemic disease in almost one-half of cases; frequently the underlying problem is a connective tissue disorder. Rheumatoid arthritis occurs almost one-third of the time in patients suffering from scleritis. Other connective tissue diseases seen with scleritis include: Systemic lupus erythematosus (SLE), Polyarteritis nodosa, Ankylosing spondylitis, Wegener's granulomatosis, Relapsing polychondritis, Sarcoidosis.

Reference(s)
1). UpToDate: Overview of the systemic and nonarticular manifestations of rheumatoid arthritis. Available online: https://www.uptodate.com/contents/overview-of-the-systemic-and-nonarticular-manifestations-of-rheumatoid-arthritis