Medicine

Last updated on: October 19th, 2021

Hi there!

You’re looking at a short reference article from Explain Medicine (one of four distinct learning formats available in Clinical Odyssey). Try it out, and have fun improving your clinical skills.

Rheumatoid arthritis

Clinicals - History

Introduction

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease of the joints that is of unknown etiology; systemic involvement may also occur. Genetically susceptible individuals experience dysregulation of both innate and adaptive immunity. This results in the aberrant production of inflammatory cytokines, resulting in chronic inflammation. In addition, these persons also develop autoimmunity against the synovial lining of the joints, bursae and tendon sheath. The combined effects of the above mechanisms results in synovitis, synovial proliferation, and the destruction of cartilage and subchondral bone.

Persistent symmetric polyarthritis and joint stiffness

Patients may experience joint swelling, and stiffness for a prolonged period (>1 hour) on waking. This may involve both the small and large joints. Classically, the small joints of the hands and feet are involved in a symmetrical pattern. Some patients may initially present with involvement of a single joint that then spreads; others have multiple joints involved from the beginning.

Constitutional symptoms

Fever and fatigability may occur. This is due to the systemic inflammatory response driven by inflammatory cytokines (i.e., TNF-alpha, Il-1 and IL-6) Cognitive impairment and anemia may also occur. This is due to the inflammation affecting the brain, liver and bone marrow.

Risk factor: smoking

Smoking increases the risk of developing RA by contributing to the formation of citrullinated proteins. Smokers also have a more severe course of rheumatoid arthritis.

Risk factor: female gender

Females are at a higher risk of developing RA. Multiple pregnancies increase this risk further . However, the use of oral contraceptive pills and a younger age at menarche is protective.

Risk factor: genetic susceptibility

The presence of the heterozygotic allele HLA DRB1*0401/*0404 confers an increased risk of developing RA.

Risk factor: middle age

The onset of RA peaks between the ages of 40 to 50 years.

Systemic involvement

Potential systemic manifestations include:

  1. Cardiovascular disease: myocardial infarction due to accelerated atherosclerosis;
  2. Ocular disease: sicca syndrome, conjunctivitis, episcleritis, scleritis;
  3. Pulmonary disease: Interstitial lung disease;
  4. Serositis: pleuritis, pericarditis, and ascites; and
  5. Vasculitis: small-vessel vasculitides involving the lungs, kidneys, joints, gastrointestinal tract, central nervous system, and skin.

Want to continue reading?

Subscribe to Clinical Odyssey today.
  • Enjoy unlimited access to 600+ learning modules.
  • Safely improve your skills, anytime and anywhere.
  • Get answers to your follow-up questions from practicing physicians.
Learn more ➜