Difference Between Lupus and Rheumatoid Arthritis

Lupus vs Rheumatoid Arthritis

Both rheumatoid arthritis and lupus arthritis affect the peripheral joints. Both present with pain, swelling, and stiffness, and both arthritis have systemic manifestations. Though they present with similar symptoms, clinically rheumatoid arthritis and lupus are different. This article will discuss both rheumatoid arthritis and lupus and the differences between them in detail, highlighting their clinical features, symptoms, investigation and diagnosis, prognosis, and also the course of treatment/management they require.

Rheumatoid Arthritis

Rheumatoid arthritis is a persistent, deforming arthritis. It usually affects both sides at once. (Ex: rheumatoid arthritis of both wrist joints). Normally it involves joints at body extremities. (Ex: fingers, toes, ankle and wrist). Rheumatoid arthritis occurs most commonly in the fifth decade. It affects females more than males. Smokers are at a higher risk of getting rheumatoid arthritis. It usually presents with swollen, painful, stiff hands and feet. Rheumatoid symptoms are worse in the morning. Sometimes rheumatoid arthritis affects larger joints too. Apart from this typical presentation, there are some atypical presentations, as well.

Rheumatoid arthritis can rarely present as recurrent polyarthritis of various joints, persistent mono-arthritis, systemic illness with minimal joint problems, vague limb girdle pain, and sudden onset widespread arthritis. There are three characteristic joint deformities in established rheumatoid arthritis. They are Boutonniere’s deformity, swan neck deformity, and Z thumb deformity. The combination of hyper flexed proximal inter-phalangeal joint with hyper extended distal inter-phalangeal joint is called Boutonniere’s deformity. This can occur in 2nd to 5th fingers. The combination of hyper extended proximal inter-phalangeal joint with hyper flexed distal inter-phalangeal joint is called swan neck deformity. The combination of hyper flexed carpo-metacarpal joint, hyper flexed metacarpo-phalangeal joint with hyper extended inter-phalangeal joint of the thumb is called Z thumb. Apart from joint features there can be low hemoglobin, small nodules under the skin, lymph node enlargement, carpal tunnel syndrome, low white blood cell count, weight loss, painful red eyes, dry eyes, difficulty in breathing, chest pain, weak bones, and frequent fractures in rheumatoid arthritis.

The X-rays of joints show the loosening of joints and bone erosions. Regular exercise is essential to warm up joints and reduce pain. Joint splints take the strain off affected joints. Steroid injections reduce joint inflammation. NSAIDs reduce joint inflammation, as well. Disease modifying drugs like sulfasalazine, methotrexate, and ciclosporin interfere with disease mechanisms and slow down the progression of the illness.

Lupus Arthritis

Systemic lupus erythematosus is a multisystem disorder. Susceptible individuals form antibodies against self-molecules. Therefore, tissues all over the body show signs of inflammation. Arthritis in systemic lupus erythematosus is non-erosive. Arthritis does not destroy joint cartilages and articular surfaces of bones. Typically the disease involves two or more joints. They are tender, painful and stiff. Fluid can accumulate in the joint space resulting in effusion. 90% of patients with systemic lupus erythematosus show joint involvement. The joint capsule can get loosened (subluxation). This can deform the joint. This is called Jaccoud’s arthropathy. Parts of bones near involved joints can die (aseptic necrosis).

What is the difference between Lupus and Rheumatoid Arthritis?

• Lupus arthritis (LA) is rare, but rheumatoid arthritis (RA) is common.

• Lupus arthritis does not destroy joints while rheumatoid arthritis does.

• Lupus arthritis may be unilateral while rheumatoid arthritis is bilateral.

• Rheumatoid arthritis symptoms are worse in the morning while Lupus arthritis symptoms are more diffuse throughout the day.

• All patients with systemic lupus erythematosus do not get arthritis, but all rheumatoid arthritis patients have joint involvement.

• Lupus arthritis patients test positive for anti-nuclear antibodies while rheumatoid arthritis patients do not.

• All patients with rheumatoid arthritis are rheumatoid factor positive while only 40% of systemic lupus erythematosus are rheumatoid factor positive.