Rheumatoid arthritis

Question 1

What is it?

Answer 1

Rheumatoid arthritis is an autoimmune condition that causes chronic inflammation of the synovial lining of the joints, tendon sheaths and bursa. It is an inflammatory arthritis. Synovial inflammation is called synovitis. Rheumatoid arthritis tends to be symmetrical and affects multiple joints

Question 2

Genetic Associations?

Answer 2

HLA DR4 (a gene often present in RF positive patients)
HLA DR1 (a gene occasionally present in RA patients)

Question 3

Antibodies present in RA?

Answer 3

Rheumatoid Factor (RF) is an autoantibody presenting in around 70% of RA patients. It is an autoantibody that targets the Fc portion of the IgG antibody. Rheumatoid factor is most often IgM however they can be any class of immunoglobulin.

Cyclic citrullinated peptide antibodies (anti-CCP antibodies) are autoantibodies that are more sensitive and specific to rheumatoid arthritis than rheumatoid factor

Question 4

Presentation

Answer 4

Pain
Swelling
Stiffness
Patients usually attend complaining of pain and stiffness in the small joints of the hands and feet, typically the wrist, ankle, MCP and PIP joints in the hands. They can also present with larger joints affected such as the knees, shoulders and elbows. The onset can be very rapid (i.e. overnight) or over months to years.

There are also associated systemic symptoms:

Fatigue
Weight loss
Flu like illness
Muscles aches and weakness

Question 5

Palindromic Rheumatism?

Answer 5

This involves self limiting short episodes of inflammatory arthritis with joint pain, stiffness and swelling typically affecting only a few joints. The episodes only last 1-2 days and then completely resolve. Having positive antibodies (RF and anti-CCP) may indicate that it will progress to full rheumatoid arthritis.

Question 6

Common Joints Affected?

Answer 6

Proximal Interphalangeal Joints (PIP) joints
Metacarpophalangeal (MCP) joints
Wrist and ankle
Metatarsophalangeal joints
Cervical spine
Large joints can also be affected such as the knee, hips and shoulders

Question 7

Atlantoaxial Subluxation?

Answer 7

Atlantoaxial subluxation occurs in the cervical spine. The axis (C2) and the odontoid peg shift within the atlas (C1). This is caused by local synovitis and damage to the ligaments and bursa around the odontoid peg of the axis and the atlas. Subluxation can cause spinal cord compression and is an emergency. This is particularly important if the patient is having a general anaesthetic and requiring intubation. MRI scans can visualise changes in these areas as part of pre-operative assessment.

Question 8

Signs in the Hands

Answer 8

Palpation of the synovium in around joints when the disease is active will give a “boggy” feeling related to the inflammation and swelling.

Key changes to look for and mention when examining someone with rheumatoid arthritis are:

Z shaped deformity to the thumb
Swan neck deformity (hyperextended PIP with flexed DIP)
Boutonnieres deformity (hyperextended DIP with flexed PIP)
Ulnar deviation of the fingers at the knuckle (MCP joints)

Question 9

Boutonnieres deformity?

Answer 9

Boutonnieres deformity is due to a tear in the central slip of the extensor components of the fingers. This means that when the patient tries to straighten their finger, the lateral tendons that go around the PIP (called the flexor digitorum superficialis tendons) pull on the distal phalynx without any other supporting structure, causing the DIPs to extend and the PIP to flex.

Question 10

Extra-articular Manifestations?

Answer 10

Pulmonary fibrosis with pulmonary nodules (Caplan’s syndrome)
Bronchiolitis obliterans (inflammation causing small airway destruction)
Felty’s syndrome (RA, neutropenia and splenomegaly)
Secondary Sjogren’s Syndrome (AKA sicca syndrome)
Anaemia of chronic disease
Cardiovascular disease
Episcleritis and scleritis
Rheumatoid nodules
Lymphadenopathy
Carpel tunnel syndrome
Amyloidosis

Question 11

Investigations

Answer 11

Check rheumatoid factor
If RF negative, check anti-CCP antibodies
Inflammatory markers such as CRP and ESR
X-ray of hands and feet

Question 12

Xray changes

Answer 12

Joint destruction and deformity
Soft tissue swelling
Periarticular osteopenia
Boney erosions

Question 13

NICE guidelines for Disease Modifying Anti-Rheumatic Drugs

Answer 13

First line is monotherapy with methotrexate, leflunomide or sulfasalazine. Hydroxychloroquine can be considered in mild disease and is considered the “mildest” anti rheumatic drug.
Second line is 2 of these used in combination.
Third line is methotrexate plus a biological therapy, usually a TNF inhibitor.
Fourth line is methotrexate plus rituximab