Rheumatoid Arthritis

Rheumatoid Arthritis - Articular (joints)

Rheumatoid arthritis and osteoarthritis compared
Rheumatoid arthritis is a chronic, inflammatory, multisystem autoimmune disorder. It is commonly polyarticular; that is, it affects many joints. Inflammation, soft tissue swelling, and the involvement of multiple joints are common signs and symptoms that distinguish rheumatoid and other inflammmatory arthritis from non-inflammatory arthritis such as osteoarthritis. The joints are usually affected initially asymmetrically and then in a symmetrical fashion as the disease progresses. The pain generally improves with use of the affected joints, and there is usually stiffness of all joints in the morning that lasts over one hour. Thus, the pain of rheumatoid arthritis is usually worse in the morning compared to the classic pain of osteoarthritis where the pain worsens over the day as the joints are used.

Extra-articular manifestations also distinguish rheumatoid arthritis from osteoarthritis (hence it is a multisystemic disease). For example, most RA patients also suffer with anemia, either as a consequence of the disease itself (anaemia of chronic disease) or as a consequence of gastrointestinal bleeding as a side effect of drugs used in treatment, especially NSAIDs used for analgesia. Hepatosplenomegaly may occur with concurrent leukopaenia (Felty's syndrome), and lymphocytic infiltration may affect the salivary and lacrimal glands (Sjögren's syndrome). Pericarditis, pleurisy, alveolitis, scleritis, and subcutaneous nodules are other features.

Rheumatoid Arthritis  Deformities

As the pathology progresses the inflammatory activity leads to erosion and destruction of the joint surface, which impairs their range of movement and leads to deformity. The fingers are typically deviated towards the little finger (ulnar deviation) and can assume unnatural shapes. Classical deformities in rheumatoid arthritis are the Boutonniere deformity (Hyperflexion at the proximal interphalangeal joint with hyperextension at the distal interphalangeal joint), swan neck deformity (Hyperextension at the proximal interphalangeal joint, hyperflexion at the distal interphalangeal joint). The thumb may develop a "Z-Thumb" deformity with fixed flexion and subluxation at the metacarpophalangeal joint, and hyperextension at the IP joint.

Rheumatoid Arthritis - Cutaneous manifestations

The cutaneous (strictly speaking subcutaneous) feature most characteristic of rheumatoid arthritis is the rheumatoid nodule. The initial pathologic process in nodule formation is unknown but is thought to be related to small-vessel inflammation. The mature lesion is defined by an area of central necrosis surrounded by palisading macrophages and fibroblasts and a cuff of cellular connective tissue and chronic inflammatory cells. The typical rheumatoid nodule may be a few millimetres to a few centimetres in diameter and is usually found over bony prominences, such as the olecranon, the calcaneum at the Achilles tendon insertion, the metacarpophalangeal joints, or other areas that sustain repeated mechanical stress. Nodules are associated with a positive RF titer and severe erosive arthritis. They can rarely occur throughout the body in internal organs.
Rheumatoid arthritis is associated with a variety of forms of vasculitis. A benign form occurs as microinfarcts around the nailfolds. More severe forms include livedo reticularis, which is a network (reticulum) of erythematous to purplish discoloration of the skin due to the presence of an obliterative cutaneous capillaropathy. (This rash is also otherwise associated with the antiphospholipid-antibody syndrome, a hypercoagulable state linked to antiphospholipid antibodies and characterized by recurrent vascular thrombosis and second trimester miscarriages.
Rheumatoid arthritis is rarely associated with pyoderma gangrenosum, a necrotizing, ulcerative, noninfectious neutrophilic dermatosis. Sweet's syndrome, a neutrophilic dermatosis usually associated with myeloproliferative disorders, viral infections, and drug reactions, also occurs in rheumatoid arthritis (6). Other complications include erythema nodosum, lobular panniculitis, atrophy of digital skin, palmar erythema, diffuse thinning (rice paper skin), and skin fragility.

Rheumatoid Arthritis - Extra-articular (elsewhere)

Pulmonary
The lungs may become involved as a part of the primary disease process or as a consequence of therapy. Fibrosis may occur spontaneously or as a consequence of therapy (for example methotrexate). Caplan's nodules are found as are pulmonary effusions.
Renal
Amyloidosis can occur.
Cardiovascular
Possible complications that may arise include: pericarditis, endocarditis, left ventricular failure, valvulitis and fibrosis. The risk of cardiovascular, specifically myocardial infarction (heart attack) or congestive heart failure are greater in individuals with RA. Over 1/3 of deaths of people with RA are directly attributable to cardiovascular death.
Ocular
Keratoconjunctivitis sicca (dry eyes), scleritis, episcleritis and scleromalacia.
Gastrointestinal
Felty syndrome, anemia
Neurological
Peripheral neuropathy and mononeuritis multiplex may occur. The most common problem is carpal tunnel syndrome due to compression of the median nerve by swelling around the wrist. Atlanto-axial subluxation can occur, owing to erosion of the odontoid process and or/transverse ligaments in the cervical spine's connection to the skull. Such an erosion (>3mm) can give rise to vertebrae slipping over one another and compressing the spinal cord. At first the patient experiences clumsiness but without due care this can progress to quadriplegia.
Vasculitis
Vasculitis in rheumatoid arthritis is common. It is typically presents as vasculitic nailfold infarcts.
Osteoporosis
Osteoporosis classically occurs in RA around inflamed joints. It is postulated to be partially caused by inflammatory cytokines.
Lymphoma
The incidence of lymphoma is increased in RA as it is in most autoimmune conditions.

Rheumatoid Arthritis - Epidemiology

The incidence of RA is in the region of 3 cases per 10,000 population per annum. Onset is uncommon under the age of 15 and from then on the incidence rises with age until the age of 80. The prevalence rate is 1%, with women affected three to five times as often as men. It is 4 times more common in smokers than non-smokers. Some Native American groups have higher prevalence rates (5-6%) and black persons from the Caribbean region have lower prevalence rates. First-degree relatives prevalence rate is 2-3% and disease concordance in monozygotic twins is approximately 15-20%.

It is strongly associated with the inherited tissue type Major histocompatibility complex (MHC) antigen HLA-DR4 (most specifically DR0401 and 0404) — hence family history is an important risk factor.

Pictures of Rheumatoid Arthritis Hands