Arthralgia is a general term which describes pain in one or more joints with or without joint inflammation.
Causes of arthralgia
1. Degenerative – Osteoarthritis (OA), thyroid disease, acromegaly.
2. Inflammatory – Rheumatoid arthritis (RA), Systemic lupus erythematosus (SLE), Psoriatic arthritis, sickle cell disease, Lyme disease, hemophilia, inflammatory bowel disease, Reiter’s syndrome, Ankylosing spondylitis, sarcoidosis Rheumatic fever.
3. Crystal induced – Gout, Pseudogout
4. Infection – Tuberculosis, Syphilis, Gonorrhoea, typhoid, septic arthritis
5. Neuropathic – (Charcot’s joints)- Tabes dorsalis, syringomyelia
6. Metabolic bone disease – Osteomalacia
7. Trauma – Fracture, dislocation.
Approach to case taking and examination
* Anatomic localization of the complaint (articular vs. non articular)
* Determination of nature of pathological process (inflammatory vs. non inflammatory)
* Determination of extent of involvement (monarticular, polyarticular, focal, widespread)
* Determination of chronology (acute vs. chronic)
* Formulation of a differential diagnosis)
Key points of consideration
Dermographics – Aspects of patient profile can provide important information-
Age – SLE commonly present between 2nd & 4th decades, RA is commoner between 4th & 6th decades, OA in 7th & 8th decades SLE. Rheumatic fever and Reiter’s syndrome are common in young; fibromyalgia in middle age; and OA and polymyalgia rheumatica in old age.
Sex – Gout and spondyloarthropathies (ankylosing spondylitis & Reiter’s syndrome) are more common in men; RA and fibromyalgia in women.
Family history– familial aggregation is seen in ankylosing spondylitis, gout, RA, and Heberden’s nodes of OA.
Life style factors – Dietary history is important in gout, as a diet high in purines can precipitate an attack in susceptive individuals. Predisposing risk factors (sexual practices, IV drug abuse) need to be identified for Reiter’s syndrome and septic arthritis.
Compare the joints on both sides of the body.
Inspection – Look for swelling or deformity. Inflammation is often associated with redness, tenderness and warmth of the joint. Record the overall pattern of joint involvement – symmetrical in RA, asymmetrical in psoriatic arthritis or gout, predominantly lower limbs in seronegative (non rheumatoid) Spondyloarthropathies (e.g.-Reiter’s disease).
Palpation – Check for tenderness. Determine whether the swelling is due to bony enlargement or osteophytes (Heberden’s nodes in DA), to synovial thickening (inflammatory arthritis) or to synovial effusion. Gross disorganization of a joint, generally foot and ankle joints, associated with loss of deep pain and position sense is seen in neuropathic (Charcot’s) joints.
Assessment of joint tenderness
Grade I – Patient says joint is tender
Grade II – Patient winces
Grade III – Patient winces & withdraws the part
Grade IV – Patient will not allow the part to be touched.
Grade IV tenderness occurs only in septic arthritis, crystal arthritis and rheumatic fever. In gout, overlying skin is dry; but moist in other two condition.
Joint Crepitus – Detected feeling the joint with one hand while it is passively moved with the other. It may indicate DA or loose bodies in joint space.
Range of Movement – perform both active & passive movement.
Extra Articular Features of Joint Disease –
* Subcutaneous nodules – Gouty tophi, rheumatoid nodules, nodules in SLE
* Cutaneous vasculitic lesions – in RA, SLE and polyarteritis nodosa
* Lymphadenopathy – Proximal to an inflamed joints in septic arthritis; also in RA.
* Tendon sheath effusions
* Enlarged bursae-over pressure areas.
Tests in support of inflammatory disease
* ESR – elevated in inflammatory conditions
* CRP – (c-reactive protein) – more specific acute phase “indicator than ESR.
* Serum complement – low levels reflect activation due to immune complex deposition as in autoimmune diseases (SLE)
Specific diagnostic tests – should be carried out only if there is substantial clinical evidence suggesting a relevant diagnosis.
* Rheumatoid factor – (RA factor) – Ig M RA factor is found in 80% patients with RA and may be found in low titers in SLE, Sjogren’s syndrome, TB, leprosy, chronic pulmonary disease.
* Antinuclear antibodies – (ANA) – Useful screening test for SLE, positive in upto 90% of cases. May also be seen in 20% patients with RA, polymyositis, scleroderma, chronic hepatic or renal disorders.
* Human leukocyte antigen (HLA) typing – HLA-B27 is found in 95% of patients with ankylosing spondylitis but is also found in 8% of normal population.
* Antistreptolysin – O – (ASO)- a titre greater than 1/200 and rising on repeat testing after 2 weeks indicates a recent hemolytic streptococcal infection, and a pointer to rheumatic fever.
* Uric acid – A consistently normal plasma uric acid level effectively excludes the diagnosis of untreated gout. Raised levels however, do not establish in themselves the diagnosis of gout.
* Plain X-ray- is most appropriate in evaluation of trauma, suspected chronic infection or monarticular involvement. In most inflammatory disorders early radiography is rarely helpful. As disease progresses, calcification joint space narrowing erosions or subchondral cysts may be seen. for evaluating polyarthritis, three routine films should be asked for – both hands & wrists on one plate, both feet on another and are full pelvis to show sacroiliac & hip joints.
* Ultrasound – for defining soft tissue structures for any abnormality.
* Computed tomography – most useful in assessment of axial skeleton
* Magnetic resonance imagine – of particular value in non-invasive assessment of disc disease, spinal infection and most sensitive technique for avascular necrosis. More sensitive than CT for diagnosing soft tissue injuries & synovitis.
Synovial fluid examination
* Monoarthritis (acute or chronic)
* Trauma with joint effusion
* Monoarthritis in a pattern with chronic polyarthritis
* Suspicion of joint infection, crystal induced arthritis or hemarthrosis