Acute Joint Pain

Question 1

What is the ‘must exclude diagnosis’ in any patient presenting with acute joint pain?

Answer 1

Septic arthritis

Question 2

Construct a differential diagnosis for acute joint pain by dividing it into articular, peri-articular and non-articular pathology.

Answer 2

- Articular
Trauma 
Gout 
Pseudogout
Septic arthritis 
Seronegative spondyloarthropathies 
Transient synovitis 
Others: amyloidosis, sarcoidosis, vasculitides, SLE, haemarthrosis
Peri-articular
Ligament injury
Tendinitis
Others: Bursitis, fasciitis, epicondylitis 
- Non-articular
Nerve entrapment 
Radiculopathy
Others: bone malignancy, osteomyelitis

Question 3

List the seronegative spondyloarthropathies.

Answer 3

Reactive arthritis
Ankylosing spondylitis
Psoriatic arthritis
Enteropathic arthritis

Question 4

List some key features of the history that are important to ask the patient about.

Answer 4

Pain
Trauma
Risk factors for gout 
Risk factors for septic arthritis 
Risk factors for haemarthrosis

Question 5

Describe different patterns of pain and how they relate to the causes of joint pain.

Answer 5

Worse with movement + better with rest = non-inflammatory (e.g. osteoarthritis)
Acute-onset = septic arthritis, gout/pseudogout, trauma
Insidious onset = bursitis, tendonitis (overuse)
Chronic onset = osteoarthritis

Question 6

List some risk factors for gout.

Answer 6

Thiazide diuretics
Chemotherapy
Chronic renal failure
Recent heavy alcohol intake

Question 7

List some risk factors for septic arthritis.

Answer 7

Prosthetic joints
Immunosuppression
Trauma

Question 8

List some risk factors for haemarthrosis.

Answer 8

Coagulopathy
Anticoagulants
Trauma

Question 9

List some significant features of the past medical history of a patient with joint pain.

Answer 9

Recent GI or urogenital infections (reactive arthritis or septic arthritis)
Previous episodes of joint pain
Rheumatological disease

Question 10

Which diseases are associated with sequential involvement of several joints?

Answer 10

Septic arthritis (gonococcal)
Rheumatic fever

Question 11

Which diseases are associated with simultaneous involvement of multiple joints?

Answer 11

Chronic polyarthritis (e.g. rheumatoid arthritis, psoriatic arthritis)

Question 12

List some key features of the drug history of a patient with joint pain.

Answer 12

Thiazide diuretics, aspirin and chemotherapy – increases uric acid levels and precipitates gout
Steroids – increase risk of atypical fractures

Question 13

Outline a basic approach to joint examination.

Answer 13

Look
Feel
Move

Question 14

Describe briefly how articular conditions can be distinguished from peri-articular conditions on joint examination.

Answer 14

Articular – more likely to see diffuse joint inflammation and pain on active AND passive motion
Peri-articular – focal point of tenderness on palpation and pain is usually much worse on active movement

Question 15

List some features of joint disease that you may see on the skin of a patient.

Answer 15

Tophi
Rheumatoid nodules
Rash (e.g. psoriasis, SLE)

Question 16

List three signs of psoriasis that can be seen on the nails.

Answer 16

Pitting
Onycholysis
Subungual hyperkeratosis

Question 17

Why is uveitis a significant sign in a patient with joint pain?

Answer 17

Associated with HLA-B27 positive inflammatory arthropathies

Question 18

Why are mouth ulcers a significant sign in patients with joint pain?

Answer 18

Associated with inflammatory bowel disease, which, in turn, is associated with polyarthropathy

Question 19

Why is pulmonary fibrosis a significant finding in patients with joint pain?

Answer 19

It can be caused by rheumatological disease (e.g. rheumatoid arthritis)
It can also be caused by the treatment of certain rheumatological diseases (e.g. methotrexate)

Question 20

Describe the use of arthrocentesis in the diagnosis of crystal arthritis.

Answer 20

Gout – needle-shaped crystals with negative birefringence

Pseudogout – rhomboid-shaped crystals with positive birefringence

Question 21

Describe the aspirate in septic arthritis.

Answer 21

Cloudy
High WCC (especially neutrophils)
Bacteria visible on microscopy

Question 22

What would the presence of blood in a joint aspirate suggest?

Answer 22

Haemarthrosis (due to trauma or coagulopathy)

Question 23

What would the presence of white cells in the absence of crystals, blood and infection in a joint aspirate suggest?

Answer 23

Reactive arthritis 
Enteropathic arthritis 
Psoriatic arthritis 
Rheumatic fever 
Rheumatoid arthritis

Question 24

What would a non-inflammatory aspirate (normal WCC and clear) suggest?

Answer 24

Trauma

Osteoarthritis

Question 25

What are the five different types of psoriatic arthritis?

Answer 25

``` Asymmetrical oligoarthritis Symmetrical polyarthritis Distal interphalangeal joint predominance Arthritis mutilans Psoriatic spondylitis ```

Question 26

List some other investigations that may be useful in a patient with joint pain.

Answer 26

Cultures – to check for sepsis or to identify GI or urogenital infection Bloods FBC, CRP and ESR – to check for signs of infection/inflammation Clotting screen – check for coagulopathy that could cause haemarthrosis

Question 27

List some specific rheumatological investigations that may be performed in a patient with joint pain.

Answer 27

Rheumatoid factor Anti-cyclic citrullinated peptide antibodies ANA

Question 28

Why is measuring serum urate rarely useful in the acute setting?

Answer 28

Serum urate is usually normal/low in acute gout

Question 29

Which joint is most commonly affected in gout?

Answer 29

Metatarsophalangeal joint of the big toe (podagra)

Question 30

Outline the acute management of gout.

Answer 30

Colchicine NSAIDs Corticosteroid injections

Question 31

Describe the chronic management of gout.

Answer 31

Drugs that decrease production of urate – allopurinol + febuxostat (xanthine oxidase inhibitors) Drugs that increase excretion of urate – sulfinpyrazone + probenecid Drugs that increase degradation of urate – rasburicase

Question 32

Describe the typical presentation of septic arthritis.

Answer 32

Very painful joint developed acutely with/without trauma It will be red, hot, swollen and tender Painful to both active and passive movement

Question 33

What is bicipital tendonitis caused by?

Answer 33

Overuse (repetitive lifting motions)

Question 34

What triad of symptoms is associated with reactive arthritis?

Answer 34

Uveitis Urethritis Arthritis

Question 35

Which types of infections are associated with reactive arthritis?

Answer 35

``` GI infections (e.g. Salmonella and Shigella) Urogenital infections (e.g. Chlamydia trachomatis) ```

Question 36

Which organisms most commonly cause septic arthritis in: Native joints Prosthetic joints

Answer 36

- Native joints Staphylococcus aureus - Prosthetic joints Staphylococcus epidermidis

Question 37

List some radiographic features of osteoarthritis.

Answer 37

Loss of joint space Osteophytes Subchondral sclerosis Subchondral cysts