Joint pain and swelling

Definition
Pain and swelling, in joints.
Epidemiology
Joint pain especially is incredibly common. Joint swelling is less so, but the two are almost always related.
Pathophysiology
The pain can come from many causes; in destructive disease, its from nerve ending being exposed by damage to bone and cartilage, in non destructive conditions, I'm not sure where the pain comes from.
Clinical and Associated Features
The symptoms of joint pain will vary according to the cause. Symptoms like pain, swelling, stiffness, or warmth suggest joint inflammation.
May also be:
- redness,
- painful to touch
- reduced joint mobility.
To separate rheumatoid and osteoarthritis, Rheumatoid arthritis is classically stiff and painful in the morning, getting looser and less painful as they move through the day. Osteoarthritis may not present with stiffness, and gets worse throughout the day.
Differential Diagnosis
Degenerative
- Osteoarthritis
- General oldness, leading to worn out joints
Inflammatory:
- Rheumatoid Arthritis
- Other connective tissue disorders
- GI complaints like Coeliac's,Crohn's and Colitis
Infective:
- Joint infection
- Reactive arthritis
Others (less common):
- Allergic reaction - commonly to things like nuts, milk, caffeine, etc.
- Chronic Fatigue Syndrome
- Leukaemia
Investigations
Firstly check for inflammatory markers - ESR and CRP. Along with this, go for Rheumatoid factor. It's not very helpful often, but it can separate inflammatory conditions into seronegative and positive.
Secondly, X-rays can show destructive damage, and some soft tissue issues.
Management
Based on the cause. In allergy, avoid the allergen, and taking antihistamines. In inflammatory arthritis, start with NSAIDs, moving on all the way to immunosuppression.
Sometimes it may be necessary to undergo joint replacement, for example in severe hip or knee osteoarthritis.