Inflammatory Autoimmune Seronegative Arthritis Flashcards
Psoriatic Arthritis Reactive Arthritis Ankylosing Spondylitis
Outline the epidemiology of psoriatic arthritis.
- Psoriatic arthritis occurs equally in men and women, although earlier disease onset is observed in males
- The incidence of psoriatic arthritis in women peaks in the 6th decade, mirroring an age-specific rise in the incidence of the skin disease in females
What are the risk factors of psoriatic arthritis (2)?
- Psoriasis
- FHx of psoriasis or psoriatic arthritis
Outline the pathogenesis of psoriatic arthritis.
The aetiology of psoriatic arthritis is largely unknown
* Trauma to joints or tendons has been implicated in triggering psoriatic arthritis, as have infections (particularly HIV infection). Infection possibly triggers psoriatic arthritis by exposing antigens to the innate immune system and leading to expression of the psoriatic phenotype.
Outline the pathophysiology of psoriatic arthritis.
Dominant pathogenic pathway is interleukin 17/ interleukin 23
- Psoriatic arthritis is a disease of the cellular immune system, with CD8+ T cells playing a primary role in both the skin and synovium
- Compared with rheumatoid synovium, psoriatic synovium is characterised by hypervascularity and morphologically tortuous vessels
- Cytokine interaction with the receptor activator of nuclear factor kappa B (RANKL) leads to osteoclast proliferation and activation, contributing to erosions and osteolysis
- This is manifested clinically by the radiological changes of arthritis mutilans, including pencil-in-cup deformities, as well as new-bone formation of periostitis
The presence of distal interphalangeal (DIP) joint involvement and dactylitis uniquely distinguishes psoriatic arthritis from rheumatoid arthritis. These manifestations are related, respectively, to extensor tendon enthesitis at the nail bed and flexor tenosynovitis of the entire digit
How would a patient with psoriatic arthritis presented (5)?
- Personal or Fx of psoriasis
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Joint pain and stiffness
- Inflammatory joint pain is characterised by prolonged morning stiffness (>30 minutes), improvement with use, and recurrence with prolonged rest.
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Peripheral arthritis
- Usually indicated by swelling and tenderness of individual joints (synovitis) during inspection and palpation.
- Psoriatic arthritis frequently presents in a pattern of monoarticular or oligoarticular joint involvement. In patients with multiple joints involved, the pattern lacks the symmetry of rheumatoid arthritis.
- Dactylitis (sausage finger) due to enthesitis
- Hx of scalp or nail problems
- Patients may not know they have psoriasis. The disease may be misinterpreted as scalp dandruff, seborrhoea, or onychomycosis.
What investigations are suggested in suspected psoriatic arthritis (8)?
- Plain film X-rays of the hands and feet
- Erythrocyte sedimentation rate and C-reactive protein (ESR & CRP)
- Rheumatoid factor (RF)
- anticyclic citrullinated peptide (Anti-CCP) antibody
- Lipid profile
- Fasting blood glucose
- Uric acid level
- Synovial fluid aspiration and analysis
What would an X-Ray show in a patient with psoriatic arthritis?
- Erosion in the distal interphalangeal (DIP) joint and periarticular new-bone formation
- Osteolysis and pencil-in-cup deformity in advanced disease
What would an erythrocyte sedimentation rate and C-reactive protein (ESR & CRP) test show in a patient with psoriatic arthritis?
- Normal or elevated
What would a rheumatoid factor (RF) test show in a patient with psoriatic arthritis?
- Positive or negative
What would an anticyclic citrullinated peptide (Anti-CCP) antibody test show in a patient with psoriatic arthritis?
- Negative
What would a lipid profile test show in a patient with psoriatic arthritis?
- Normal or hyperlipidaemia
What would a fasting blood glucose test show in a patient with psoriatic arthritis?
- Normal or hyperglycaemia
What would a uric acid level test show in a patient with psoriatic arthritis?
- Normal or elevated
What would a synovial fluid aspiration and analysis show in a patient with psoriatic arthritis?
- Absence of monosodium urate crystals
What is the treatment of acute psoriatic arthritis (1st line 1 / Consider 2)?
1st line:
* Non-steroidal anti-inflammatory drugs (NSAIDs)
Consider:
* Physiotherapy
* Intra-articular corticosteroid injection
Outline the epidemiology of reactive arthritis.
- Unclear