Psoriatic arthritis Flashcards
what is the definition of Psoriatic arthritis?
Psoriatic arthritis is a chronic inflammatory joint disease associated with psoriasis. It is a seronegative inflammatory arthritis differentiated from rheumatoid arthritis (RA) by several clinical features. These include a frequent oligoarticular or monoarticular initial pattern of joint involvement, as well as distal interphalangeal joint (DIP) involvement.
what is the epidemiology of psoriatic arthritis?
Hospital based patients
Earlier onset in males
50-60yrs
More common further north of equator
what is the aetiology of psoriatic arthritis?
Molecular mimicry
Mis-folding theory
HLA B27 heavy chain homodimer hypothesis
The aetiology of psoriatic arthritis is largely unknown. Psoriatic arthritis falls into the spectrum of the spondyloarthropathies. There are strong genetic influences, but these are far more complicated than simply a relationship to human leukocyte antigen (HLA)-B27. There is an increased risk of psoriasis (30% to 50%) or psoriatic arthritis (15%) in first-degree relatives. Genetic links to the major histocompatibility complex (MHC) class 1 alleles at the HLA-B and HLA-C loci have been identified for both psoriasis and psoriatic arthritis. The associations are complex, with some alleles increasing the risk of psoriasis and others contributing to arthritis.
what are the risk factors for psoriatic arthritis?
Psoriasis
Family history
History of joint and tendon trauma, HIV infection
what is the pathophysiology of psoriatic arthritis?
Mutilans
Dactylitis
Asymmetrical
HLA B27 tissue type
Psoriatic arthritis is a disease of the cellular immune system, with CD8+ T cells playing a primary role in both the skin and synovium. These cells have been demonstrated to be predominantly activated, clonally expanded memory T cells.
Compared with rheumatoid synovium, psoriatic synovium is characterised by hypervascularity and morphologically tortuous vessels. Angiogenic growth factors, including vascular endothelial growth factor (VEGF) and transforming growth factor (TGF) beta, are over-expressed in psoriatic tissue and not only contribute to the vascular changes but, together with tumour necrosis factor (TNF), contribute to the characteristic bone changes of psoriatic arthritis.
what are the key presentations of psoriatic arthritis?
RA like (symmetrical seronegative polyarthritis) Skin, nail and scalp psoriasis Family history Joint pain or stiffness Peripheral arthritis Dactylitis
what are the signs of psoriatic arthritis?
Peripheral arthritis Dactylitis RA like Skin, nail and scalp psoriasis Family history
what are the symptoms of psoriatic arthritis?
Joint pain and stiffness
what are the first line and gold standard investigations for psoriatic arthritis?
Plain film x-rays of hands and feet - erosion in the distal interphalangeal (DIP) joint and periarticular new-bone formation; osteolysis and pencil-in-cup deformity in advanced disease
ESR, CRP - CRP may not be raised, ESR raised or normal
RF - positive or negative
Anticyclic citrullinated peptide antibody - negative
Lipid profile - normal or high
Fasting blood glucose - normal or high
Uric acid level - normal or high
Synovial fluid aspiration and analysis - absence of urate crystals
what are the differential diagnoses for psoriatic arthritis?
RA, gout, erosive arthritis
how is psoriatic arthritis managed?
Limited:
NSAIDs, physio, intra articular corticosteroid injections
Progressive, dactylitis, spondylitis, enthesitis:
Methotrexate (DMARDs), NSAIDs, physio, intra articular corticosteroid injection, anti TNF drugs
how is psoriatic arthritis monitored?
Although some patients may spontaneously go into remission, the majority of cases persist and potentially progress, leading to impaired function. Therefore, disease and drug monitoring are recommended on a regular basis.
what are the complications of psoriatic arthritis?
Drugs can cause low WBC count
CVD, methotrexate hepatotoxicity, treatment related malignancy
what is the prognosis of psoriatic arthritis?
20% of patients develop progressive and disabling arthritis
