Reactive Arthritis Flashcards
Define Reactive Arthritis and compare it with Septic Arthritis
Sterile inflammation in joints following infection
- Urogenital (e.g. Chlamydia)
- Gastrointestinal (e.g. Salmonella, Shigella, Campylobacter)
Occurs in young adults with a genetic predisposition (HLA-B27) with an environmental trigger (infection)
Symptoms follow 1-4 weeks after infection
Seronegative spondyloarthropathy
What are the clinical features that are observed?
Arthritis
- Asymmetrical, Oligoarthritis (<5), typically lower limbs affected
Enthesitis (inflammation of the entheses - tendons or ligaments insertions into the bone)
- Achilles tendonitis (heel pain), Dactylitis (swollen fingers), Plantar fasciitis – metatarsalgia (painful feet)
Spondylitis (inflammation of the spine)
- Spondylitis, Sacroiliac joints inflammation
Extra-articular features
- Sterile conjunctivitis
- Sterile urethritis
- Circinate balanitis
- Keratoderma blennorrhagicum (rash on hands and feet)
What is the investigation and treatment of Reactive Arthritis?
Investigations
- Microbial cultures
- Serology (HIV, Hep C)
- Immunology (RF, HLA-B27)
- Synovial fluid examination (pus in septic arthritis)
Treatment
- NSAIDs, intra-articular corticosteroid therapy (articular ) for pain
- Antibiotics are no use since the infection is Sterile
- Symptomatic (extra-articular) (topical steroids)
Compare Reumatoid Arthritis to Reactive Arthritis
What are the HLA molecules in Rheumatology ?
HLA Molecules in Rheumatology
- HLA alleles code for regions of the MHC molecules
- Role of MHC: present antigens to T cells so that they can recognise the antigens and generate an immune response
THREE major HLA associations:
- Rheumatoid Arthritis – HLA-DR4
- SLE – HLA-DR3
- Ankylosing Spondylitis – HLA-B27
Certain mutations in the MHC molecule leads to MHC presenting antigens in such a way that they trigger an exaggerated immune response
E.g. antigen bound to an MHC molecule with the HLA-DR4 allele can trigger a CD4+ T cell response, leading to rheumatoid arthritisr
