Rheumatology and Immunology
Core framework
Approach with pattern recognition: which joints (small versus large, symmetric versus asymmetric, axial versus peripheral), which extra-articular features, and which serology. Then decide whether the process is inflammatory, mechanical, or crystal-related. Understand that autoimmune disease diagnosis is clinical with supportive serology - a positive antinuclear antibody alone is not a diagnosis.
Concepts examiners test
Rheumatoid arthritis: classification, extra-articular features, and the importance of early disease-modifying therapy. Systemic lupus erythematosus: criteria, complement consumption, lupus nephritis and its biopsy classes. Vasculitis: ANCA-associated and giant cell arteritis with its sight-threatening emergency and need for immediate steroids. Polymyalgia rheumatica versus rheumatoid arthritis. Crystal arthritis: gout and pseudogout with synovial fluid analysis. Spondyloarthritis and its association with HLA-B27. Also biologic therapy screening (tuberculosis, hepatitis) and drug monitoring.
Traps
- Giant cell arteritis with visual symptoms requires immediate high-dose steroids, not a wait for biopsy.
- A positive antinuclear antibody is common in healthy people - interpret in clinical context.
- Do not start tumour necrosis factor inhibitors without screening for latent tuberculosis and hepatitis B.
- Gout can be treated with urate-lowering therapy during an acute attack if already established; do not stop it abruptly.
- Hydroxychloroquine requires retinal monitoring; methotrexate requires folate and monitoring of liver and blood counts.
Worked rule of thumb
An elderly patient with new headache, jaw claudication and transient visual loss: start high-dose corticosteroids immediately, arrange temporal artery biopsy and urgent ophthalmology review. Steroids do not preclude biopsy if given within about two weeks.