Rheumatoid arthritis accounts for approximately 15 per cent of the SCE Rheumatology exam — the single largest topic. BSR guidelines on the management of RA with DMARDs and biologics are the primary UK reference, supplemented by EULAR recommendations for management and NICE technology appraisals governing drug access. This page covers the high-yield content.
Diagnosis and classification
RA is diagnosed clinically — there is no single diagnostic test. The ACR/EULAR 2010 classification criteria provide a scoring system based on joint involvement (number and size of affected joints), serology (RF and anti-CCP), acute phase reactants (CRP and ESR), and duration of symptoms (above or below 6 weeks). A score of 6 or above out of 10 classifies RA.
The exam tests the distinction between classification criteria (designed for research cohort homogeneity) and clinical diagnosis (which can be made in patients who do not meet formal classification criteria). A patient with a classic presentation of symmetrical small joint polyarthritis, positive anti-CCP, and raised CRP can be diagnosed with RA even if their total classification score is below 6.
Anti-CCP has higher specificity for RA than RF (approximately 95 per cent versus 80 per cent). A positive anti-CCP in the context of inflammatory arthritis is highly suggestive of RA. RF is positive in approximately 70 per cent of RA patients but is also positive in other conditions (Sjögren's, hepatitis C, cryoglobulinaemia, and in up to 10 per cent of the healthy population).
Treat-to-target
The BSR and EULAR both recommend a treat-to-target approach. The target is remission (DAS28 below 2.6) or low disease activity (DAS28 below 3.2) if remission is not achievable. Disease activity should be assessed every one to three months in active disease and treatment adjusted until the target is reached.
The DAS28 score incorporates tender joint count (28 joints), swollen joint count (28 joints), ESR or CRP, and a patient global assessment. The thresholds are: remission below 2.6, low disease activity 2.6 to 3.2, moderate 3.2 to 5.1, and high above 5.1.
The exam tests the DAS28 thresholds and the treat-to-target principle — specifically, that treatment should be escalated if the target is not achieved, not left unchanged because the patient is "stable" at moderate disease activity.
DMARD selection and sequencing
First-line: methotrexate is the anchor DMARD for RA. BSR recommends starting methotrexate as first-line therapy in all patients with newly diagnosed RA unless contraindicated. Starting dose is typically 7.5 to 10 mg weekly, titrated to 20 to 25 mg weekly. Folic acid 5 mg weekly (not on the methotrexate day) is co-prescribed to reduce side effects.
Monitoring: FBC, LFTs, and renal function at baseline, then every two weeks until on a stable dose for six weeks, then monthly for six months, then every two to three months thereafter. The exam tests the monitoring frequency — particularly the initial fortnightly monitoring.
If methotrexate is contraindicated or not tolerated: leflunomide or sulfasalazine are alternatives. Hydroxychloroquine can be used as monotherapy for very mild disease or as part of combination therapy.
Combination conventional DMARDs: methotrexate plus sulfasalazine plus hydroxychloroquine (triple therapy) is an option before biologic escalation. The evidence for triple therapy versus methotrexate plus biologic is debated, but BSR acknowledges triple therapy as a valid strategy.
Biologic eligibility (NICE)
Biologic therapy is indicated when the patient has failed two or more conventional DMARDs (including methotrexate unless contraindicated) and has a DAS28 above 5.1 on two occasions one month apart, or has a DAS28 of 3.2 to 5.1 with intolerance or contraindication to further conventional DMARDs.
First-line biologic options: TNF inhibitors (adalimumab, etanercept, infliximab, certolizumab, golimumab), IL-6 inhibitors (tocilizumab, sarilumab), B-cell depletion (rituximab), co-stimulation modulation (abatacept), or JAK inhibitors (baricitinib, tofacitinib, upadacitinib, filgotinib).
NICE does not mandate a specific sequencing among these classes. The choice depends on patient factors — comorbidities, route of administration preference, and safety profile. Rituximab is often preferred for patients with a history of lymphoma or recurrent infections. JAK inhibitors offer oral administration but carry specific safety considerations (VTE, herpes zoster, cardiovascular events — ORAL Surveillance data).
Response assessment: biologic efficacy is assessed at six months. A response is defined as a DAS28 improvement of 1.2 or more. If the response is inadequate, switch to an alternative biologic — either within class (second TNFi) or between classes.
Pregnancy and RA
Methotrexate and leflunomide are teratogenic and must be stopped before conception — methotrexate at least three months before, leflunomide requires washout with cholestyramine. Sulfasalazine and hydroxychloroquine are safe in pregnancy and breastfeeding. Among biologics, certolizumab has the most pregnancy safety data (minimal placental transfer due to its PEGylated Fab structure). TNF inhibitors should generally be stopped in the third trimester to avoid neonatal immunosuppression, but certolizumab can be continued throughout.
The exam frequently tests which DMARDs are safe in pregnancy (sulfasalazine, hydroxychloroquine, certolizumab) and which must be stopped (methotrexate, leflunomide, most biologics).
iatroX's SCE Rheumatology bank includes comprehensive RA content covering diagnosis, DAS28 targets, DMARD monitoring, biologic eligibility criteria, and pregnancy management. All included at £29 per month or £99 per year.