Diagnosis of early rheumatoid arthritis: what the non-specialist needs to know

TLDR

Rheumatoid arthritis is a chronic inflammatory disease affecting about 1 % of the population, causing irreversible joint damage, systemic complications, and higher mortality, and early joint damage has prompted guidelines to refer patients for specialist care within 6–8 weeks of symptom onset. This article examines the challenges of early RA diagnosis, illustrated through a case of polyarthritis. An audit revealed that patients were referred on average 16 weeks after symptom onset, largely due to late referral rather than patient delay, with many referral letters lacking or misidentifying the diagnosis because RA lacks disease‑specific features and presents variably.

Abstract

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease that affects about 1% of the population. It leads to irreversible joint damage and systemic complications, and the age-adjusted mortality of those affected exceeds that of the general population.1–3 When joint damage was seen to be an early feature of the disease,4–12 rheumatologists put forward the point at which they prescribed disease-modifying antirheumatic drugs (DMARD), in the hope of slowing or even arresting disease progression. Patients in whom DMARD therapy is introduced early have better function and radiological outcome in the long-term than those in whom it is delayed.13–19 It was for these reasons that a SIGN (Scottish Intercollegiate Guideline Network) guideline20 in 2000 indicated that a patient with inflammatory arthritis lasting >6–8 weeks should be referred for a specialist (rheumatology) opinion. However, a recent audit in our unit showed that such patients were referred after a mean of 16 weeks (interquartile range 6–34) from onset of symptoms.21 Other studies suggest that the long lag between symptom onset and the diagnosis of RA is mainly due to late referral rather than patient delay in reporting symptoms or long waits for outpatient appointments.22 Moreover, in most referral letters from general practitioners, a tentative rheumatological diagnosis is either not stated or stated wrongly.23,24 The reason is clear: RA has no disease-specific diagnostic features25 and patients can present with a wide range of manifestations. In this article I discuss the difficulties of early diagnosis, taking an illustrative case of polyarthritis (inflammation of more than four joints), the commonest presentation.