Today we discussed a case of newly-diagnosed inflammatory bowel disease (Crohn's) in a 71 year-old man presenting with polyarthritis and erythema nodosum. Interestingly, his older age and predominately extraintestinal manifestations of disease led to delay in diagnosis. IBD has, however, been suggested to have a bimodal distribution, with most diagnoses occurring in young adulthood but about 10% of cases in the age 50-70 group.
Some questions to help narrow the differential in patients with polyarthralgia:
- Have symptoms been occurring chronically? (Rheumatologic causes usually are > 6 weeks)
- Or are symptoms acute and migratory? (this is characteristic of viral arthritis, disseminated gonnococcal infection, and rheumatic fever)
- Which joints are involved? Large joints? Small joints? Is there symmetry? (RA is usually symmetrical)
- What is the effect of immobility on pain? (not moving/prolonged stiffness is a sign of an inflammatory cause whereas improvement with rest indicates osteoarthritis)
- Is there synovitis on exam? (signs of inflammation raise the likelihood of systemic rheumatic disease--but also viral etiologies)
- Are there multiple tender points diffusely on exam? (common in fibromyalgia, but also worth considering viral causes as well as OA, hypothyroidism, metabolic bone disease, depression)
- Are there extra-articular signs/symptoms? (multisystem involvement are common in patients with rheumatic disease or systemic illness)
Check out a nice review of the diagnostic approach to polyarticular joint pain from AAFP here.