Rheumatoid arthritis and pyoderma gangrenosum: a population-based case-control study.

RA increases the odds of developing PG by more than threefold. Physicians managing patients with RA should be aware of this increased burden. Patients with RA may be advised to avoid additional precipitating factors of PG. Key Points • The odds of developing PG are increased by more than threefold in patients with RA. • PG followed the diagnosis of RA in the majority of patients with these coexistent conditions by an average latency of 9.2 years. • Patients with RA-associated were older relative to other patients with PG at the onset of PG.