Patients with comorbid rheumatoid arthritis are predisposed to peritonsillar abscess: real-world evidence.

PURPOSE The peritonsillar abscess (PTA)-rheumatoid arthritis (RA) association remains unclear. Here, the effects of RA on PTA incidence and prognosis are elucidated. METHODS We compared PTA incidence and prognosis of 30,706 RFCIP-registered patients with RA (RA cohort) with matched individuals without RA from another database of 1 million randomly selected people representing Taiwan's population (non-RA cohort). RESULTS The RA cohort had significantly higher PTA incidence [incidence rate ratio (IRR) (95% CI) 1.73 (1.10-2.71), P = 0.017) and cumulative incidence (P = 0.016, Kaplan-Meier curves). Cox regression analyses demonstrated RA cohort to have an estimated 1.72-fold increased PTA risk (95% CI 1.09-2.69, P = 0.019). PTA was more likely within the first 5 years of RA diagnosis (for < 1, 1-5, and ≥ 5 postdiagnosis years, IRRs: 2.67, 2.31, and 1.10, respectively, and P = 0.063, 0.021, and 0.794, respectively; average onset duration: 4.3 ± 3.3 years after RA diagnosis). PTA increased length of hospital stay significantly and risk of complication with deep neck infection nonsignificantly [6.5 ± 4.5 vs 4.6 ± 2.8 days (P = 0.045) and 18.52% vs 7.81% (P = 0.155), respectively]. Moreover, RA-cohort patients not receiving RA therapy exhibited 5.06-fold higher PTA risk than those receiving RA-related therapy (95% CI 1.75-14.62, P = 0.003). CONCLUSIONS In patients with RA, PTA incidence is the highest within 5 years of RA diagnosis, and RA therapy is essential for reducing PTA risk. LEVEL OF EVIDENCE 4.