Tender and swollen joint counts are poorly associated with disability in chikungunya arthritis compared to rheumatoid arthritis

Chronic rheumatological manifestations similar to those of rheumatoid arthritis (RA) are described after chikungunya virus infection. We aimed to compare the relevance of joint counts and symptoms to clinical outcomes in RA and chronic chikungunya disease. Forty patients with chronic chikungunya arthralgia and 40 patients with RA were enrolled in a cross-sectional study. The association of tenderness and swelling, clinically assessed in 28 joints, and patient evaluations of pain and musculoskeletal stiffness with modified Health Assessment Questionnaire (HAQ) and quality of life (QoL) assessments were investigated. Tender and swollen joint counts, pain and stiffness scores were all associated with the HAQ disability index in RA (all r > 0.55, p ≤ 0.0002), but only stiffness was significantly associated with disability in chikungunya (r = 0.38, p = 0.02). Joint counts, pain and stiffness were also associated with most QoL domains in RA patients. In contrast, in chikungunya disease, tender joint counts were associated only with one QoL domain and swollen joints for none, while pain and stiffness were associated with several domains. Our results confirm the relevance of joint counts in RA, but suggest that in chronic chikungunya disease, joint counts have more limited value. Stiffness and pain score may be more important to quantify chikungunya arthritis impact.