Nail ridging in rheumatoid arthritis patients and relation to disease activity: An integrated rheumatology-dermatology multi-centre study

Aim of the work

To evaluate the frequency of nail ridging (NR) in patients with rheumatoid arthritis (RA) and to study its relation to disease activity.

Patients and methods

230 RA patients and 97 matched controls from Helwan, Ain Shams and Mansoura university hospitals were studied. Disease activity score (DAS28) was assessed. NR has been searched for in all patients. The number of affected fingers was recorded. NR was determined by a magnifying lens, seen by naked eye or seen and felt. Dermoscopic photography of the NR using Dermalite DL4 3Gen dermatoscope has been recorded.

Results

The median age of patients was 49 years (42–58 years); they were 221 females and 19 males (F:M 11.1:1) with a disease duration 9 years (5–11 years). Their DAS28 was 3.6 (2.9–4.6). NR was significantly increased in RA cases vs. control; 73% vs 20%; p < 0.001. In patients, NR was detected by a magnifying lens in 32.6%, seen in 27% and seen and felt in 13.5%. Joint deformities were significantly higher in those with NR. DAS28 was a significant independent predictor of NR; for every one-point increase in DAS28, there was a 153 times higher odds to exhibit NR at a sensitivity of 93.5%, specificity 80.3% and at a diagnostic accuracy of 90%.

Conclusion

NR is a frequent finding in RA. An integrated rheumatological- dermatological clinical evaluation may be helpful and further studies are required to prove the importance of this sign for follow up of RA patients.