Nail Changes in Psoriasis: Correlation Between Onychoscopy and NAPSI Scoring

Background: Nail changes in psoriasis can present as a diagnostic challenge especially in the absence of cutaneous features. They occur in approximately 40% of psoriatics and in 5% as the sole presentation. Onychoscopy as a diagnostic tool aids in better visualization of nail matrix and bed abnormalities in psoriasis patients with nail involvement. Aim: To study onychoscopic features of nails in psoriasis and correlate it clinically using nail psoriasis severity index (NAPSI). Materials and Methods: A total of 60 patients of psoriasis with nail changes were recruited in this hospital based cross-sectional study over a period of one year. Cutaneous severity was assessed using psoriasis area severity index (PASI). NAPSI was used to determine the severity of nail involvement. Nails of the patients with psoriasis were examined clinically and onychoscopically. Statistical analysis was done using the software R i386.3.6.3. Results: Pitting was the most common nail change observed on clinical and onychoscopic examination, seen in 90% and 95% patients respectively. Leuconychia, red spots in lunula, onycholysis, and splinter hemorrhages were better visualized on onychoscopy. A statistically significant higher NAPSI (P < 0.05) was obtained on onychoscopy. There was a positive co- relation between the cutaneous severity of psoriasis and the extent of nail involvement. Conclusion: Onychoscopic examination coupled with NAPSI in nail psoriasis serves as a useful guide to assess the nail involvement and provides a better insight into the subtle nail changes in psoriatics which could have been missed clinically. Limitations: Small study population, lack of age and sex matched control group.