Comparative Study of Clinical and Dermoscopic Features in Nail Psoriasis

Nail changes have been reported in approximately 40% of psoriasis patients. Occasionally nail psoriasis may be the sole finding or the first presentation of the disease. Assessment of the nail changes associated with psoriasis can be done clinically, ultrasonographically, and most recently using a dermoscope. The aim of this study is to assess the dermoscopic features in nails of psoriasis as well as to compare the dermoscopic with the clinical findings. This study has also assessed the correlation between disease duration and the severity of skin and nail involvement.

A total of 50 patients with psoriatic nail changes were recruited in the study. The psoriasis area severity index (PASI) was used to assess the severity of the disease. The nail psoriasis severity index (NAPSI) was used to determine the severity of nail involvement. The patient's nails were examined both clinically and dermoscopically.

Pitting was the commonest feature (84%) noted both clinically and dermoscopically. A statistically significant higher NAPSI score (P < 0.05) was obtained by a dermoscope than by clinical examination. Salmon patch and splinter hemorrhage were better visualized using a dermoscope than by clinical evaluation (P < 0.05). The duration of the disease had a strong positive correlation (R = 0.901) with the duration of nail involvement whereas there was a weak correlation between the duration of the disease and the clinical NAPSI (R = 0.23) and dermoscopic NAPSI (R = 0.28). A weak positive correlation (R = 0.3) was noted between the PASI and NAPSI scores.

Dermoscopy of nails proved to be an efficient, supportive, easy, noninvasive method that provides a better insight into the subtle nail changes in psoriatic patients, which may have been missed clinically.