The Dermoscopic Findings of Nail Psoriasis and Their Relationship with Disease Severity

Background: Dermoscope is a non-invasive innovation in the field of dermatology. It emerged as an aid in the diagnosis of cutaneous malignant tumors like melanoma and basal cell carcinoma, and pre-malignant conditions like actinic keratosis. In the last years, the utility of the dermoscope had extended beyond the established boundaries. It may also act as a supportive tool for the examination of nail changes associated with various dermatological conditions. Aim of the study: This study was planned to evaluate the dermoscopic findings in psoriatic finger nail and to compare them with clinical findings and determine the relationship with disease severity. Patients and methods: Forty-four patients were included in this study; demographic data, including the name, age, gender, duration of the disease, other current medical illnesses or systemic medication, as well as the type of psoriasis, were recorded. Disease severity was determined according to PASI score. Patients’ finger nails thoroughly cleaned with spirit to remove debris, dirt or external applications. Then were examined by naked eyes and dermoscopically. Nail psoriasis severity index (NAPSI) scores were calculated both clinically and dermoscopically, both specific and non-specific findings of nail psoriasis were recorded. Results: The most common clinical and dermoscopical finding was pitting (77.27%, 86.36% respectively), there was no statistically significant difference between clinical and dermoscopical NAPSI (p=0.45). There was positive correlation between PASI and NAPSI scores both clinically (r=0.458, p<0.001) and dermoscopically (r=0.421, p<0.002). Oil spots and splinter hemorrhages were seen more frequently with the dermoscopy (p=0.031, p<0.001 respectively). Oil spots was found more frequently during Onychoscopic examination of patients with severe cutaneous disease (PASI>10). Two novel Onychoscopic findings were described for the first time during this study. Conclusion: Nail dermoscopy should be considered as a preferable method in examining a patient with nail psoriasis, and as a supportive and non-invasive procedure in cases of isolated nail involvement where clinical diagnosis of nail psoriasis is suspicious.