Nail Involvement in Patients with Psoriatic Arthritis in Northern Iran.

Background: Psoriatic arthritis (PsA) results in an increased burden of psoriasis and impairs both quality of life and an individual's functional capacity. The relationship between nail involvement and PsA in psoriasis is not fully characterized.

Aim: To evaluate the frequency and characteristics of nail involvement in psoriatic patients and to assess the relationship with joint involvement.

Methods: A total of 197 patients with moderate-to-severe psoriasis were consecutively invited to participate in this cross-sectional study. The patients are divided into two groups: those with and those without psoriatic arthritis.

Results: 69.5% of psoriatic (137 out of 197) patients had nail involvement. The most common nail abnormality was onycholysis, followed by pitting and oil droplet changes. Nail involvement was more common in patients with psoriatic arthritis (82.1% versus 57.8%, p=0.001).

Conclusion: Nail involvement is commonly associated with PsA. Onycholysis, splinter hemorrhage, and oil drop were significantly more common in the PsA group as opposed to patients with just skin findings. In general, psoriatic patients with arthritis had more severe disease.