Ultrasound imaging of psoriatic nails

Abstract

Psoriasis is a common disease in dermatologic practice that affects approximately 2 % of the population, with a rising incidence over the years. Nail involvement has long been recognized as a common manifestation of psoriasis, occurring in up to 50 % of patients with an estimated lifetime incidence of 80–90 %. Nail psoriasis occurs more frequently in patients with severe disease such as those with psoriatic arthritis, with a prevalence of 70–80 % in this latter group. However, nail psoriasis also occurs in 40 % of patients with mild psoriasis (PASI ≤10). In patients with moderate to severe psoriasis, approximately 82 % have nail psoriasis symptoms. Importantly, between 1 and 5 % of patients have affected nails without skin lesions. Biopsies are difficult to perform in nails since they may leave permanent cosmetic sequels; therefore, to have at our disposal a noninvasive window to unveil the anatomic details of the nail unit and their pathologies would be of great benefit.