Background: Psoriasis can present at any age. However, the disease onset appears to follow a bimodal distribution, peaking around 20–30 years of age and again around 50–60 years of age. A family history of the disease is common. Approximately 30% of patients have a first-degree relative with psoriasis, and the risk of psoriasis increases with the number of affected relatives a patient has. the etiology of psoriasis is still not fully comprehended but there is obviously a genetic component in the development of psoriasis. The genetic factor in psoriasis is a result of the combined action of multiple disease genes. Some of these genes control the severity of multiple diseases by regulating inflammation and immunity (severity genes), while others are specific to psoriasis. In most patients, nail psoriasis appears at the same time asor after cutaneous psoriasis. On occasions, however, it is the only manifestation of disease. The clinical presentations of nail psoriasis vary according to the affected area. Susceptible areas are the nailbed, the nail matrix, the hyponychium, and the nail folds Nail psoriasis severity is assessed by analyzing clinical features and extent of disease. A number of scales have been developed to facilitate standardized assessment. The Nail Psoriasis Severity Index (NAPSI) is the most widely used scale, but other options are the modified NAPSI and the fingernail physician global assessment.

Nail Psoriasis