Approach to managing patients with nail psoriasis.

Psoriasis is a chronic inflammatory skin condition that affects approximately 2% of the population. Up to 50% of patients with psoriasis have concurrent nail psoriasis, with a lifetime incidence of 80% to 90%. Up to 30% of patients with skin psoriasis also have psoriatic arthritis (PsA) and of these, approximately 80% have nail disease. However, nail involvement is often overlooked by physicians, despite the significant burden it places on patients as a result of functional impairment of manual dexterity, pain and psychological stress. Affected nail plates often thicken and crumble, and because they are very visible, patients are usually concerned about the appearance of their nails, often causing them to avoid normal day-to-day activities (including work). In the longer-term, nail involvement may be a signal of a more severe form of psoriasis or a precursor of PsA. Conventional treatment of nail psoriasis is generally considered inconvenient by patients, and it is limited by adverse effects and often a reduction in efficacy over time. There is also a lack of controlled clinical trials' data and no consistent treatment approach has been advocated. Recently, the effects of biologic agents targeted against tumour necrosis factor alpha (TNFalpha) on nail psoriasis have been investigated. The multicentre, double-blind EXPRESS [European Infliximab for Psoriasis (Remicade) Efficacy and Safety Study] trial revealed that infliximab 5 mg/kg at weeks 0, 2, 6, and then every 8 weeks significantly improved nail psoriasis, evaluated using the Nail Psoriasis Severity Index (NAPSI) in 378 patients with moderate to severe psoriasis. Significant improvement was reported as early as week 10, and at week 50 full nail clearance was evident in 45% of patients receiving infliximab. There is also evidence from small studies that infliximab significantly improves nail lesions and quality of life in patients with nail psoriasis. There is a need for improving the awareness of nail psoriasis and its impact on patients' quality of life. Moreover, the potential role for nail involvement as a link between psoriasis and PsA underlines its importance and the need for effective management. Infliximab has been shown to improve psoriatic nail lesions and quality of life, and it should be considered as one of the most appropriate available treatment options for the many patients with this distressing condition.