Summary

Nail psoriasis (NP) is a common manifestation of psoriasis, affecting up to 80–90% of patients with psoriatic arthritis and up to 60% of those with cutaneous psoriasis. Isolated NP also occurs in 5–10% of cases. It significantly impacts quality of life and may indicate or precede psoriatic arthritis. In this review, we summarized the clinical features of NP, highlighting patterns of matrix and nail bed involvement, and discussed differential diagnosis with onychomycosis. We outlined current topical, intralesional, systemic, and non-pharmacological treatment options, and proposed an evidence-based approach to diagnosis and management.

Psoriasis is a chronic immuno-inflammatory skin disorder characterized by rapid keratinocyte proliferation, forming thick, red patches with silvery scales. It affects 2–3% of the population, impacting skin, nails, and joints. Pathogenesis involves genetic, environmental, and immunological factors [1]. Triggers such as infections (especially Streptococcus), skin injuries, medications, stress, and alcohol can initiate or worsen the condition [1]. Psoriasis may follow a stable course or present in cycles of flare-ups and remissions. Skin involvement may manifest in any body area but is most common on the knees, elbows, trunk, and scalp [1]. Nail involvement appears in up to 60% of those with cutaneous psoriasis and 80% of those with psoriatic arthritis (PsA), with an 80–90% lifetime incidence [2,3]. Isolated nail psoriasis (NP), defined as nail changes without cutaneous psoriasis or with limited body surface involvement (< 5%), occurs in 5–10% of patients [4,5].