Nail changes are found in about ______ cases of psoriasis:

Nail involvement is seen in association with all type of psoriasis and is frequently present with psoriatic ahropathy. About half of all patients with psoriasis have fingernail involvement, appearing as punctate pitting, onycholysis, nail thickening, or subungual hyperkeratosis. About 5-10% of patients with psoriasis have associated ahralgias, and these are most often found in patients with fingernail involvement