How is nail psoriasis?

Pitting: punctate depressions of the nail plate surface • Onycholysis: separation of the nail plate from the nail bed • Subungual hyperkeratosis: abnormal keratinization of the distal nail bed • Oil drop sign: irregular area of yellow-orange discoloration visible through the nail plate • Most of the lesions in nail psoriasis arise from disease in the nail matrix and/or nail bed • The nail plate is formed primarily from the nail matrix with secondary contribution from the nail bed