Nail psoriasis alters the way your toenails and fingernails look. They may get thick and change color or shape. They also can feel tender and hurt. You may get ridges or grooves in your nails, or pitting (small pinprick holes) on the surface of your nails. Chalky white material can gather under your nail, causing it to lift away from the skin. About a third of people with nail psoriasis also get a fungal infection that can make your nails extra thick. They may also get brittle and break.