J Gen Intern Med 31 (8): 970, 2016. doi: 10.1007 / s11606 - 016 - 3628-z Nail deformities associated with dermatologic conditions In psoriasis, nails may have a number of changes, including irregular pits, oil spots (localized areas of tan-brown discoloration), separation of part of the nail from the nail bed (onycholysis), and thickening and crumbling of the nail plate.