ABSTRACT
Birth or first months of life; rare cases with lateonset presentation.
• Symmetrical, progressive thickening of all fingernails and toenails (main clinical feature: 97%– 100%): The distal two-thirds of the nails are yellow-brown, thick and dystrophic, distal subungual keratinous material elevates and transversally arches the nail plate (pincer nails) (Figures 8.1 through 8.3).
