Multiple triangular lunula unguis: a specific finding for the nail-patella syndrome.

In this case presentation recognition of multiple triangular lunula unguis led to the diagnosis of the rare nail-patella syndrome (NPS). A single triangular lunula may be traumatic in origin, but multiple, with apex pointing toward the free edge of the nail, must be considered part of the NPS especially when combined with absence of the distal interphalangeal joint creases.