Pterygium inversum unguis associated with stroke.

Pterygium inversum unguis (PIU) is an uncommon nail abnormality in which the distal nail bed adheres to the ventral surface of the nail plate with obliteration of the distal nail groove. This rare condition, whether congenital, acquired, or idiopathic, has been reported in a few patients. Because of the rarity of this condition, the exact origin remains speculative. In addition, there have been no histopathologic features described in PIU. We describe an unusual case of acquired PIU of the right fingernails alone associated with a cerebral vascular accident resulting in right-sided paralysis and sensory deficit. We also present the first histologic features of PIU.