[3]: 788 The condition may be present at birth or acquired, and may cause pain with manipulation of small objects, typing, and close manicuring of the nail.
Congenital pterygium inversum unguis is assumed to be brought on by an early abnormality in the fetal ridge and groove formation.
[6] Secondary pterygium inversum unguis is thought to be caused by abnormal distal circulation.
[7] A prominent hyperkeratotic stratum corneum with normal nail bed vasculature is seen upon histological analysis.
[5] The best way to address pterygium inversum unguis is unclear; many approaches, such as topical steroids, keratolytics, and electrocautery-assisted surgical excision, have been shown to be ineffective.