Pterygium of the nail is seen in: (A) Lichen planus, (B) Psoriasis, (C) Tinea unguium, (D) Alopecia areata
Answer is A. Pterygium of the nail is classically seen in lichen planus: Pterygium unguis (also known as "Dorsal pterygium") forms as a result of scarring between the proximal nailfold and matrix, with the classic example being lichen planus, though it has been repoed to occur as a result of sarcoidosis and Hansen's disease Ref Harrison 20th edition pg 1234