This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of skin, Subject name: Dental
Pterygium of nail is characteristically seen in - 
Select and explain. 
A. Lichen planus, B. Psoriasis, C. Tinea unguium, D. Alopecia areata
A: Lichen planus
Answer: A: Lichen planus 
Explanation: pterygium unguis is a wing like adhesion between the proximal nail fold and nail bed. Psoriasis-nail pitting. Page no.243. Reference Harrison20th edition