Pterygium Complicating Nail Psoriasis and Trachyonychia: Is It Rare?

Pterygium is an irreversible scarring of the nail matrix resulting in a split nail. The deformity is most often post-traumatic, though it can be the end result of aggressive inflammatory diseases involving the nail matrix like nail lichen planus, graft versus host disease, or autoimmune bullous disorders like cicatricial pemphigoid. It is thought to be a result of lymphocytic inflammation-mediated damage to the nail matrix, initiating a fibrotic process which slowly fuses the nail fold with the nail matrix and bed, destroying the nail plate. We report an interesting observation in a series of patients of various ages with nail and/or skin psoriasis, and trachyonychia associated with pterygium formation in multiple nails. Insidious progression to anonychia was also observed despite initiating adequate treatment. This report highlights the potential of irreversible nail damage occurring in reportedly benign nail conditions like psoriasis and trachyonychia, emphasizing the need for early recognition and aggressive management in such cases.