What does pterygium refer to?

Pterygium specifically refers to the condition where there is an abnormal adherence of the skin to the nail plate, which can lead to the separation of the nail plate from the surrounding skin and cuticle area. This condition typically manifests as the skin growing over the nail bed, potentially disrupting nail growth and affecting the overall appearance of the nail. Understanding this condition is important for manicurists, as it requires proper assessment and potentially specialized care to avoid further complications.

The other options do not correctly describe pterygium. The absence of skin around the nail or the complete absence of the nail plate represents different nail disorders or conditions entirely. Therefore, the focus on the separation aspect in the correct choice encapsulates the essence of pterygium effectively.