Supernumerary Digit

The supernumerary finger, also called polydactyly, is a congenital variant in which the hand or foot has an extra digit beyond the usual number. It can be a complete, functional digit or just a small appendage of tissue.

How it appears: it is identified from birth and its form is highly variable; sometimes the extra digit is well formed and other times it is barely an outline attached by skin.

Common causes: it usually has a hereditary component and, at times, is associated with other developmental features, so a careful evaluation is advisable.

Evaluation falls to the pediatrician and the pediatric orthopedist, and when it affects the hand the hand surgeon may join. If your child has this feature, scheduling an early visit helps understand the case and plan appropriate follow-up.