Pterygium colli is a congenital skin fold that runs along the sides of the neck down to the shoulders. It involves an ectopic fibrotic facial band superficial to the trapezius muscle. Excess hair-bearing skin is also present and extends down the cervical region well beyond the normal hairline. The phenotype is HP_0000465 (Webbed neck). Also known as: Neck webbing, Pterygium colli.