Neonatal occipital alopecia, also known as transient neonatal hair loss and friction alopecia, is a patch of alopecia – most commonly of the occipital area – that occurs in early infancy. This pattern of neonatal alopecia was originally attributed to pressure or friction from lying in a supine position. However, a localized telogen effluvium more accurately explains this common phenomenon. During fetal development, hair follicles cover the head in a cephalo-caudal pattern by 18-20 weeks. The hair roots of the frontal and parietal scalp enter telogen around 26-28 weeks. The hair roots of the occipital scalp remain in anagen until birth. Therefore a localized telogen effluvium of the occipital scalp can be appreciated 8-12 weeks later.

Transient neonatal hair loss typically occurs 8-12 weeks after birth. However, neonates can be born with this localized alopecia. Darkly pigmented neonates are born with more hairs in anagen, and the conversion to telogen is delayed compared to lighter-skinned neonates. Consequently, transient neonatal hair loss occurs later in more darkly pigmented neonates.

The hair loss typically presents as a well-demarcated patch of non-scarring alopecia, most commonly in the occipital area, although parietal involvement is occasionally seen.