Baby born with a bald spot on the head

A bald patch on a newborn’s head is common and, in most cases, temporary. It usually falls into one of two very different categories: a normal, self-resolving hair cycle called telogen effluvium, or a much rarer group of conditions where hair follicles didn’t fully form, grouped under the term hypotrichosis. Telling the two apart matters, because one needs nothing more than time, while the other needs a pediatrician or dermatologist to properly evaluate.

Bald spot from telogen effluvium

This is by far the more common cause, typically appearing within the first six months of life. Hair grows in cycles, and telogen is the resting phase in which a hair sits in its follicle without growing before eventually shedding. The hormonal shift a baby goes through right after birth can push a large share of hairs into this resting phase at once, which shows up as a sudden bald patch, often at the back of the head from repeated pressure while lying down. It typically resolves on its own within a few months as normal hair growth resumes — there’s usually nothing to treat.

Bald spot from hypotrichosis

Hypotrichosis is a different situation: rather than hair being shed, the follicles themselves didn’t develop, so there was little or no hair there to begin with. It’s much less common than telogen effluvium and is usually linked to genetic factors or a developmental issue during pregnancy. Because it can occasionally accompany other developmental features, a baby with a persistent bald patch that doesn’t follow the typical telogen-effluvium pattern should be evaluated by a pediatrician, who can refer to a dermatologist or geneticist if needed. A few recognized forms include:

Aplasia cutis congenita

A localized area, most often on the scalp, where the skin didn’t fully form before birth — it can appear as a bald patch with no follicles, or occasionally as an open area that heals into a bald scar. Its exact cause isn’t always identified. Larger or open lesions need prompt evaluation to manage healing and reduce infection risk.

Triangular alopecia

A patch, usually near the temple, where the scalp skin is normal but follicles never developed there. Unlike aplasia cutis, there’s no wound involved. It’s permanent on its own, though hair transplant procedures can address it later in life if desired.

Congenital atrichia

Here, a baby is born with normal hair but loses it in early childhood, linked to a genetic defect affecting the hair follicle. It’s a distinct condition from the others in this list since there’s no bald patch at birth, and it currently has no established treatment to reverse it.

Other causes of hair loss or thinning in babies and young children

• Alopecia areata – an autoimmune condition causing sudden, patchy hair loss, sometimes affecting eyebrows and eyelashes too. Unlike hypotrichosis, it can respond to treatment under a dermatologist’s care.
• Friction or positional hair loss – thinning where a baby’s head repeatedly rubs against a mattress or car seat. This resolves once the baby spends more time upright and mobile, and generally isn’t a medical concern.
• Tight hairstyling – in older children, hair pulled tightly (braids, ponytails) can cause traction alopecia at the hairline; it’s reversible if caught early.
• Trichotillomania – a hair-pulling habit some children develop, often linked to stress or anxiety rather than a scalp condition. It responds best to support from a pediatrician or child psychologist rather than any topical treatment.

When to see a doctor

Most bald patches in babies are telogen effluvium and resolve without any intervention. See a pediatrician if the patch is present at birth with no hair follicles visible, if there’s an open wound or unusual skin texture at the site, if hair loss is spreading rather than staying in one spot, or if it hasn’t improved by around 6–9 months of age. A pediatrician can determine whether it’s a normal variant or something that needs a dermatology referral.