What are the implications of a flat spot on an infant's head, also known as positional plagiocephaly?

Positional Plagiocephaly: Clinical Implications and Management

A flat spot on an infant's head (positional plagiocephaly) is a benign cosmetic condition that spontaneously improves in most cases, resolving from 20% prevalence at 8 months to only 3% by 24 months of age, with no impact on brain development or neurological outcomes. 1

Natural History and Prognosis

• Positional plagiocephaly has no consequences on brain development and is purely an aesthetic issue 2
• The condition improves dramatically with time: incidence decreases spontaneously from 20% at 8 months to 3% at 24 months in healthy children 1
• This reassuring natural history should guide your counseling with parents, emphasizing that most cases resolve without intervention 1

Clinical Diagnosis

• Clinical examination by an experienced provider is sufficient for diagnosis; imaging is rarely necessary 3, 4
• Positional plagiocephaly presents as unilateral parieto-occipital flattening with rhomboid-like cranial shift, anterior displacement of the ipsilateral ear, and ipsilateral forehead bossing 1
• Brachycephaly (bilateral flattening) shows occipital flattening with anterior-posterior foreshortening 1, 3
• The critical distinction is ruling out craniosynostosis, which requires surgical intervention 3
• If clinical examination is equivocal, use skull X-rays or ultrasound first—these are almost always sufficient and minimize radiation exposure 4
• Reserve CT scans only for cases where X-rays/ultrasound are non-diagnostic and craniosynostosis must be definitively excluded 3, 4

Risk Factors

• Positional plagiocephaly is associated with supine sleeping position (OR: 2.5), though back-sleeping must continue for SIDS prevention 1
• Most likely to develop when: head position is not varied during sleep, minimal awake tummy time occurs, and infant is not held upright when awake 1
• Higher rates occur in children with developmental delay or neurologic injury, though causality is unproven 1
• Additional risk factors include first birth, assisted labor, multiple pregnancy, prematurity, and congenital muscular torticollis 5

Treatment Algorithm

Mild Cases (Early Detection)

• Start with repositioning education: vary head position during sleep, ensure supervised awake tummy time, and hold infant upright when not sleeping 1
• Repositioning is effective as sole therapy for mild deformity, particularly when initiated early 1
• Success rates for acceptable cranial shape may reach 92% with appropriate early treatment 6

Moderate Cases

• Physical therapy is superior to repositioning alone based on Class I evidence and should be the preferred intervention 1, 3
• Physical therapy programs outperform simple repositioning education in randomized trials 1
• Treatment typically involves stretching exercises combined with positioning strategies 2, 6

Severe or Refractory Cases

• Helmet (orthotic) therapy corrects asymmetry more rapidly and to a greater degree than repositioning, though this requires 3 months of treatment 1, 2
• Most studies comparing helmets to repositioning show helmets achieve better correction in less time 1
• Helmet therapy is particularly indicated when conservative measures fail or for severe deformity 2, 7

Critical Safety Considerations

• Never use soft positioning devices or pillows in the infant's sleeping environment—this contradicts AAP safe sleep guidelines and increases SIDS risk 1, 3
• Despite one European trial suggesting bedding pillows were superior to stretching exercises, the Congress of Neurological Surgeons explicitly recommends against any sleep positioning device 1
• Continue back-sleeping for all infants to prevent SIDS; the benefits vastly outweigh the cosmetic risk of plagiocephaly 1
• Supervised, awake tummy time is essential both for preventing plagiocephaly and facilitating motor development 1

Common Pitfalls to Avoid

• Failing to distinguish positional plagiocephaly from craniosynostosis, which requires surgical intervention 3
• Over-relying on repositioning alone for moderate-to-severe cases when physical therapy or helmet therapy would be more effective 1, 3
• Ordering CT scans unnecessarily when clinical examination or basic imaging (X-ray/ultrasound) would suffice, exposing infants to avoidable radiation 4
• Recommending sleep positioning devices that violate safe sleep guidelines 1, 3
• Failing to educate parents that this is a cosmetic issue with excellent spontaneous resolution and no neurological implications 1, 2