What is the recommended work-up for a 4-year-old girl with new progressive facial asymmetry?

Work-up for New Progressive Facial Asymmetry in a 4-Year-Old Girl

A 4-year-old with new progressive facial asymmetry requires immediate neuroimaging with brain MRI with contrast and urgent referrals to pediatric neurology and ophthalmology to rule out intracranial pathology, facial nerve disorders, and compensatory strabismus before considering structural craniofacial causes.

Immediate Diagnostic Imaging

• Obtain brain MRI with contrast as the first-line imaging study to evaluate for intracranial mass, tumor affecting the facial nerve, or cerebrovascular pathology 1
• Order 3D-CT maxillofacial scan only after neurological causes are excluded, to assess skeletal discrepancies and soft tissue deficiency if structural asymmetry is confirmed 2

Critical Clinical Assessment

History Taking

• Document exact onset timing and rate of progression of the asymmetry 1
• Assess for associated symptoms including weakness, sensory changes, vision problems, or developmental delays 1
• Review for history of trauma, birth complications, or family history of craniofacial anomalies 3
• Examine old photographs to determine if torticollis or head tilt was present, which may indicate chronic superior oblique muscle palsy 4

Physical Examination Components

Facial Nerve Function:

• Perform complete facial nerve assessment using House-Brackmann scale to evaluate for Bell's palsy or other facial nerve pathology 1

Ophthalmological Assessment:

• Check visual acuity, binocular alignment, and extraocular muscle function 1
• Evaluate for compensatory head posture from strabismus, particularly superior oblique muscle palsy, which can cause secondary facial asymmetry if present since infancy 4
• Perform fundoscopic examination 1

Neurological Examination:

• Complete cranial nerve assessment beyond just facial nerve 1
• Test motor and sensory function throughout 1
• Evaluate cerebellar function 1

Structural Facial Analysis:

• Assess facial asymmetry pattern by evaluating midline vertical alignment through glabella, nasal dorsum, philtrum, and menton 5
• Check for left-right differences in facial width, orbital level, and alar base position 5
• Evaluate for cheek flattening or slanting of midface, which suggests category (f) asymmetry requiring more extensive workup 2

Urgent Specialty Referrals

• Immediate pediatric neurology referral for evaluation of possible intracranial or neurological causes 1
• Immediate pediatric ophthalmology referral for comprehensive eye examination to rule out strabismus with compensatory head posture 1

Differential Diagnosis Priority

The progressive nature in a 4-year-old demands exclusion of:

1. Intracranial pathology (mass, tumor, cerebrovascular event) - most urgent 1
2. Facial nerve disorders (Bell's palsy, facial nerve tumor) 1
3. Strabismus with compensatory head posture causing secondary facial asymmetry 1, 4
4. Congenital muscular torticollis - facial asymmetry is progressive if untreated, especially before age 3 years 6
5. Hemifacial microsomia - demonstrates progressive asymmetry with growth 7

Critical Pitfalls to Avoid

• Do not assume benign structural asymmetry without neuroimaging - new-onset progressive hemifacial asymmetry in a child should be considered potentially serious requiring prompt evaluation 1
• Do not miss compensatory head posture from strabismus - this functional asymmetry can cause true facial asymmetry if present chronically, and resolution may occur if corrected before facial maturation 4
• Do not delay evaluation - facial asymmetry may be the first sign of an intracranial process requiring urgent attention 1
• Distinguish between true anatomical asymmetry and functional asymmetry from compensatory posturing 1

Follow-up Monitoring

• Close monitoring of progression is essential, as conditions like hemifacial microsomia show increasing asymmetry with growth 1, 7
• Repeat imaging may be necessary if symptoms progress or change 1
• If congenital muscular torticollis is diagnosed, early correction should be considered as facial asymmetry is progressive before age 3 years if the contracted sternocleidomastoid is not released 6