What is the appropriate workup for a 4-year-old with new progressive facial asymmetry?

Workup for New Progressive Facial Asymmetry in a 4-Year-Old

Obtain brain MRI with contrast immediately as the first-line imaging study to exclude intracranial mass, tumor affecting the facial nerve, or cerebrovascular pathology, as new-onset progressive facial asymmetry in a child should be considered a potentially serious finding requiring urgent neurological evaluation. 1, 2

Immediate Diagnostic Imaging

• Brain MRI with contrast is the mandatory initial imaging study to rule out intracranial pathology, which represents the most urgent differential diagnosis in progressive pediatric facial asymmetry 1, 2
• Do not order 3D-CT maxillofacial scan initially—this should only be obtained after neurological causes are excluded to assess skeletal discrepancies 1
• CBCT is not recommended as initial imaging due to unnecessary radiation exposure when MRI is indicated 1

Critical Clinical Assessment Required

Document these specific historical elements:

• Exact onset timing and rate of progression of the asymmetry 1, 2
• Associated symptoms including facial weakness, sensory changes, vision problems, or developmental delays 1, 2
• Birth weight, gestational age, prenatal/perinatal history, and developmental milestones 3
• History of head trauma or relevant systemic diseases 3

Perform complete facial nerve examination:

• Assess facial nerve function using the House-Brackmann scale to evaluate for Bell's palsy or other facial nerve pathology 1, 2
• Complete cranial nerve assessment beyond just facial nerve, testing motor and sensory function throughout 1, 2
• Evaluate cerebellar function 1, 2

Comprehensive ophthalmological assessment:

• Check visual acuity, binocular alignment, and extraocular muscle function 1, 2
• Evaluate for compensatory head posture from strabismus, as this can mimic facial asymmetry 1, 2
• Perform fundoscopic examination 1, 2
• Assess for orbital asymmetry 2

Structural Facial Analysis

Systematic evaluation of asymmetry pattern:

• Assess midline vertical alignment through glabella, nasal dorsum, philtrum, and menton 1, 2
• Check for left-right differences in facial width, orbital level, and alar base position 1, 2
• Evaluate for cheek flattening or slanting of midface, which suggests category (f) asymmetry requiring more extensive workup 1, 4
• Document any dysmorphic features or distinctive facial characteristics unusual for the family 3, 2

Urgent Specialty Referrals

• Immediate pediatric neurology referral for evaluation of possible intracranial or neurological causes 1, 2
• Immediate pediatric ophthalmology referral for comprehensive eye examination to rule out strabismus with compensatory head posture 1, 2

Differential Diagnosis Priority

The most critical conditions to exclude urgently:

1. Intracranial pathology (mass, tumor, cerebrovascular event)—the most urgent diagnosis requiring immediate exclusion 1, 2
2. Facial nerve disorders (Bell's palsy, facial nerve tumor) 1, 2
3. Strabismus with compensatory head posture—can create the illusion of facial asymmetry 1, 2
4. Orbital asymmetry 2

Secondary considerations after neurological causes excluded:

• Hemifacial microsomia—shows increasing asymmetry with growth and requires early intervention 5
• Other congenital syndromes (Treacher Collins, Goldenhar, Parry-Romberg) 6
• Developmental deformities 7

Critical Pitfalls to Avoid

• Never assume benign structural asymmetry without neuroimaging—progressive hemifacial asymmetry may be the first sign of an intracranial process requiring urgent attention 1, 2
• Do not delay evaluation—facial asymmetry can herald serious neurological pathology 1, 2
• Distinguish between true anatomical asymmetry and functional asymmetry from compensatory posturing (e.g., head tilt from strabismus) 1, 2
• Do not order radiation-based imaging (CT, CBCT) before MRI in this clinical scenario 1

Follow-up Monitoring

• Close monitoring of progression is essential, as conditions like hemifacial microsomia demonstrate increasing asymmetry with growth 1, 5
• Repeat imaging may be necessary if symptoms progress or change 1, 2
• If congenital malformations are identified after neurological causes excluded, refer to pediatric plastic surgeon 1