What is the appropriate evaluation and management approach for a child with hair on the nasal dorsum, considering their age, sex, and medical history?

Hair on Nasal Dorsum in a Child

A child presenting with hair on the nasal dorsum requires immediate imaging evaluation (MRI preferred) to rule out an underlying dermal sinus tract (DST) or spinal dysraphism, as this is a high-risk cutaneous marker associated with congenital malformations in approximately 70% of cases.

Classification and Risk Stratification

Hypertrichosis (focal tuft of hair) on the nasal dorsum falls into two distinct clinical categories depending on location:

Midline Posterior Spinal Hypertrichosis (High Risk)

• Hypertrichosis is classified as a HIGH-RISK cutaneous marker when located along the posterior spinal midline, often called a "fawn's tail" due to its resemblance to a horse's tail 1
• Present in only 3% of normal neonates but found in almost 70% of children with congenital spinal cord malformations 1
• Most commonly associated with split cord malformations (two-thirds of type I and one-third of type II) 1
• Frequently accompanied by capillary hemangiomas, dimples, subcutaneous masses (lipomas), bone malformations, or teratomas 1

Nasal Dorsum Dermoid Sinus Tract (Requires Evaluation)

• Nasal dermoids are rare developmental anomalies that can present with hair protruding from the nasal dorsum 2, 3
• Mean age at presentation is 29 months, with 89% presenting with naso-glabellar or columellar lesions 2
• Critical distinction: These lesions can have intracranial extension in a significant proportion of cases 2

Immediate Evaluation Algorithm

Step 1: Determine Anatomical Location

• If midline posterior spine: Proceed with spinal imaging evaluation 1
• If nasal dorsum/glabellar region: Proceed with craniofacial imaging evaluation 2

Step 2: Imaging Protocol

• MRI is the preferred imaging modality as it provides superior visualization of neural tissue, intracranial extension, and soft tissue anatomy 1, 2
• CT imaging can identify intraosseous extension into frontonasal bones but is less sensitive for intracranial soft tissue 2
• All patients with suspected nasal dermoids should undergo preoperative imaging before any intervention 2

Step 3: Risk Assessment Based on Imaging Findings

For nasal dermoids, the classification determines surgical approach 2:

• Superficial lesions: Local excision sufficient
• Intraosseous extension (38/45 cases with tracts): Requires open rhinoplasty approach with drilling of frontonasal bones 2
• Intracranial extradural extension (8/45 cases): Requires neurosurgical consultation and craniotomy approach 2
• Intracranial intradural extension (2/45 cases): Requires combined neurosurgical and plastic surgery approach 2

Management Approach

Neurosurgical Consultation Criteria

Obtain immediate neurosurgical consultation if 1, 2:

• Any evidence of intracranial tract or tissue on imaging
• Midline cutaneous anomaly with suspected dermal sinus tract
• Multiple high-risk cutaneous markers present (hypertrichosis + hemangioma + dimple/mass)

Surgical Planning

• Superficial nasal dermoids: External rhinoplasty approach provides best cosmetic outcome with complete excision 4
• Intraosseous extension: Open rhinoplasty with bone drilling for adequate access 2
• Intracranial extension: Small window anterior craniotomy via brow incision is less invasive than traditional bicoronal flap and frontal craniotomy 2

Critical Pitfalls to Avoid

Do NOT Observe Without Imaging

• Never adopt a "wait and see" approach with midline cutaneous markers, as 70% have underlying malformations 1
• Delayed diagnosis can result in bacterial meningitis or intracranial infection if a patent tract exists 1

Do NOT Attempt Excision Without Imaging

• Incomplete excision of nasal dermoids leads to recurrence 2, 3
• Failure to identify intracranial extension preoperatively can result in CSF leak, meningitis, or incomplete resection 2
• Good correlation exists between radiological and surgical findings when proper imaging is obtained 2

Do NOT Confuse with Benign Variants

• Distinguish focal hypertrichosis from diffuse "light hair" commonly seen in normal infants 1
• Transverse nasal creases with milia are benign anatomical variants without underlying pathology 5
• Only 26% of anatomical variations are clinically significant 6

Specialist Referral

Refer to pediatric plastic surgeon or pediatric otolaryngologist for 1:

• Confirmed nasal dermoid on imaging requiring surgical excision
• Congenital malformations of nasal structures
• Any lesion requiring operative intervention

Refer to pediatric neurosurgeon for 1:

• Intracranial extension of dermoid tract
• Suspected spinal dysraphism with high-risk cutaneous markers
• Any midline lesion with potential CNS communication