Bar Code Hair Appearance in Genetic Syndromes
The bar code appearance of hair is seen in Christ Siemens Touraine syndrome (d), also known as hypohidrotic ectodermal dysplasia.
Characteristics of Bar Code Hair Appearance
Bar code hair is a distinctive pattern where hair shows alternating light and dark bands when examined microscopically, resembling a commercial bar code. This pattern is pathognomonic for certain genetic conditions, particularly ectodermal dysplasias.
Christ Siemens Touraine Syndrome (Hypohidrotic Ectodermal Dysplasia)
- Characterized by the classic triad of:
- Hypotrichosis (sparse hair)
- Hypohidrosis (reduced sweating)
- Hypodontia (missing teeth)
- The hair shaft shows distinctive alternating light and dark bands
- Patients typically have fine, sparse, and brittle hair
- Often associated with characteristic facies including:
- Frontal bossing
- Depressed nasal bridge
- Prominent lips
- Periorbital hyperpigmentation
Differential Diagnosis
Clouston Syndrome (Hidrotic Ectodermal Dysplasia)
- Features nail dystrophy and palmoplantar hyperkeratosis
- Hair is typically sparse but does not show the bar code pattern
- Sweating is normal (unlike Christ Siemens Touraine)
LAMB Syndrome
- Lentigines, Atrial myxoma, Mucocutaneous myxomas, Blue nevi
- Hair abnormalities may be present but not the characteristic bar code pattern
- Associated with cardiac manifestations
Cockayne Syndrome
- Characterized by premature aging, photosensitivity, and neurological deterioration
- Hair is typically thin but lacks the bar code appearance
- Associated with growth failure and intellectual disability
Diagnostic Approach
When evaluating patients with suspected ectodermal dysplasia:
- Perform detailed examination of hair shaft under microscopy to identify bar code pattern
- Assess for associated features (dental abnormalities, sweating ability)
- Consider genetic testing for mutations in EDA, EDAR, or EDARADD genes (commonly affected in Christ Siemens Touraine syndrome)
Clinical Significance
Early recognition of the bar code hair pattern is important for:
- Proper diagnosis of the underlying genetic condition
- Appropriate genetic counseling for families
- Implementation of multidisciplinary management including dental care, temperature regulation strategies, and cosmetic interventions
The distinctive bar code hair appearance serves as a valuable diagnostic clue that should prompt evaluation for Christ Siemens Touraine syndrome and appropriate genetic workup.