Hair collar sign

BY: MOHAMMED ALSAIDAN

Hair collar sign

• Ring-like hypertrichosis consisting of coarser and longer hair surrounding a congenital alopecic lesion on the midline of the scalp.

• A marker of cranial dysraphism, including encephaloceles, meningoceles, Cutaneous meningothelial tumors (heterotropic brain tissue), dermoid cyst , aplasia cutis congenita, Dandy Walker malformation or agenesis of the corpus callosum

• Due to neuroectodermal abnormalities in embryonic development of the cranial neural tube

Hair collar sign

• Encephaloceles and meningoceles communicate directly to the central nervous system by herniation of intracranial structures through a scalp defect

• Heterotropic brain tissue is found with an intact cranium and no connection to the brain

Associations

• Port wine stain

• Subcutaneous hemangioma • the presence of a vascular malformation with a second cutaneous

marker heightens the likelihood of dysraphism

• Cardiac defect ( e.g. VSD)

• Oculoectodermal syndrome : include epibulbar dermoids and other ocular abnormalities, skin hyperpigmentation, congenital heart defects, urinary tract malformations, and neoplasms

• Syndactyly , cleft lip and palate, sclerocornea, scalp epidermal nevus, lipodermoid also have been reported

Approach

• Present at birth ? Growing in size ? Bulging with crying ?

• Thorough physical examination with neurologic evaluation

• Brain MRI

• Screening for spinal abnormalities (spine, spinal cord)

• Genetic counseling ? Translocation t(1;4) (q44;q10).

• Abdominal ultrasound, metabolic screening