Major complications are rare but include hemorrhage, secondary local infection and meningitis. There is no racial predilection. There is no sexual predilection. Diagnosis is made on the basis of physical findings indicative of an in utero disruption of skin development. Most lesions occur on the scalp lateral to the midline, but may also occur on the face, trunk, or limbs, sometimes symmetrically.
Lesions are noninflammatory and well-demarcated.
The appearance of lesions varies, depending on when they occur during intrauterine development. Lesions that form early in gestation may heal before delivery and appear as an atrophic, membranous, parchment-like or fibrotic alopecic scar, whereas less mature defects may present as an ulceration of variable depth. With only the epidermis and upper dermis involved, minimal alopecic scarring may result, but deeper defects may extend through the dermis, subcutaneous tissue, and rarely, to periosteum, skull or dura. A complete physical examination should be performed searching for associated physical anomalies or recognizable malformation syndromes. Since this condition is the phenotypic result of more than one disease process, it is very likely that more than one mechanism is involved.