Aplasia cutis congenita is the most common congenital cicatricial alopecia, and is a congenital focal absence of epidermis with or without evidence of other layers of the skin.
Presents in 70% of cases as a solidarity defect on the scalp.
Lesions range 1-2 CM.
Non-inflammatory and well demarcated.
Lesions may be circular or oval.
Old lesions appear in atrophic fibrotic scars with associated alopecia.
Recent lesions appear ulcerated.
Most lesions occur on the vertex of the skull, lateral to midline, but the defects may occur on face, trunk, and limbs.
Skin lesions may involve the epidermis, and upper dermis, and may extend up to the dura.
Most patients have no associated clinical abnormalities.
Can be associated with Johanson-Blizzard syndrome, Adams-Oliver syndrome, trisomy 13, and Wolf-Hirschhorn syndrome.
Has been seen in association with in utero exposure to Methimazole and/or Carbimazole.
This dermatological manifestation has been linked to a deletion in Chromosome 19, and to mutations in the ribosomal GTPase BMS1 gene.
Complications include: bleeding, local infections and meningeal disease.
Most lesions require no therapy and heal on their own.
Larger lesions may require surgical intervention.