At least two families have been reported in which multiple members have had extensive aplasia cutis congenita of the pretibial lower extremities and dorsal hands and feet. ACC due to teratogens. A few cases of ACC have been linked to intrauterine infection with herpes simplex or varicella-zoster virus, or exposure to methimazole in the treatment of maternal thyrotoxicosis during pregnancy. Imperforate anus has been associated with methimazole exposure during gestation. Reticulolinear ACC of the face and neck is a distinctive cutaneous manifestation in several syndromes linked to Xp22.
Lesions are clean, sharply demarcated, and noninflammatory in appearance.
Over 500 cases have been reported since it was described, but due to significant underreporting of this generally benign disorder, precise frequency is unknown. Small underlying bony defects usually close spontaneously during the first year of life. Surgical repair of large or multiple scalp defects may be considered with excision and primary closure, if feasible, or with the use of tissue expanders and rotation of a flap. Truncal and limb defects, despite large size, usually epithelialize and form atrophic scars, which can later be revised if necessary. Major complications are rare but include hemorrhage, secondary local infection and meningitis.