Aplasia cutis congenita is a condition in which there is congenital (present from birth) absence of skin, with or without the absence of underlying structures such as bone. It most commonly affects the scalp, but any location of the body can be affected. While most people with aplasia cutis congenita have no other abnormalities, some people have congenital malformations involving the cardiovascular (heart), gastrointestinal, genitourinary, and central nervous systems. The cause of this condition is unclear and appears to be multifactorial (many different factors appear to play a role); contributing factors may include teratogens, genes, trauma, and compromised blood flow to the skin. 

There is no one cause for all cases of aplasia cutis congenita. The condition is thought to be multifactorial, which means that several factors likely interact to cause the condition. Factors that may contribute include genetic factors; teratogens (exposures during pregnancy that can harm a developing fetus) such as methimazole, carbimazole, misoprostol, and valproic acid; compromised vasculature to the skin; and trauma. Some cases may represent an incomplete or unusual form of a neural tube defect. Familial cases of aplasia cutis congenita have been reported. Cases that appear to be genetic may be inherited in an autosomal dominant or autosomal recessive manner.

Treatment of aplasia cutis congenita varies depending on the condition of the infant. Conservative treatment is preferred. Small areas usually heal on their own over time. Gentle cleansing and application of bland ointments or silver sulfadiazine can help prevent infection. If infection occurs, antibiotics can be used. Recently, a variety of specialized dressing materials have been developed and used. Larger lesions may require surgery. Ultimately, the decision to use medical, surgical, or both forms of therapy depends primarily on the size, depth, and location of the skin defect.

The long-term outlook (prognosis) for people with aplasia cutis congenita is usually excellent. If the condition is associated with other abnormalities or malformations, the prognosis then depends on the nature and severity of the other condition(s).

Major complications of aplasia cutis congenita are rare, but can include hemorrhage, secondary local infection, meningitis, or sagittal sinus thrombosis. Larger affected areas associated with underlying bony defects can cause death due to central nervous system infection, or hemorrhage from the sagittal sinus. Complications can also result from associated abnormalities or malformations, when present.