What Is Aplasia Cutis?

Aplasia cutis is an exceedingly rare congenital absence of skin, or a type of skin loss that occurs during development of the fetus. It is the most common form of congenital cicatricial alopecia, a type of permanent hair loss that involves simultaneous destruction of the hair follicles and creation of scar tissue. Besides congenital absence of skin and cicatricial alopecia, aplasia cutis is also known as aplasia cutis congenita, cutis aplasia or congenital scars.

The defect that constitutes aplasia cutis usually occurs, about 70 percent of the time, on the scalp as a single circular lesion. There are instances, however, in which there are more than one lesion, and they can be oval or linear in shape. Aplasia cutis can occur in other places in the body, such as the face, trunk and limbs. At birth, the lesions are either completely healed or have a sloughed, reddish appearance.

In 1986, the condition was broken down into classifications according to possible cause. The source of these categorizations was I.J. Frieden’s “Aplasia Cutis Congenita: A Clinical Review and Proposal for Classification,” which was published in the Journal of the American Academy of Dermatology. One of the most popular theories for the cause of such congenital scars is the presence of teratogens, which are defined as agents that hamper normal fetal development. Such culprits are usually pharmaceuticals such as methimazole, which is used to treat thyroid problems; and misoprostol, which is used for artificially or prematurely stimulating childbirth.

Aplasia cutis has also been linked to a rare congenital disorder concerning scalp defects called Adams-Oliver Syndrome (AOS). Despite an incredibly diverse collection of possibilities, there is no unifying reason for the occurrence of aplasia cutis congenita. Compounding this problem of developing a unifying theory is the rarity of such a disorder, as only 500 cases have been reported since it was first described in the mid-18th century.

Treatment of aplasia cutis ranges from mere wound dressing to surgical repair. The latter option is not applied to small or closed congenital scars. Otherwise, surgeons use skin grafts to cover them up. Surgery in some cases, however, presents a complication because of operating at such a sensitive part of the human anatomy, particularly where the brain resides.

Complications arising from aplasia cutis include infection, hemorrhage, meningitis and a rare form of stroke known as sagittal sinus thrombosis. These signs, however, are very uncommon. Moreover, after treatment of cutis aplasia, the prognosis for the patient is typically excellent.