Aplasia cutis congenita is a skin disorder in which an infant is born with a patch of skin missing, usually on the scalp. This may occur by itself or be associated with other physical syndromes or disorders. Many forms of aplasia cutis congenita are inherited. The disorder affects both males and females of all ethnic backgrounds and is rare, but exactly how often it occurs is unknown.
A classification system exists for aplasia cutis congenita consisting of 9 groups based on the number and location of the skin defects and the presence or absence of other malformations.
Symptoms
The infant born with aplasia cutis congenita has a patch of skin missing, usually on the scalp (70% of individuals), but it may also occur on the trunk, arms, or legs. There may also be more than one missing patch. The affected area is usually covered with a thin transparent membrane, is well-defined, and is not inflamed.
If aplasia cutis congenita occurs on the scalp, there may be a defect of the skull underneath the missing patch. In this case, there is often distorted hair growth around the patch, known as the hair collar sign.
Diagnosis
Diagnosis of aplasia cutis congenita is made based on the physical appearance of the infant’s skin. No specific laboratory test is needed. Very large scalp defects, especially those with the hair collar sign, should be investigated for possible underlying bone or soft tissue defects.
Treatment
Usually the only treatment required for aplasia cutis congenital is gentle cleansing of the affected area and the application of a silver sulfadiazine or other ointment to prevent the patch from drying out. Most affected areas will heal on their own over several weeks, resulting in the development of a hairless scar. Small bone defects also usually close on their own within the first year of life. Surgical repair is not usually needed unless the missing area of skin is large, or there are several areas on the scalp affected.
Sources:
Crowe, M. (2005). Aplasia cutis congenita. eMedicine, accessed at http://www.emedicine.com/derm/topic32.htm
National Organization for Rare Disorders. Aplasia Cutis Congenita
