Aplasia Cutis Congenita

A 4-year-old girl noted to have a scalp lesion on the head since birth. The patient had no other symptoms.

Discussion. Aplasia cutis congenita presents in 70% of cases as a solitary defect on the scalp. The lesions are noninflammatory and well-demarcated, and they range in size from 1 cm to 2 cm. The lesions may be circular or oval; the appearance of the lesion varies depending when they occur in gestation. As in our case, older lesions appear as atrophic fibrotic scars with associated alopecia, while recent lesions appear ulcerated. 

Most lesions occur close to vertex lateral to midline, but similar defect can occur on face, trunk, and limbs, where they are often symmetric. The depth of the lesions may vary—most involve the epidermis and upper dermis, however it may extend deeper up to the dura. Most patients appear to have no other abnormalities; however, aplasia cutis congenita can be found in association with other defects and syndromes. Major complications include bleeding, local infection, and meningitis. 

Differential diagnosis. This condition should be differentiated from focal dermal hypoplasia, which is more common in females, usually linear in distribution, and often associated with other abnormalities. Maternal ingestion of teratogen, methimazole, or intrauterine herpes virus and varicella zoster has been associated with this condition. 

Outcome of the case. Small lesion, like in our case, usually require no treatment and will heal on their own. However, bigger lesions may require surgical intervention. This patient was educated to watch for any infections. 

References: 

1. Behrman RE, Kliegman RM, Jenson HB. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, PA: Elsevier/Saunders; 2000.

2. Deeken JH, Caplan RM. Aplasia cutis congenita. Arch Dermatol. 1970;102(4):386-389.