Congenital aplasia of the skin
Aplasia cutis congenita (ACC) is a disease in which there is a congenital absence of skin, with or without the absence of underlying structures such as bone. Aplasia most commonly affects the scalp, but any location on the body can be affected.
Although unknown, the cause of this disease appears to be multifactorial. The factors that contribute to its appearance are genetic, teratogenic, traumatic and haematic. The absence of skin is evident at birth.
Symptoms
Aplasia cutis congenita is a rare disease with a complex pattern of inheritance. It is a congenital disease, i.e. present from birth. Babies are born with the absence of certain layers of skin, most often – 70% of cases – on the scalp, but also on the trunk and/or arms and legs. The affected area is typically covered with a thin, clear membrane. The skull and/or underlying areas may be visible and be abnormally developed. Aplasia cutis congenita may be the primary disorder or may occur in association with other underlying disorders.
Most individuals with Aplasia Cutis Congenita have no other abnormalities. However, in some rare cases, they may exhibit other physical characteristics including:
- ear abnormalities,
- a form of paralysis that affects one side of the face,
- macrocephaly (an abnormally large head)
- congenital heart anomalies.
Aplasia cutis congenita can also occur as a physical condition characteristic of many other disorders, including:
- Adams-Oliver syndrome, a rare hereditary disorder characterized by the absence of bone in the limbs in areas of the skull and bald ulcerated areas of the overlying scalp. These skull and scalp abnormalities usually heal on their own during the first few months of life, but plastic surgery may be required in some cases. Limb abnormalities can vary in severity.
- aplasia cutis gastrointestinal, a rare disease inherited as an autosomal recessive trait. This disorder is characterized by extensive Aplasia Cutis Congenita and the absence of a normal opening in the tube from below the mouth to the stomach (esophagus), the tube-shaped part of the stomach, and/or the short part of the small intestine which joins the stomach (duodenum). Other symptoms seen in some patients with Aplasia Cutis Congenita-Gastrointestinal may be skin separation and/or low-set ears. This disorder is rapidly progressive.
- Johanson-Blizzard syndrome, is a form of ectodermal dysplasia characterized by defects of the nose, scalp and hair, as well as lack of teeth, deafness, short stature, lack of motor development and malabsorption problems. The most striking feature of this syndrome is the beaked appearance of the nose. Three-quarters of patients have a bump above the posterior fontanelle of the skull at birth that becomes thick and hard as the child grows. Their teeth are peg-shaped and they have fine hair that runs upwards from their foreheads. Patients with Johanson-Blizzard syndrome show marked hearing loss from birth, as well as motor and mental retardation. Bone growth is delayed and intestinal, absorptive and genital defects may be associated.
Cause
Aplasia cutis congenita is a rare disease that can be:
- autosomal dominant
- autosomal recessive.
Let’s see, in simple terms, what this means. Human traits, including classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In dominant disorders, a single copy of the disease gene (received from the mother or father) will be expressed ;dominando; the other normal gene and determining the onset of the disease. The risk of passing the disorder from the affected parent to offspring is 50 percent for each pregnancy, regardless of the resulting baby’s sex.
In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier of the disease, but usually show no symptoms. The risk of transmitting the disease to a couple’s children, both carriers of a recessive disease, is 25 percent. Fifty percent of their children are likely to be carriers of the disease, but generally do not show symptoms of the disorder. 25% of their children may receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for every pregnancy.
Diagnosis
The diagnosis of Aplasia Cutis Congenita is usually obvious at birth due to the characteristic absence of skin affecting the scalp, trunk, arms and/or legs.
Aplasia cutis treatment
Children diagnosed with Aplasia Cutis Congenita should receive a thorough medical evaluation to determine whether this disorder occurs by itself or as a secondary feature of another disorder.
If Aplasia Cutis Congenita occurs on its own, affected children should be monitored for symptoms and physical characteristics associated with this disorder.
Medical treatments of Aplasia Cutis Congenita include measures to prevent drying of the membrane using soothing and mild ointments. Surgical treatments can be aimed at repairing multiple scalp defects.
Katherine Johnson, M.D., is a board-certified obstetrician-gynecologist with clinical expertise in general obstetrics and gynecology, family planning, women’s health, and gynecology.
She is affiliated with the Obstetrics and Gynecology division at an undisclosed healthcare institution and the online platform, Maternicity.com.