Overview Of Lamellar Ichthyosis
Lamellar Ichthyosis (LI) is a rare skin condition. It appears at birth and continues throughout life.
Lamellar ichthyosis is a condition that mainly affects the skin. Infants with this condition are typically born with a tight, clear sheath covering their skin called a collodion membrane. This membrane usually dries and peels off during the first few weeks of life, and then it becomes obvious that affected babies have scaly skin and eyelids and lips that are turned outward. People with lamellar ichthyosis typically have large, dark, plate-like scales covering their skin on most of their bodies. Infants with lamellar ichthyosis may develop infections, an excessive loss of fluids (dehydration), and respiratory problems. Affected individuals may also have hair loss (alopecia), abnormally formed fingernails and toenails (nail dystrophy), a decreased ability to sweat (hypohidrosis), an increased sensitivity to heat, and a thickening of the skin on the palms of the hands and soles of the feet (keratoderma). Less frequently, affected individuals have reddened skin (erythema) and joint deformities (contractures).
Commonly Associated With
Collodion baby – lamellar ichthyosis; Ichthyosis congenital; Autosomal recessive congenital ichthyosis – lamellar ichthyosis type
Causes Of Lamellar Ichthyosis
LI is an autosomal recessive disease. This means that the mother and father must both pass one abnormal copy of the disease gene to their child in order for the child to develop the disease.
Mutations in one of many genes can cause lamellar ichthyosis. These genes provide instructions for making proteins that are found in the outermost layer of the skin (the epidermis). The skin abnormalities associated with lamellar ichthyosis disrupt the normal formation of the epidermis, resulting in impaired regulation of body temperature, water retention, and resistance to infections.
Mutations in the TGM1 gene are responsible for approximately 90 percent of cases of lamellar ichthyosis. The TGM1 gene provides instructions for making an enzyme called transglutaminase 1. This enzyme is involved in the formation of the cornified cell envelope, which is a structure that surrounds skin cells and helps form a protective barrier between the body and its environment. TGM1 gene mutations lead to severely reduced or absent enzyme production, which prevents the formation of the cornified cell envelope.
Mutations in other genes associated with lamellar ichthyosis are each responsible for only a small percentage of cases. In some people with lamellar ichthyosis, the cause of the disorder is unknown. Researchers have identified multiple chromosome regions that contain genes that may be associated with lamellar ichthyosis, although the specific genes have not been identified.
Many babies with LI are born with a clear, shiny, waxy layer of skin called a collodion membrane. For this reason, these babies are known as collodion babies. The membrane sheds within the first 2 weeks of life. The skin underneath the membrane is red and scaly. It resembles the surface of a fish.
With LI, the outer layer of skin called the epidermis is not normal and cannot protect the body as the healthy epidermis can.
As a result, a baby with LI may have the following health problems:
- Difficulty in feeding
- Loss of fluid dehydration
- Loss of balance of minerals in the body (electrolyte imbalance)
- Breathing problems
- Body temperature that is not stable
- Skin or body-wide infections
Older children and adults with LI may have these symptoms:
- Very large scales that cover most of the body
- Decreased ability to sweat causing sensitivity to heat
- Hair loss
- Abnormal finger and toenails
- The skin of the palms and soles is thickened
Treatment Of Lamellar Ichthyosis
Collodion babies usually need to stay in the neonatal intensive care unit (NICU). They are placed in a high-humidity incubator. They will need extra feedings. Moisturizers need to be applied to the skin. After the collodion membrane is shed, babies can usually go home.
Lifelong care of the skin involves keeping the skin moist to minimize the thickness of the scales. Measures include:
- Moisturizers applied to the skin
- Medicines called retinoids are taken by mouth in severe cases
- High-humidity environment
- Bathing to loosen scales