Lamellar ichthyosis (or classical lamellar ichthyosis) is considered one of the five main types of ichthyosis (the others being ichthyosis vulgaris, x-linked ichthyosis, congenital ichthyosiform erythroderma, and epidermolytic hyperkeratosis). It is one of the most severe forms of ichthyosis, and it occurs in approximately 1 in 300,000 births.
In lamellar ichthyosis, the skin cells are produced at a normal rate, but they do not separate normally at the surface of the stratum corneum (the outermost layer of the skin) and are not shed as quickly as they should be. The result is a build-up of scales. The entire body is covered with broad, dark, plate-like scales separated by deep cracks. People with lamellar ichthyosis often have trouble closing their eyes completely because of the tightness of the skin around the eyes and eyelids. In some cases, the skin around the eyes pulls so tightly it causes the eyelids to turn outward exposing the inner red lid and causing continuous irritation. This condition is called ectropion. Some physicians recommend plastic surgery to correct it because if it is left untreated, damage to the cornea can develop leading to impaired vision. People with lamellar ichthyosis may also have thickened nails and hair loss due to the thickness of the scales on their scalp. They may also have reddened skin (erythroderma), thickened skin on the palms of the hands and soles of the feet, and decreased sweating with heat intolerance.
Lamellar ichthyosis is present at birth. Many babies born with lamellar ichthyosis are born as “collodion babies,” so called because they are covered with a clear membrane (the collodion). The collodion is then shed within a few days to a few weeks. Sometimes described as having a shellacked appearance, these newborns have skin, which is taut, dark and split. Often the eyelids and lips are forced open by the tightness of the skin, and there may be contractures around the fingers. Problems with temperature regulation, water loss, secondary infections, and systemic infection can occur in the newborn with lamellar ichthyosis.
One of the causes of lamellar ichthyosis is known. In these people, lamellar ichthyosis is caused by a mutation in the gene for the enzyme Transglutaminase 1, an important enzyme for allowing skin to mature and eventually shed. The gene mutation is transmitted through autosomal recessive inheritance. Individuals must inherit two recessive genes for lamellar ichthyosis to show the disease, one from each parent. Each parent (“carrier”) shows no evidence of lamellar Ichthyosis. (For more information on the genetics of lamellar ichthyosis, request FIRST’s publication, Ichthyosis: The Genetics of its Inheritance).
Lamellar ichthyosis is treated topically with skin barrier repair formulas containing ceramides or cholesterol, moisturizers with petrolatum or lanolin, and mild keratolytics (products containing alpha-hydroxy acids). (For more information on which products contain these ingredients, refer to FIRST’s Skin Care Products List.) Severe lamellar ichthyosis can be treated systemically with oral synthetic retinoids (Accutane, Soriatane). Retinoids are only used in severe cases of lamellar ichthyosis due to their known bone toxicity and other complications.
Because of its severity, lamellar ichthyosis has numerous social and psychological repercussions. People who have this form of ichthyosis and their families need a significant amount of support in dealing with these issues. FIRST can help families with support, information, and resources.
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