Ichthyosis lamellaris
Encyclopedia
Lamellar ichthyosis, also known as ichthyosis lammellaris and nonbullous congenital ichthyosis, is a rare inherited skin disorder, affecting around 1 in 600,000 people.
.
With increasing age, the scaling tends to be concentrated around joints in areas such as the groin, the armpits, the inside of the elbow and the neck. The scales often tile the skin and may resemble fish scales.
, the term collodion baby applies to newborns who appear to have an extra layer of skin
(known as a collodion membrane) that has a collodion
-like quality. It is a descriptive term, not a specific diagnosis or disorder (as such, it is a syndrome).
).
Collodion baby can have severe medical consequences, mainly because the baby can lose heat and fluid through the abnormal skin. This can lead to hypothermia
and dehydration
. Strategies to prevent these problems are the use of emollients or nursing the baby in a humidified incubator. There is also an increased risk of skin infection
and mechanical compression, leading to problems like limb ischemia
. There is also a risk of intoxication by cutaneous absorption of topical products, for example salicylate intoxication (similar to aspirin overdose) due to keratolytic
s.
The condition is not thought to be painful or in itself distressing to the child. Nursing usually takes place in a neonatal intensive care unit
, and good intensive care seems to have improved the prognosis markedly. The collodion membrane should peel off or "shed" 2 to 4 weeks after birth, revealing the underlying skin disorder.
The condition can resemble but is different from harlequin type ichthyosis
.
or ichthyosis-like condition or other rare skin disorder.
Most cases (approximately 75%) of collodion baby will go on to develop a type of autosomal recessive congenital ichthyosis (either lamellar ichthyosis or congenital ichthyosiform erythrodema).
In around 10% of cases the baby sheds this layer of skin and has normal skin for the rest of its life. This is known as self-healing collodion baby.
The remaining 15% of cases are caused by a variety of diseases involving keratinization disorders. Known causes of collodion baby include ichthyosis vulgaris
and trichothiodystrophy. Less well documented causes include Sjögren-Larsson syndrome
, Netherton syndrome
, Gaucher disease type 2, congenital hypothyroidism
, Conradi syndrome, Dorfman-Chanarin syndrome, ketoadipiaciduria, koraxitrachitic syndrome, ichthyosis variegata and palmoplantar keratoderma with anogenital leukokeratosis. Since many of these conditions have an autosomal recessive inheritance pattern, they are rare and can be associated with consanguinity
.
Tests that can be used to find the cause of collodion baby include examination of the hairs, blood test
s and a skin biopsy
.
This condition is an autosomal recessive genetic
disorder, which means the defective gene is located on an autosome
, and both parents must carry one copy of the defective gene in order to have a child born with the disorder. Carriers of a recessive gene usually do not show any signs or symptoms of the disorder.
One form of ichthyosis lamellaris (LI1) is associated with a deficiency of the enzyme keratinocyte transglutaminase
.
Genes involved include:
Eye problems: The eyelids can be pulled down by the tightness of the skin and this can make eyelids (but usually just the lower one) very red and they are prone to drying and irritation.
Constriction bands: Very rarely children with this condition can have tight bands of skin around their fingers or toes (usually at the tips) that can prevent proper blood circulation to the area.
Hair loss: Severe scaling of the skin on the scalp can lead to patchy loss of hair, but this is rarely permanent.
Psychological therapy or support may be required as well.
Presentation
Affected babies are born in a collodion membrane, a shiny waxy outer layer to the skin. This is shed 10–14 days after birth, revealing the main symptom of the disease, extensive scaling of the skin caused by hyperkeratosisHyperkeratosis
Hyperkeratosis is thickening of the stratum corneum, often associated with a qualitative abnormality of the keratin, and also usually accompanied by an increase also in the granular layer...
.
With increasing age, the scaling tends to be concentrated around joints in areas such as the groin, the armpits, the inside of the elbow and the neck. The scales often tile the skin and may resemble fish scales.
Collodion baby
In medicineMedicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, the term collodion baby applies to newborns who appear to have an extra layer of skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
(known as a collodion membrane) that has a collodion
Collodion
Collodion is a flammable, syrupy solution of pyroxylin in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...
-like quality. It is a descriptive term, not a specific diagnosis or disorder (as such, it is a syndrome).
Appearance and treatment at birth
The appearance is often described as a shiny film looking like a layer of vaseline. The eyelids and mouth may have the appearance of being forced open due to the tightness of the skin. There can be associated eversion of the eyelids (ectropionEctropion
Ectropion is a medical condition in which the lower eyelid turns outwards. It is one of the notable aspects of newborns exhibiting congenital Harlequin type ichthyosis, but ectropion can occur due to any weakening of tissue of the lower eyelid. The condition can be repaired surgically...
).
Collodion baby can have severe medical consequences, mainly because the baby can lose heat and fluid through the abnormal skin. This can lead to hypothermia
Hypothermia
Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
and dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
. Strategies to prevent these problems are the use of emollients or nursing the baby in a humidified incubator. There is also an increased risk of skin infection
Skin infection
A skin infection is an infection of the skin. Infection of the skin is distinguished from dermatitis, which is inflammation of the skin, but a skin infection can result in skin inflammation...
and mechanical compression, leading to problems like limb ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
. There is also a risk of intoxication by cutaneous absorption of topical products, for example salicylate intoxication (similar to aspirin overdose) due to keratolytic
Keratolytic
Keratolytic therapy is treatment to remove warts and other lesions in which the epidermis produces excess skin. In this therapy, acid medicine, such as salicylic acid is put on the lesion. Keratolytic therapy thins the skin on and around the lesion. It causes the outer layer of the skin to loosen...
s.
The condition is not thought to be painful or in itself distressing to the child. Nursing usually takes place in a neonatal intensive care unit
Neonatal intensive care unit
A Neonatal Intensive Care Unit —also called a Special Care Nursery, newborn intensive care unit, intensive care nursery , and special care baby unit —is an intensive care unit specializing in the care of ill or premature newborn infants.The problem of premature and congenitally ill infants is not a...
, and good intensive care seems to have improved the prognosis markedly. The collodion membrane should peel off or "shed" 2 to 4 weeks after birth, revealing the underlying skin disorder.
The condition can resemble but is different from harlequin type ichthyosis
Harlequin type ichthyosis
Harlequin-type ichthyosis , a skin disease, is the most severe form of congenital ichthyosis, characterized by a thickening of the keratin layer in fetal human skin...
.
Long term course
The appearance can be caused by several skin diseases, and it is most often not associated with other birth defects. In most cases, the baby develops an ichthyosisIchthyosis
Ichthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...
or ichthyosis-like condition or other rare skin disorder.
Most cases (approximately 75%) of collodion baby will go on to develop a type of autosomal recessive congenital ichthyosis (either lamellar ichthyosis or congenital ichthyosiform erythrodema).
In around 10% of cases the baby sheds this layer of skin and has normal skin for the rest of its life. This is known as self-healing collodion baby.
The remaining 15% of cases are caused by a variety of diseases involving keratinization disorders. Known causes of collodion baby include ichthyosis vulgaris
Ichthyosis vulgaris
Ichthyosis vulgaris is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis, affecting around 1 in 250 people. For this reason it is known as common ichthyosis...
and trichothiodystrophy. Less well documented causes include Sjögren-Larsson syndrome
Sjögren-Larsson syndrome
Sjögren–Larsson syndrome is an autosomal recessive form of ichthyosis apparent at birth.-Causes:It is associated with a deficiency of the enzyme "fatty aldehyde dehydrogenase"...
, Netherton syndrome
Netherton syndrome
Netherton syndrome is a severe, autosomal recessive form of ichthyosis associated with mutations in the SPINK5 gene. It is named after E.W. Netherton.- Characteristics :...
, Gaucher disease type 2, congenital hypothyroidism
Congenital hypothyroidism
Congenital hypothyroidism is a condition of thyroid hormone deficiency present at birth. Approximately 1 in 4000 newborn infants has a severe deficiency of thyroid function, while even more have mild or partial degrees. If untreated for several months after birth, severe congenital hypothyroidism...
, Conradi syndrome, Dorfman-Chanarin syndrome, ketoadipiaciduria, koraxitrachitic syndrome, ichthyosis variegata and palmoplantar keratoderma with anogenital leukokeratosis. Since many of these conditions have an autosomal recessive inheritance pattern, they are rare and can be associated with consanguinity
Consanguinity
Consanguinity refers to the property of being from the same kinship as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person...
.
Tests that can be used to find the cause of collodion baby include examination of the hairs, blood test
Blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....
s and a skin biopsy
Skin biopsy
Skin biopsy is a biopsy technique in which a skin lesion is removed and sent to the pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin...
.
Genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
disorder, which means the defective gene is located on an autosome
Autosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
, and both parents must carry one copy of the defective gene in order to have a child born with the disorder. Carriers of a recessive gene usually do not show any signs or symptoms of the disorder.
One form of ichthyosis lamellaris (LI1) is associated with a deficiency of the enzyme keratinocyte transglutaminase
Keratinocyte transglutaminase
Protein-glutamine gamma-glutamyltransferase K is an enzyme that in humans is encoded by the TGM1 gene.Keratinocyte transglutaminase is a transglutaminase enzyme.-Pathology:...
.
Genes involved include:
| Type | OMIM | Gene | Locus |
|---|---|---|---|
| LI1 | TGM1 | 14 | |
| LI2 | ABCA12 ABCA12 ATP-binding cassette sub-family A member 12 also known as ATP-binding cassette transporter 12 is a protein that in humans is encoded by the ABCA12 gene.... |
2q34 | |
| LI3 | CYP4F22 CYP4F22 CYP4F22 is a protein that in humans is encoded by the CYP4F22 gene.This gene encodes a member of the cytochrome P450 superfamily of enzymes... |
9p13.12 | |
| LI5 | ? | 17p |
Associated medical problems
Overheating: The scaling of the skin prevents normal sweating so hot weather and/or vigorous exercise can cause problems.Eye problems: The eyelids can be pulled down by the tightness of the skin and this can make eyelids (but usually just the lower one) very red and they are prone to drying and irritation.
Constriction bands: Very rarely children with this condition can have tight bands of skin around their fingers or toes (usually at the tips) that can prevent proper blood circulation to the area.
Hair loss: Severe scaling of the skin on the scalp can lead to patchy loss of hair, but this is rarely permanent.
Treatments
As with all types of ichthyosis, there is no cure but the symptoms can be relieved.- Moisturizers
- Prevention of overheating
- Eye drops (to prevent the eyes from becoming dried out)
- Systemic Retinoids (Isotretinoin and acitretin are very effective, but careful monitoring for toxicity is required. Only severe cases may require intermittent therapy.)
Psychological therapy or support may be required as well.
See also
- IchthyosisIchthyosisIchthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...
- Congenital ichthyosiform erythrodema
- Bullous congenital ichthyosiform erythroderma
External links
- F.I.R.S.T. - Foundation for Ichthyosis and Related Skin Types at http://www.scalyskin.org/
- British Ichthyosis Support Group (ISG)