Affected babies are born in a collodionmembrane, a shiny, waxy-appearing 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 hyperkeratosis. 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 medicine, the term collodion baby applies to newborns who appear to have an extra layer of skin that has a collodion-like quality. It is a descriptive term, not a specific diagnosis or disorder.
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. 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. 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 due to keratolytics. 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.
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 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 that can prevent properblood 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.
Genetics
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 is associated with a deficiency of the enzyme keratinocyte transglutaminase. Genes involved include:
Type
OMIM
Gene
Locus
LI1
TGM1
14
LI2
ABCA12
2q34
LI3
CYP4F22
19p13.12
LI5
?
17p
Diagnosis
Treatments
As with all types of ichthyosis, there is no cure but the symptoms can be relieved.
