Affected babies are born in membrane, a shiny waxy outer layer to the skin. This dries out and is shed 10-14 days after birth, revealing the main symptom of the disease, extensive scaling of the skin caused by hyperkertosis. The majority of collodion babies will develop congenital ichthyosiform erythoderma. However, a small number of these babies will have normal skin once the membrane is shed and, therefore, it is not possible to accurately predict the outcome in the early stages.
With 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 palms and soles are sometimes thickened and scaly and the scales often tile the skin resembling fish scales.
Usually the health of the child is normal, but obviously some problems may arise with their appearance when starting school and during teenage years.
The less common form of congenital ichthyosiform erythoderma is Lamellar Ichthyosis. This is different in that the skin is less red but the scaling is larger, perhaps darker and more adherent or stuck down.
These two conditions are passed on by parents with normal skin who both carry the abnormal gene (autosomal recessive) and the risk of a further child being affected is 1 in 4. They can be diagnosed
on a skin biopsy from the foetus taken (between 18 - 20 weeks) halfway through a pregnancy, if the parents which to know but there is no way of preventing them before conception, as the abnormal gene has not yet been identified.