About Ichthyosis




What is Ichthyosis

Ichthyosis is a generic name used to describe continual and widespread scaling of the skin. There at least 30 different types but the most common forms include: Ichthyosis vulgaris, X Linked Ichthyosis and Congenital Ichthyosiform Erythroderma.

Ichtyosis may be inherited, but this is fairly rare, or it may develop during later life. The inherited form generally presents during infancy and usually becomes a lifetime condition. Acquired Ichthyosis can develop at any time possibly due to another medical condition, for instance renal failure.

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.

The symptoms manifest themselves in childhood and can often improve with age, although they may become more severe again in old age.

The condition is not life-threatening; In mild cases the impact on the patient  is generally restricted to mild itching and the social impact of having skin with an unusual appearance, which can have scaly patches on the shins,  fine white scales on the forearms and rough palms.

In severe cases there is a build up of scales all over the body although areas with a high concentration of sweat glands are least affected.  When the build up of scales is acute,  the patient can suffer from prickly heat and severe itching especially  when he or she needs to sweat but cannot as a result of the scales. Various topical treatments are available to "exfoliate" the scales, in particular lotions that contain alpha-hydroxy acids.

Risk factors

The climate can have a large impact on the management of the condition. In a hot humid climates the induced sweating can help to clear the scales and so reduce the itch factor. The opposite is true in cold climates where the low temperatures inhibit sweating and also contribute to the build up of scales.

Air-conditioning and overconsumption of alcohol can also aggravate the skin and increase the number of scales and the risk of itching. 

X-linked Recessive Ichthyosis

This condition occurs in males only and develops in infancy with tan or grey scales on the limbs and across the trunk. It may effect the ears and face and the scales appear to be stuck on like stamps . It varies in its severity and improves in fine or sunny weather. It changes very little with age.

This condition is passed on by a mother  to her son with a 50% risk for each son. The carrier mother shows no evidence of the condition.


Congenital Ichthyosiform Erythroderma

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.