What is Ichthyosis?

The term ichthyosis is derived from the Greek word ichthys, which means fish. Ichthyosis is not one disease but a group of disorders in which there is excess accumulation of epidermal cells resulting in the appearance of scales. Severity ranges from mild, asymptomatic to life threatening. There are a large number of types of ichthyosis; most are extremely rare. This condition tends to be worse in the dry, cold winter months and generally improve in the warmer, more humid months of summer. The most common type of ichthyosis is ichthyosis vulgaris which accounts for almost 95% of cases. Apart from ichthyosis vulgaris all other forms of ichthyosis are very rare. Ichthyosis vulgaris affects about 1:250 individuals. Ichthyosis occurs worldwide and affects people of all races. In addition to this there are many more types but only 3 others will be addressed here. They are lamellar, x-linked, and epidermolytic hyperkeratosis forms of ichthyosis. These conditions are inherited and are based on expression of specific keratin genes which result in the formation of abnormal keratins. Although the signs and symptoms may vary among the different types of ichthyosis, they all show the characteristic dry, rough, scaly skin. Key characteristics of the four main types of inherited ichthyosis are listed in the table below.

Types of
Ichthyosis

Ichthyosis
vulgaris

• At birth skin may appear normal

• Skin gradually becomes dry, rough and scaly, with most signs and symptoms appearing by the age of 5

• Can affect all parts of the body, including the face and scalp. Bends of arms and legs usually spared.

• Palms are excessively lined

• Associated with atopic dermatitis

Lamellar
ichthyosis

• Often called collodion baby as at birth the baby is covered by a thickened collodion-like membrane which is then shed

• Scaling occurs over the whole body, including creases and bends

• May result in drooping lower eyelids (ectropion)

• Prenatal testing in subsequent pregnancies is available

• May be associated with mutation in transglutaminase 1 gene

Epidermolytic hyperkeratosis

• Skin is moist, red, and tender at birth

• Fluid filled blisters may occur which may become infected and give rise to a foul skin odor

• Thick, generalized scaling occurs within a few days

• Biopsy shows epidermolytic hyperkeratosis

X-linked
ichthyosis

• Generalized scaling is present at or shortly after birth

• Scaling is most prominent over the extremities, neck, trunk, and buttocks

• May cause corneal opacities

• Associated with steroid sulphatase deficiency in fibroblasts and elevated plasma cholesterol sulphate

• Only affects males

• May be associated with testicular disease

There is no cure for ichthyosis. The main goal of treatment is to moisturize and exfoliate. This helps prevent dryness, scaling, cracking and build-up of skin. People with ichthyosis need to bathe, moisturize and exfoliate their skin on a daily regular basis. Your dermatologist may prescribe or recommend moisturizing creams and ointments to keep the condition under control. In severe cases they may prescribe oral retinoids such as acitretin or isotretinoin. This can help to reduce scaling. Oral antibiotics may be prescribed if secondary infection occurs. People with ichthyosis have normal lifespan. However they may need to spend several hours each day caring for their skin so they can lead as much of a normal life as possible. At some point during their life people with severe ichthyosis may encounter some of the following problems:

• Overheating: ichthyosis may affect normal temperature control by reducing the ability to sweat

• Limited movement: dry, scaly skin may make it painful to move some parts of the body

• Secondary infection: cracking and splitting of the skin may lead to skin infections and sometimes systemic infections

The following skin care tips may help:

• Apply lotions and creams to wet skin to trap in the moisture (within 3 minutes of showering/bathing)

• Rub gently a pumice stone on wet skin to help remove thickened crusty skin

• Brush washed hair to remove scales from scalp

• Lanolin creams and products containing urea, lactic acid and other alpha hydroxy acids may help to exfoliate and moisturize skin