Ichthyosis is a long-term condition that results in persistently thick, dry, “fish-scale” skin. There is no cure, but a daily skincare routine usually keeps the symptoms mild and manageable.

Most people with ichthyosis have inherited a particular faulty gene from their parent. The signs and symptoms of inherited ichthyosis appear at birth or within the first year of life.

This faulty gene affects the rate at which their skin regenerates – either the shedding of old skin cells is too slow, or the skin cells reproduce at a much faster rate than they can shed old skin. Either way, this causes a build-up of rough, scaly skin.

Ichthyosis can also be acquired as an adult, caused by developing certain health conditions.

Ichthyosis vulgaris

The most common type of inherited ichthyosis is ichthyosis vulgaris, which affects about 1 in 250 people. Signs and symptoms include:

• skin may appear normal at birth
• skin gradually becomes dry, rough and scaly, usually before the age of one
• the bends of the elbows and knees and the face are not usually affected
• limbs may develop fine, light grey scales
• skin on the palms of the hands and the soles of the feet may have more lines than normal and be thickened
• the child often also has eczema
• symptoms are more obvious in the winter

Other types of inherited ichthyosis

Other inherited forms of ichthyosis are very rare and include:

• X-linked ichthyosis – this only affects males and includes general scaling, particularly over the limbs, neck and buttocks
• congenital ichthyosiform erythroderma – see below
• harlequin ichthyosis – this is extremely rare, but the scaling is severe and requires intensive care at birth
• syndromes that include ichthyosis – such as Netherton’s syndrome or Sjogren-Larsson syndrome

Congenital ichthyosiform erythroderma

Ichthyosis may develop if a baby is born with a shiny yellow membrane (collodion membrane) that sheds within the first week of life. Once the membrane has shed, one of the following types of ichthyosis can develop:

• non-bullous ichthyosiform erythroderma – inflamed, scaly skin affecting the entire skin surface
• bullous ichthyosiform erythroderma – inflamed, scaly skin with fluid-filled blisters that may become infected and produce a foul-smelling skin odour
• lamellar ichthyosis – where the skin is not as red, but the scales are larger and tighter to the skin

In severe cases of congenital ichthyosiform erythroderma, a child may also have drooping lower eyelids (ectropion), mild hair loss and tight skin on the fingers.

Acquired ichthyosis

Acquired ichthyosis tends to develop in adulthood and is not inherited. It’s usually associated with another disease, such as:

• an underactive thyroid
• kidney disease
• sarcoidosis – a rare disease that causes clumps of cells to form in the organs
• lymphoma – a type of cancer
• HIV infection  

Treatment and outlook

There is no cure for ichthyosis. Treatment involves moisturising and exfoliating the skin every day to prevent dryness, scaling, cracking and the build-up of skin cells.

Some of the more common forms of ichthyosis are mild and will improve in the summertime.

Skincare 

Your dermatologist (skin specialist) will prescribe or recommend suitable emollients, which may be a cream, ointment, lotion or bath oil.

You may find the following advice useful:

• apply emollients to wet skin to trap in the moisture – ideally a few minutes after having a bath or shower
• gently rub wet skin with a pumice stone to remove some of the thickened skin
• brush washed hair to remove scales from your scalp
• other useful exfoliating or moisturising products may include lanolin creams, products containing urea, lactic acid and other alpha hydroxy acids

Your dermatologist may recommend peeling creams, such as salicylic acid, to help exfoliate and moisturise the skin. However, some people may find these products irritate their skin.

Severe cases

People with severe ichthyosis may need to spend several hours a day caring for their skin. They may find they suffer the following problems:

• overheating – because of a reduced ability to sweat
• limited movement – because dry skin makes it too painful to move certain parts of the body
• skin infection – after cracking and splitting of the skin
• impaired hearing or eyesight – this is if skin builds up over the ears or eyes

Antibiotics or antiseptics may be prescribed to treat any skin infections.

People with severe ichthyosis may be prescribed retinoid tablets (vitamin A) such as acitretin or isotretinoin, which reduce the growth of scaly skin but do not improve inflammation or redness. Click on the above links for more information on these medicines.