Ichthyosis (ick-thee-owe-sis) means 'fish scale', and is the name of a group of genetic skin diseases that cause dry, scaly, thickened skin. 

The skin has many important functions, including physical protection, providing a barrier to keep the skin hydrated (moisturised), protecting against infection, and helping to regulate body temperature.

In normal skin, new skin cells are formed in the deepest layer of skin at the same time as dead cells are shed from the top layer of the skin. In ichthyosis, either the dead cells are shed too slowly, causing a build-up of the top dry layer, or the production of new cells from the lower layers is too slow, allowing too much water to be lost from the skin.

There is no known cure for ichthyosis, but there are treatments available that can help to improve the skin's condition.

Signs and symptoms of ichthyosis

Symptoms of ichthyosis include thick, scaly, dry and cracked skin. If your child has ichthyosis, their skin may appear normal at birth, but then gradually dry out and become scaly. Symptoms usually appear by the age of five years.

• All parts of the body can be affected by ichthyosis, including the face and scalp; however, the bends in the arms and legs are not usually affected. The palms and soles tend to have very thick skin.
  
• Most children with ichthyosis will have a mild form of the disease, and there will a minimal effect on their general health and wellbeing.
  
• Some children will find the condition uncomfortable or embarrassing.
  
• In rare cases, it can be very severe and affect the entire skin surface or cause blisters. In this case, repeated infections, discomfort and sweating problems may occur.

What causes ichthyosis?

Inherited ichthyosis (passed down from parents to children) is usually present at birth or develops in childhood. As a genetic disorder, ichthyosis is not caused by infection and is not contagious (it cannot be caught by others).

Acquired ichythyosis is more common in adults and can be triggered by various conditions or medications.

When to see a doctor

If you are worried about your child's skin, see your GP. The doctor will examine your child's skin and may refer you to see a paediatrician or paediatric dermatologist (skin specialist). A skin biopsy (small sample of skin taken, with an anaesthetic) and genetic test (blood or saliva) may be required for a diagnosis.

If the skin on your child’s feet is causing issues such as thickened skin, pain and cracking, your child may need to see a podiatrist for further management and treatment. 

Treatment for ichthyosis

There are two main types of medications used to treat ichthyosis.

Keratolytics  

Keratolytics help to loosen the scales on the skin and encourage them to come off. They are found in creams that also moisturise the skin. Unfortunately, they can also be irritating, causing redness, stinging, itching or discomfort. The strength of the cream can be changed if any of these symptoms occur.

Examples of keratolytics include:

• lactic acid and salicylic acid 1–5% creams
• ammmonium lactate (e.g. Lanate) 
• hydroxy acid creams (e.g. NeoStrata) 
• urea creams (e.g. Urederm, Eulactol, Calmurid).

Retinoids

In severe cases of ichthyosis, a type of medicine called retinoid (e.g. Neotigason) can be helpful to help get rid of the scale, redness and itch. Retinoids are derived from vitamin A.

Taking high doses of vitamin A can cause dry eyes, lips and nose. Other side effects include nose bleeds, headaches, nausea and high blood cholesterol. If taken during pregnancy, high does of vitamin A can cause birth defects.

Retinoids can only be prescribed by dermatologists and require strict monitoring with regular check-ups and blood tests.

Care at home

If your child has ichthyosis, you may need to spend time each day caring for their skin.

• Moisturisers help improve the condition of skin dryness, replacing the lost moisture and holding it in the skin. They need to be applied regularly, particularly after showering or bathing. Examples of moisturisers include QV cream, Atoderm crème, Kenkay cream, Dermeze, sorbolene and glycerine.
  
• Try to avoid soap, which can dry the skin out even more, and use a soap substitute instead, such as oils and washes (e.g. Hamilton's bath oil, QV bath oil, Dermaveen shower and bath oil, Hamilton wash, QV wash).
  
• If recurrent infections are a problem, adding bleach to your child's baths (along with the bath oil or wash) can help to reduce the bacteria on the skin and prevent further infections. See our fact sheet Skin infections – bleach baths.
  
• For the scalp, shampoos containing salicylic acid or tar can reduce the scaling and help to relieve the itch (e.g. NeoCeutical shampoo and Ducray Kertyol shampoo). After washing, brush the hair to remove scales from the scalp.

Ichthyosis can be distressing for children and their families. Children with the condition may suffer from poor self-esteem, teasing or bullying. Meeting with other young people in a similar situation can be helpful (see For more information below).

Follow-up

See your doctor if your child's skin suddenly gets worse with pain, cracking or oozing/weeping/crusting. Your doctor may prescribe antibiotics to treat any skin infections.

If you are worried about any of your child's treatment, talk to your doctor. If your child is taking oral medications, don't forget to have regular blood tests.

Key points to remember

• Ichthyosis is a group of genetic skin diseases that cause dry, scaly, thickened skin.
• It is usually present at birth or develops in childhood.
  
• Most children with ichthyosis have a mild form of the condition, with few effects on their general health and wellbeing. In some children ichthyosis is very severe and affects the entire skin surface or causes blisters.
  
• Treatment may involve medications and always taking good care of the skin.
  
• If your child is prescribed retinoid medication they will need regular blood tests and check-ups.

For more  information

• See your GP or dermatologist.
• The dermatology department at The Royal Children's Hospital manages children with ichthyosis. Genetic counselling can also be arranged to discuss any aspect of the inheritance and risk to future pregnancies.
• Prenatal testing is available for some types of ichthyosis. Discuss this with your GP or obstetrician.
• Ichthyosis Support Group (UK) 
• Foundation for Ichthyosis & Related Skin Types (US)
• DermNet NZ: Ichthyosis

Developed by The Royal Children's Hospital Dermatology department. We acknowledge the input of RCH consumers and carers.

Reviewed June 2018.

This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit www.rchfoundation.org.au.