A to Z of syndromes

A-Z of syndromes: X-linked ichthyosis

An insight into this genetic disorder occurring in 1 in 6,000 infant males

An insight into this genetic disorder occurring in 1 in 6,000 infant males


X-linked ichthyosis (pictured in a young adult) can present as a minor skin rash. Picture: Science Photo Library

X-linked ichthyosis, as the name suggests, is the inherited presence of an anomaly carried by the X chromosome. An X-linked recessive trait would occur only in males as they only have a single X chromosome and any anomalies carried by the X chromosome will be expressed. The condition is thought to have an incidence of 1:6,000 and it has been described in all races.

The condition has also been called steroid sulfatase (STS) deficiency, harlequin foetus and collodion baby. Ichthyosis comes from the Greek word for fish scales, which it is said to resemble. Ichthyosis can be life threatening, particularly during the neonatal period, or present as a relatively minor skin condition. 

In the X-linked ichthyosis condition the skin cells are produced at a normal rate, but they do not separate normally at the surface of the stratum corneum and are not shed like normal skin. The result is a build-up of scales. The scales of X-linked ichthyosis can cover the entire body, but most cases only cover a small portion of the body. The face, scalp, palms of the hands and soles of the feet can be free from the scales, but the back of the neck is almost always affected.

Infants with X-linked ichthyosis can be born prematurely and appear wrapped in a tight shiny membrane. The membrane can be so tight that the eyelids are pulled into an ectropion. The membrane will crack and peel over several weeks. Other infants may appear normal when they are first born, but the skin abnormalities will almost always show up by their first birthday.

There is no cure for X-linked ichthyosis. The treatment is often conservative with emollient creams forming the mainstay of the child’s management. Steroids may be tried, but are rarely effective, although newer therapies such as retinoid can be used. X-linked ichthyosis frequently improves in the summer.

Case study

It was Maria and her husband’s first baby. Her premature labour was the first indication of a problem. She had steroids to mature the infant’s lungs and agreed to take part in a trial where magnesium sulphate was administered to reduce the risk of cerebral palsy. When her son was born, he was wrapped up and taken away by the midwives and the neonatal team. He was transferred to the neonatal unit.

Maria’s son was almost completely obscured in a high humidity incubator and she wondered if he was going to be blind because of the appearance of his eyes. The neonatal team provided a guarded prognosis explaining that the usual management of prematurity would be more complex because of his skin condition and that his fluid balance and electrolytes would have to be monitored closely.

As the neonatal unit was in a district general hospital the team requested the guidance of a specialist dermatologist from a large children’s hospital and suggested a plan of care to manage his skin. This focused on the liberal application of an emollient, several times a day, maintaining the high humidity environment, thermal management, pain control and minimal handling. His eyes required hourly insertion of an ocular lubricant to prevent keratitis. Because healing places a high metabolic demand on a newborn the specialist dietitian recommended that a long line be placed, and that parenteral nutrition be provided as soon as possible. 

The team’s priorities were prevention of infection and management of his skin, in the anticipation that this would slowly crack and the membrane would be gradually shed. They were also keen to get him off parenteral nutrition and establish enteral feeding.  

Maria was offered the opportunity for expressing and storing her breast milk so that her son could be breastfed once he was able. 

 

Further information


Doreen Crawford is a nurse adviser with consultancy Crawford McKenzie and consultant editor of Nursing Children & Young People

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