Harlequin ichthyosis is the most severe type of ichthyosis, a family of skin conditions in which skin cells turn over too slowly or too quickly. The result is dry, scaly skin. Some kinds of ichthyosis are minor, and you can treat them with a careful skin care routine. Others, like harlequin ichthyosis, are more serious and require significant medical care. Most types of ichthyosis are genetic, and they are lifelong conditions.
A so-called "harlequin fetus" will have symptoms of this rare condition before birth. Babies with harlequin ichthyosis are born with tight, scaled skin all over their bodies. The condition is life-threatening, though improved treatment means that some people with harlequin ichthyosis are living to adulthood.
Experts estimate that harlequin ichthyosis affects one in 500,000 live births. Annually, fewer than ten babies in the U.S. are born with harlequin ichthyosis.
What Are Harlequin Ichthyosis Symptoms?
Babies with harlequin ichthyosis are born with large plate-like patches of dry skin all over their bodies. The skin is so tight that the baby's eyelids and lips will be pulled open, and their fingers and toes may be stuck in curled-up positions.
The tight skin around their torso is a significant issue because it can make it hard for the baby to breathe. Eating is also a challenge, since the baby may have trouble sucking and swallowing. Many babies with harlequin ichthyosis need tube feeding.
What Causes Harlequin Ichthyosis?
Harlequin ichthyosis is an autosomal recessive genetic trait. This is a genetic condition that a baby inherits from their parents. For a baby to have harlequin ichthyosis, they must inherit the genetic trait from both parents.
Each parent will have only one gene for the condition, which means they don't have symptoms themselves. They are carriers of the gene. Symptoms only arise when a baby has two copies of the gene for harlequin ichthyosis.
When two parents have a recessive trait like harlequin ichthyosis, there is a 25% chance that a baby they have will inherit the gene from both of them and have the condition. There is a 50% chance that the baby will only inherit one copy of the gene and be a carrier with no symptoms. There is a 25% chance that the baby will inherit no copies of the gene at all.
Can Babies Survive With Harlequin Ichthyosis?
Harlequin ichthyosis is life-threatening. In addition to difficulties with breathing and eating, babies born with harlequin ichthyosis often face other significant health challenges, including:
- Premature birth
- Low body temperature
- Elevated sodium levels in the blood
- High risk of respiratory infection
- Risk of eye damage due to eyelids not closing
- Risk of hearing problems
The severe scaling that's present at birth will eventually improve. It usually takes several weeks for the scales to loosen up and reveal new, more flexible skin. During this time, babies need to be in a neonatal intensive care unit (NICU) where nurses can monitor their vital signs and respond to all of their needs.
In the past, most babies born with harlequin ichthyosis died within a few days of birth. Advances in neonatal intensive care have improved their chances of survival. However, more than 50% of the babies born with this condition die within a few weeks of birth.
What Is the Treatment for Harlequin Ichthyosis?
Once your baby is released from the NICU, they will need lifelong care for their condition. Their skin will continue to be dry and prone to tightness. They will need extensive daily care to exfoliate dead skin and keep their skin moisturized.
The intense level of care they need will prevent their skin from cracking and and reduce their risk of skin infections. It will also improve their mobility; their skin will otherwise tighten up and restrict movement. Keeping skin pliable also improves blood flow, especially in their hands and feet.
The thick layers of skin prevent children from being able to sweat. You will need to monitor them for signs of overheating. You will also need to make sure they get sufficient nutrition. The high rate of skin growth means that their bodies use more calories than typical children their age.
Your child's skin will probably always look red, as if they have a sunburn. Their skin may also look flaky or scaly, and their hair will be sparse. Their physical development may be delayed, but children with harlequin ichthyosis usually have typical mental capabilities.
Is There Prenatal Testing for Harlequin Ichthyosis?
Scientists have identified the gene responsible for harlequin ichthyosis. If you are concerned that you and your partner are carriers, you can discuss pre-conception genetic testing with your doctor. If you and the co-parent are both carriers, you may want to explore assisted reproductive technology to reduce the risk of a child having harlequin ichthyosis.
There have been some reports of harlequin ichthyosis being identified in prenatal ultrasound. If your doctor suspects your baby has this condition, you may need to have further testing to get a diagnosis.