Harlequin ichthyosis is a rare congenital disease that affects the skin
Harlequin ichthyosis is a rare congenital disease that affects the skin of nearly 1 in 500,000 people. Around seven babies annually are diagnosed with this condition in the United States.
Earlier, babies with harlequin ichthyosis rarely survived beyond a few days. This was because they were unable to control their body temperature with the thick scabby skin and had difficulty breathing. Thankfully with advances in medical treatments and intensive medical care, the survival years are on a rise. Several children who have survived the condition in their infancy are into their teenage years, and some are even in their twenties.
What exactly is harlequin ichthyosis?
Babies born with harlequin ichthyosis exhibit excessive thickening and hardening of the skin that looks like plates of skin scabs. These plates crack and split apart. The signs and symptoms of the disease include:
Difficulty breathing (death is most often due to breathing problems)
- Difficulty in eating
- Dry eyes
- Flat nose
- Red lips and eyes (everting of the skin causes them to turn inside out)
- Small, swollen hands and feet that lead to restricted joint mobility
- Ears fused to the head that appears as misplaced ears
- Low body temperature
- Hearing impairment
- Frequent respiratory infections
Most of the problems have their roots in the thickening of the skin. Due to the thick skin around the mouth, babies with harlequin ichthyosis face difficulty sucking milk from their mother’s breasts. Hence, they usually need tube feeding.
What causes harlequin ichthyosis?
Harlequin ichthyosis runs in families. The disorder is due to a problem in the gene ABCA12. ABCA12 is responsible for maintaining the skin’s protective barrier against external factors such as microorganisms. Genetic changes (mutations) disrupt this barrier and lead to the characteristic signs of the disorder.
If your baby has harlequin ichthyosis, it is more likely because you and your spouse/partner are carriers of the gene, or one or both of you is/are affected with the signs and symptoms of the disease. Carriers are people who carry the gene but do not show any symptoms.
A higher incidence of harlequin ichthyosis may be encountered in cultures where parental consanguinity is common.
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How is harlequin ichthyosis diagnosed?
Doctors are usually able to diagnose harlequin ichthyosis at birth by looking at the child’s physical features. If someone in the couple’s (parents) family has harlequin ichthyosis or the couple carries a genetic mutation for the condition, prenatal testing can help detect the genetic abnormality in their fetus. This is done by testing the fetal DNA for mutations in ABCA12. Fetal ultrasound that is done in the second trimester and onward can also catch some of the features of the disease.
What is the treatment of harlequin ichthyosis?
Harlequin ichthyosis is a life-threatening condition that needs emergency care under the hands of a team of doctors from various specialties (multidisciplinary team). The treatment is directed at the complications of the disorder such as dehydration and electrolyte imbalances, among others. Oral retinoids (such as acitretin and etretinate) have shown to be of great help in extending the survival of the babies. Doctors use them to improve the outcomes, but these medications are usually reserved for severe cases.
The thick scales of harlequin ichthyosis peel off over several weeks that results in the removal of the skin’s protective barrier and exposes the underlying skin. This makes the skin prone to infections. Local application of antibiotic creams and oral antibiotic pills help treat any skin infections during this period. Heavy moisturizers such as ceramides and petrolatum help prevent water and nutrient loss through the skin. Hence, they are applied religiously to the skin, often several times during the day.