What Is Harlequin Ichthyosis?
Harlequin ichthyosis (HI) is a severe hereditary skin disorder that damages the skin. Newborns with this disease have extraordinarily thick, hard skin covering most of their bodies. The thick, diamond-shaped plates that make up the skin are separated by deep fissures. These skin imperfections alter the appearance of the eyes, nose, mouth, and ears in addition to limiting arm and leg movement. Due to restricted chest movement, babies with harlequin ichthyosis may face breathing issues and respiratory failure. Additionally, eating problems are present in affected infants.
A protective barrier between the body and its surroundings is often formed by the skin. Skin problems linked to harlequin ichthyosis weaken this barrier, making it difficult for affected neonates to manage water loss, maintain a constant body temperature, and combat infections. Infants with harlequin ichthyosis typically have significant fluid loss (dehydration) in the first few weeks of life and develop infections that can be fatal.
What Causes Harlequin Ichthyosis?
Harlequin ichthyosis (HI) is brought on by variations, usually referred to as mutations, in the ABCA12 gene. Instructions for creating a protein deemed necessary for the typical growth of skin cells are provided by the ABCA12 gene. The movement of lipids and enzymes in the epidermis, the top layer of skin, is significantly aided by this protein.
Certain ABCA12 gene variations restrict cells from producing any ABCA12 protein. The synthesis of other variations results in an unusually tiny protein that is incapable of properly transporting lipids. The normal growth of the epidermis is hampered by a loss of functional ABCA12 protein, which causes grave skin defects that are distinctive of harlequin ichthyosis.
How Frequent Is Harlequin Ichthyosis?
Harlequin ichthyosis is extremely unique. One in 500,000 neonates possess harlequin ichthyosis, according to the National Organization of Rare Disorders. Infants of both sexes are equally impacted.
How Is Harlequin Ichthyosis Inherited?
The disease is inherited in an autosomal recessive pattern. An autosomal recessive disorder requires the presence of two copies of a defective gene for the illness or feature to manifest. One copy of the mutated gene is present in each parent of a person with an autosomal recessive disorder, although often, neither parent exhibits the disease's symptoms.
What Are the Signs and Symptoms of Harlequin Ichthyosis?
Some of the common signs and symptoms of HI include the following.
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Infants who have Harlequin ichthyosis have thick, plate-like skin scales. The crimson inner linings of the lips and eyelids turn outward because the skin around the mouth and eyes is so tight that it pulls.
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Due to the skin's stiffness, the infant's chest and abdomen may be substantially constricted, which makes breathing and eating difficult.
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The thick skin actually binds the ears to the head, despite the fact that it may appear as though they are distorted or nonexistent.
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Additionally, neonates with harlequin ichthyosis may have a flat nose, trouble with hearing, multiple respiratory infections, and constrained joint movement.
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Premature birth is prevalent, and it increases the chance of problems for newborns.
How Is Harlequin Ichthyosis Diagnosed?
Fetal skin biopsy, amniocentesis (performed to extract uterine cells and amniotic fluid for evaluation or therapy), chorionic villus biopsy (a method used to take a sample of the placenta between 10 and 13 weeks of pregnancy for genetic assessment), and ultrasound can all be used to diagnose the illness in pregnancy. Skin biopsies taken from any cutaneous site after birth can then be used to confirm the diagnosis since they reveal the typical anomalies in the skin.
How Is Harlequin Ichthyosis Managed Perinatally?
In order to overcome the challenges involved in handling neonates impacted by HI, infants must be admitted to a newborn critical care facility. The team should include experts in a range of disciplines, such as dermatology, neonatology, cosmetic surgery, genetics, ophthalmology, rehabilitation, occupational therapy, dietician, social service providers, and ICU (Intensive Care Unit) physicians and nurses. ICU management is primarily conciliatory. Sepsis and infections caused by bacteria are serious risks for newborns.
Skin barrier loss contributes to an imbalance of electrolytes and the transpiration of water through the epidermis. Physicians are tasked with tracking everyday weight changes, water consumption, and urine output to prevent dehydration. Antibiotics can be used topically for fissures. Pain and discomfort can result from severe fissuring. Acetaminophen, NSAIDs (Non-Steroidal Anti-Inflammatory drugs), or opioids should be used to provide appropriate relief from pain. To maintain an intact airway, neonates who exhibit symptoms of acute respiratory distress need to be intubated.
Eclabium (lips turning outward) brought on by plaque stiffness may result in a rigid mouth and insufficient eating. For adequate consumption of calories, a nasogastric tube will be needed. Neonates are additionally required to take between one and two showers each day in plain water as well as utilize mild emollients to help with the elimination of scales. Due to the possibility of absorption into the body, stay away from strong topical emollients. Systemic retinoids, supplementary treatment, and the incorporation of bland emollients are all part of the highest possible standard of care in Harlequin ichthyosis. Acitretin (a systemic retinoid) accelerates the removal of plates and decreases scaling.
In accordance with physical exam evaluations and adverse effects, acitretin must be calibrated to the smallest dose possible. At six months old, systemic retinoids can be stopped. Topical retinoids with Tazarotene cream is a great choice for treating limb contractions and outward turning of eyelids if oral medication is not tolerated. Children with HI need continual medical attention after the newborn stage, as well as regular subsequent treatment, including speech and language therapy for kids who exhibit behavioral and social problems and physiotherapy and occupational therapy to maximize their range of movements.
Conclusion:
Being a chronic condition, harlequin ichthyosis will constantly require close observation, protection of the skin, and topical medical treatments. But nowadays, children who have been diagnosed with Harlequin ichthyosis receive a far better prognosis compared to those who were born in the past.
