Harlequin icthyosis is a rare genetic skin disorder seen in new born babies. Harlequin icthyosis is commonly referred to as harlequin baby or harlequin foetus. Infants are born with hard outer skin. The skin is commonly referred to as “coat of armour”. The thick outer skin is covered with diamond shape plates. The diamond shaped plates are separated with deep cracks. These deep cracks can help the bacteria to enter in the body and cause infection. Harlequin icthyosis patient shows visible symptoms like skin abnormalities. These skin abnormalities lead to abnormal shape of eyelids, lips, ears and nose. The babies suffering with harlequin icthyosis experience difficulty in movement of arms and legs. In few cases the babies face difficulty in breathing. The babies suffering with harlequin icthyosis cannot survive for long. There are few exceptional cases where the life span is more. The recent study shows that the age of one of the survivors of harlequin icthyosis is 21 years. Most of the babies die in 3-4 weeks or less after birth. Proper care and diet should be given to harlequin babies for survival and well being. Harlequin icthyosis cases are very rare, 1 in 300000 births are known to have harlequin. Male and female both are equally affected with harlequin icthyosis.
The skin which is the outermost layer of the body acts as barrier to fight with infections and to deal with varied temperatures. The babies suffering with harlequin icthyosis lack this outer protective layer resulting in water loss. The abnormalities in the outer layer make the babies more prone to bacterial or viral infection. These infections can be life threatening. The life threatening infections make the survival of patient difficult in the early days of birth. The advancement in technology helps in treating the harlequin babies. The intensive care units and technology helps in the survival of patients in the early days of birth. The harlequin babies are known to produce more amount of keratin in the skin resulting in the diamond shaped scales. The first cases of harlequin were observed in 1750.
The symptoms are clearly visible in harlequin babies. The major symptoms include:
- The diamond and scaly shaped plates on the body in place of skin.
- The ears are either poorly developed or completely absent.
- The nose is completely absent in few harlequin babies.
- Frequent bleeding from the scales on the body
- Dehydration (water loss) through the diamond shaped platy structure
- Dried eyes
- The eyelids are poorly developed and projected outwards which make the eye and its surrounding are more prone to infections.
- Difficulty in breathing
- Inability to move arms and legs freely
- The lips are pulled back and appears as fish mouth
- Hands and feet are smaller in size and swollen.
- Sodium level is high in the blood of harlequin babies
Harlequin foetus is a hereditary disorder. The harlequin icthyosis babies are born when the same defective gene is produced by both parents. If there is one normal gene and one defective gene then the baby does not show any visible symptoms and in turn acts as a carrier of the disease. Parents carrying defective gene does not show any visible symptoms. Parents act as carrier of the disease.
Harlequin icthyosis is caused due to mutation in the ABCA12 gene present in the human cells. These genes encode a protein which is supposed to carry the epidermal lipids to skin. These epidermal lipids help in the formation of skin layer. The mutations or changes in ABCA12 gene results in absence of transmembrane protein formation. Thus these proteins are unable to carry the lipids to the outer layers of the body. The protein responsible for carrying the fats and lips to the cell organelles is also referred to as ABCA12 protein. The mutation in other gene results in formation of smaller version of proteins. This smaller version of proteins cannot transfer the lipids to the cell organelles. The absence or loss of ABCA12 protein leads to abnormal development of epidermis, resulting in hard and platy structure of skin.
Harlequin icthyosis patients experience more complication in the neonatal period. The major complications include:
- Respiratory compromise – Respiratory compromise results in high risk of respiratory death and respiratory failure leading to death of the patients.
- Sepsis – Sepsis is a condition where the chemicals released in the blood to fight against infection harms its own tissues and cell. It is a life threatening condition caused due to infection.
- Feeding difficulty – The abnormal shape of lips result in difficulty in feeding the baby. Breast milk is known for its nutritious content. But there are no reports proving that breast milk is acting as cure for harlequin babies
- Nasal obstruction – The poor development of nose and other sense organs results in nasal obstruction.
- Hyperthermia – Hyperthermia is condition when the person’s body temperature is above its normal range. Hyperthermia is observed in harlequin babies as the deep cracks are present on the skin.
- Dehydration – Dehydration is a common symptom of harlequin icthyosis. The platy structure with cracks results in frequent loss of water from the body.
- Conjunctivitis – As the eye lids are poorly developed. The eyes become dry in harlequin babies. Eye drops are used frequently to keep the eye moist. The harlequin patients are more prone to infections like conjunctivitis due to the free entry of infective agents in the body.
- Ischemia – The undeveloped organs and breathing problems halt the easy blood flow in the harlequin babies. Ischemia is a condition where there is inadequate blood is supplied to the organs like heart. This inadequate supply of blood can lead to death of the babies.
- Hypocalcaemia – Hypocalcaemia is a condition where low levels of calcium are present in the blood serum of the patient.
Diagnosis and treatment
Harlequin icthyosis can be diagnosed during pregnancy. The medical tests like genetic tests can be done to identify the presence or absence of defective genes. The genetic tests also help in identifying the presence or absence of mutation in ABCA12 gene. Prenatal diagnosis of harlequin icthyosis can be done with ultrasonography. It can also be diagnosed by foetal skin biopsy. Harlequin icthyosis can be cured completely. The babies suffering with harlequin icthyosis need immediate and individual care in the intensive care units.
The following measures can be taken to treat the harlequin patients.
- Intravenous supply of fluids -Dehydration will be more in harlequin patients. Dehydration can be treated by supplying fluids intravenously .Intravenous treatment can also help in providing fluids and nutrient to control the body temperature
- Breathing support- Breathing support is given to the babies who experience difficulty in breathing.
- Monitor Sodium and calcium levels – Frequent monitoring of sodium and calcium levels should be done. The patients show high levels of sodium in the blood. The calcium levels are reduced in the severe stages of harlequin icthyosis.
- Lubricants- Lubricants are used to keep the eyes moist.
- Antibiotics- antibiotics are used to avoid bacterial and viral infections. The patients are more prone to infections in the neonatal stage.
- Retinoid – Retinoid are given to the patients to increase shedding of scales.
- Psychological support- psychological support is required for the patients and attendants during the neonatal period.
- Surgery – Surgery is required in few cases where the sense organs like nose or mouth is completely absent.