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Harlequin type ichthyosis
Harlequin type ichthyosis, the most severe form of congenital
ichthyosis, is characterized by a thickening of the keratin layer in
fetal skin. The afflicted child is born with not skin, but massive,
diamond-shaped scales. As well, the eyes, ears, mouth, and other
appendages can be abnormally contracted. The scaly armor limits the
child's movement, and because it is cracked where normal skin would
fold, it is useless for skin's primary function ? protection.
and other contaminants easily pass into the cracks and can cause
The term harlequin comes from both the baby's facial expression and
the diamond-shaped pattern of the scales, which are caused by severe
hyperkeratosis. 17th century entertainers known as jesters, or
harlequins, wore costumes with diamond patterns on them, as well as a
particular style of face paint. The features of the harlequin fetus
mimic this stylized makeup, and their faces are often pulled tight
into grim parodies of a clown's smile.
The disease is also known as harlequin ichthyosis, ichthyosis
congenita, and keratosis diffusa fetalis. Sufferers are known as
harlequin fetuses, harlequin babies, or plain harlequins.
The underlying genetic and biochemical abnormalities that result in
harlequin ichthyosis are not yet completely understood. The disease is
generally thought to be recessive, so a harlequin fetus will only be
born to two parents who carry the gene. The disease can be diagnosed
in the womb by way of fetal skin
In the past, the disorder was invariably fatal, whether due to
dehydration, infection, restricted respiration due to the armored
plating, or other related causes. The most common cause of death is
systemic infection. However, there have been improvements in care
recently, and some children have survived more than the usual few
hours. It is thought that with advancing medical care, within a few
years, harlequin babies will be able to live for up to a decade.
Because of this, and the onset of political correctness, the term
harlequin baby is now preferred over harlequin fetus.
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The features of sufferers are very deformed. The ears may be very
poorly developed or absent entirely, as well with the nose. The
eyelids are severely everted, which leaves the eyes and the area
around them very susceptible to trauma. They often bleed upon birth.
The lips, pulled by the dry skin, are fixed into a vestige of a
clown's smile, which many find extremely disconcerting. Arms, feet,
and fingers are almost always deformed in such a way that they cannot
bend properly, and may be below the normal size. Polydactyly, a
condition in which one has more than the usual number of toes or
fingers, has also been found in these infants.
They are extremely susceptible to changes in temperature due to their
plated skin, which prevents normal heat loss. This can result in
hyperthermia. Their respiration is also restricted by the skin, which
impedes the chest wall from expanding and drawing in enough air. This
can lead to hyperventilation and respiratory failure. Harlequins are
often dehydrated, as their plated skin is not well suited to keeping
The disease has been known since around 1750. More than a hundred
cases have been reported internationally in modern times. Neither
gender nor race seems to make a difference in likelihood of a child
having the disorder. Those with families with a history of severe skin
disorders may have a higher risk of birthing a harlequin child.