Harlequin Ichthyosis (IH), Autosomal Recessive Manifestation, A Review Article

Iktiosis, discussed specifically in 1808 by William, is a
keratinization disorder in which the skin becomes so dry and scaly
that the skin becomes hard and looks like fish scales...


Introduction
Iktiosis, discussed specifically in 1808 by William, is a keratinization disorder in which the skin becomes so dry and scaly that the skin becomes hard and looks like fish scales. In short, the keratinization process is defective so that the cells in the stratum corneum change shape and number of cells so that they change function. The process of epidermal differentiation is abnormal due to mutations of certain genes in various types of ichthyosis. To date, the number of genes identified and shown to cause ichthyosis in human patients has reached eleven. These genes cause changes in barrier function in the stratum corneum. The most common ichthyosis is ichthyosis vulgaris and has a fairly good prognosis.
The rare and highest severity ichthyosis is harlequin ichthyosis and has a poor prognosis because of its high morbidity rate [1,2].
Iktiosis is a group of skin diseases characterized by scaly skin all over the body. This can be hereditary or acquired. The term ichthyosis or ichthyosis comes from the Greek word ichthys which means "fish", because this condition resembles the scales of a fish.
Iktiosis is a keratinization disorder in which the skin becomes thick, very dry and scaly. This condition was first reported in Indian and Chinese literature since several hundred years BC and was specifically discussed by Willan in 1808. In most cases, this disease is a hereditary disease, but sometimes ichthyosis is an acquired phenomenon, for example associated with lymphoma [2].
The prevalence of hereditary ichthyosis is far more prevalent than acquired ichthyosis. In America, ichthyosis vulgaris (hereditary) has a prevalence of about 1 case in 300 people while acquired ichthyosis is very rare. One study in Berkshire, England, Acquired ichthyosis usually first appears in adulthood, but agerelated systemic diseases do occur in children. Usually affects the age of 3-12 months [1,3]. Iktiosis has various types, but the common ones are Harlequin Ichthyosis (HI). In general, the clinical diagnosis can distinguish the various types of ichthyosis, however, a histopathological diagnostic examination is needed to confirm the diagnosis. Aims of this article is to review HI manifestation and diagnosis.

Discussion
Harlequin Ichthyosis (HI) is an autosomal recessive disorder that rarely occurs in newborns and often causes death within days of birth due to infection or dehydration due to complications.     Skin damage is severely compromised, causing excessive water loss, electrolyte abnormalities, temperature dysregulation, and an increased risk of life-threatening infections. Poor feeding and impaired intestinal absorption are common [7,8] (Figure 3).
Collodion baby is one of the differential diagnoses of harlequin ichthyosis, but it is not difficult to distinguish the two because the clinical picture is milder. Most collodion babies survive to adulthood. In these patients, the differential diagnosis of collodion babies can be ruled out because of the very severe contact with clinical manifestations. Other differential diagnoses include restrictive dermopathy, Conradi's disease, trichothyodystrophy, Gaucher syndrome, Neu-Laxova syndrome, Dorfman-Chanarin syndrome [9] (Figure 4). Currently, the management of hereditary ichthyosis is symptomatic and focuses on hydration, lubrication and keratolysis [3]. Iktiotic skin, although thicker than normal skin, has decreased barrier function and increased transepidermal fluid loss, so that hydration efforts, such as use of moisturizers and long showers, can smoothen skin surface. Areas of hyperkeratosis that are well hydrated can be easier to treat using a mild abrasive agent (sponge, bath wool, stones, etc.). The use of oils while bathing or lubricants such as body lotions, creams, oils, ointments, or vaseline can prolong hydration and smoothness [10].

Conclusion
Harlequin ichthyosis (HI) is an autosomal recessive disorder that resulting in congenital ichthyosis. The underlying genetic disorder in harlequin is a mutation of the lipid transport gene ABCA12 on the chromosome. Acitretin is the most commonly used retinoid for neonates with HI.