Ichthyosis (plural ichthyoses) is a heterogeneous family of at least 28, generalized, mostly
geneticA genetic disorder is an illness caused by abnormalities in genes or chromosomes. While some diseases, such as cancer, are due in part to a genetic disorders, they can also be caused by environmental factors. Most disorders are quite rare and affect one person in every several thousands or millions...
skinThe skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system made up of multiple layers of mesodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, birds...
disordersDermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. The name of this specialty originated in the form of the words dermologie and, a little later, dermatologia...
. All types of ichthyosis have dry, thickened, scaly or flaky skin. In many types the skin is said to resemble the scales on a fish; the word ichthyosis comes from the
Ancient GreekAncient Greek is the historical stage in the development of the Greek language spanning across the Archaic , Classical , and Hellenistic periods of ancient Greece and the ancient world. It is predated in the 2nd millennium BC by Mycenaean Greek...
ιχθύς (
ichthysIchthys or Ikhthus is the ancient and classical Greek word for "fish." In English it refers to a symbol consisting of two intersecting arcs, the ends of the right side extending beyond the meeting point so as to resemble the profile of a fish, said to have been used by early Christians as a secret...
), meaning "fish." The severity of symptoms can vary enormously, from the mildest types such as
ichthyosis vulgarisIchthyosis vulgaris is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis, affecting around 1 in 250 people. For this reason it is known as common ichthyosis...
which may be mistaken for normal dry skin up to life-threatening conditions such as
harlequin type ichthyosisHarlequin-type ichthyosis , a skin disease, is the most severe form of congenital ichthyosis, characterized by a thickening of the keratin layer in fetal human skin...
.
Ichthyosis (plural ichthyoses) is a heterogeneous family of at least 28, generalized, mostly
geneticA genetic disorder is an illness caused by abnormalities in genes or chromosomes. While some diseases, such as cancer, are due in part to a genetic disorders, they can also be caused by environmental factors. Most disorders are quite rare and affect one person in every several thousands or millions...
skinThe skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system made up of multiple layers of mesodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, birds...
disordersDermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. The name of this specialty originated in the form of the words dermologie and, a little later, dermatologia...
. All types of ichthyosis have dry, thickened, scaly or flaky skin. In many types the skin is said to resemble the scales on a fish; the word ichthyosis comes from the
Ancient GreekAncient Greek is the historical stage in the development of the Greek language spanning across the Archaic , Classical , and Hellenistic periods of ancient Greece and the ancient world. It is predated in the 2nd millennium BC by Mycenaean Greek...
ιχθύς (
ichthysIchthys or Ikhthus is the ancient and classical Greek word for "fish." In English it refers to a symbol consisting of two intersecting arcs, the ends of the right side extending beyond the meeting point so as to resemble the profile of a fish, said to have been used by early Christians as a secret...
), meaning "fish." The severity of symptoms can vary enormously, from the mildest types such as
ichthyosis vulgarisIchthyosis vulgaris is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis, affecting around 1 in 250 people. For this reason it is known as common ichthyosis...
which may be mistaken for normal dry skin up to life-threatening conditions such as
harlequin type ichthyosisHarlequin-type ichthyosis , a skin disease, is the most severe form of congenital ichthyosis, characterized by a thickening of the keratin layer in fetal human skin...
. The most common type of ichthyosis is
ichthyosis vulgarisIchthyosis vulgaris is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis, affecting around 1 in 250 people. For this reason it is known as common ichthyosis...
, accounting for more than 95% of cases.
Types
There are many types of ichthyosis and an exact diagnosis may be difficult. Types of ichthyosis are classified by their appearance and their genetic cause. Ichthyoses caused by the same gene can vary considerably in severity and symptoms. Some ichthyoses don't appear to fit exactly into any one type. Also different genes can produce ichthyosis with similar symptoms. The most common or well-known types are as follows:
Genetic ichthyoses
- Ichthyosis vulgaris
Ichthyosis vulgaris is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis, affecting around 1 in 250 people. For this reason it is known as common ichthyosis...
- X-linked ichthyosis
X-linked ichthyosis is a skin condition caused by the hereditary deficiency of the steroid sulfatase enzyme that affects 1 in 2000 to 1 in 6000 males. XLI manifests with dry, scaly skin and is due to deletions or mutations in the STS gene...
- Congenital ichthyosiform erythroderma
Congenital Ichthyosiform Erythroderma , also known as Nonbullous congenital ichthyosiform erythroderma is a rare type the ichthyosis family of skin diseases which occurs in 1 in 200,000 to 300,000 births.-Symptoms:...
(nbCIE)
- Epidermolytic hyperkeratosis
Epidermolytic hyperkeratosis, is a rare skin disease in the ichthyosis family affecting around 1 in 250,000 people.It involves the clumping of keratin filaments.-Presentation:At birth, affected babies are called "enfant...
(bullous ichthyosis, bCIE)
- Harlequin type ichthyosis
Harlequin-type ichthyosis , a skin disease, is the most severe form of congenital ichthyosis, characterized by a thickening of the keratin layer in fetal human skin...
- Ichthyosis bullosa of Siemens
Ichthyosis bullosa of Siemens is a rare skin disorder which is a type of familial, autosomal dominant ichthyosis. It is also known as bullous congenital ichthyosiform erythroderma of Siemens or ichthyosis exfoliativa...
- Ichthyosis hystrix
The term ichthyosis hysterix is used to describe several rare skin disorders in the ichthyosis family of skin disorders characterized by massive hyperkeratosis with an appearance like spiny scales. This term is also used to refer to a type of epidermal nevi with extensive bilateral distribution...
- Ichthyosis lamellaris
Ichthyosis lammellaris, also known as lamellar ichthyosis and nonbullous congenital ichthyosis, is a rare inherited skin disorder, affecting around 1 in 600,000 people.-Presentation:...
(lamellar ichthyosis)
Ichthyoses with additional characteristics
- Carvajal syndrome
Carvajal syndrome is a cutaneous condition, a form of ichthyosis, inherited in an autosomal recessive fashion, and due to a defect in desmoplakin....
- CHILD Syndrome
Congenital hemidysplasia with ichthyosiform erythroderma and limb defects is a genetic disorder with onset at birth seen almost exclusively in females...
- Conradi-Hünermann syndrome
- Darier's disease
Darier's disease is a genetic disorder discovered by French dermatologist Ferdinand-Jean Darier. Darier's is characterized by dark crusty patches on the skin, sometimes containing pus...
- Erythrokeratodermia variabilis
Erythrokeratodermia variabilis is a rare autosomal dominant disorder that usually presents at birth or during the first year of life...
(Erythrokeratodermia figurata variabilis, Mendes da Costa type erythrokeratodermia)
- IFAP syndrome
IFAP syndrome is an extremely rare genetic syndrome. It is also known as Ichthyosis follicularis, alopecia, and photophobia syndrome or simply ichthyosis follicularis...
(Ichthyosis follicularis)
- Keratitis-ichthyosis-deafness syndrome
Keratitis–ichthyosis–deafness syndrome presents at birth/infancy and is characterized by pregressive corneal opacification, either mild generalized hyperkeratosis or discrete erythematous plaques, and neurosensory deafness.It is caused by a mutation...
(Senter syndrome)
- Netherton syndrome
Netherton syndrome is a severe, autosomal recessive form of ichthyosis associated with SPINK5.- Presentation :Most babies who have it are "scalded-looking" at birth and are very slow to gain weight all through their life but especially in the first year. As a result they may well be kept in...
- Neutral lipid storage disease
Neutral lipid storage disease is an autosomal recessive disorder characterized by accumulation of triglycerides in the cytoplasm of leukocytes, muscle, liver, fibroblasts, and other tissues....
(Dorfman-Chanarin syndrome)
- Refsum's disease
Refsum's disease , named after Norwegian neurologist Sigvald Bernhard Refsum , is a neurological disease that results in the malformation of myelin sheaths around nerve cells...
- Rud syndrome
Rud syndrome is a poorly characterized disorder, probably of recessive inheritance, that includes epilepsy, mental retardation, infantilism, congenital ichthyosis, and retinitis pigmentosa....
- Sjögren-Larsson syndrome
Sjögren–Larsson syndrome is an autosomal recessive form of ichthyosis apparent at birth.-Causes:It is associated with a deficiency of the enzyme "fatty aldehyde dehydrogenase"...
- Tay syndrome (IBIDS syndrome, Trichothiodystrophy)
Diagnosis
A physician often can diagnose ichthyosis by looking at the skin. A family history is very useful. In some cases, a skin biopsy is done to help to confirm the diagnosis. In a biopsy, a small piece of skin is removed and examined under a microscope. In some instances, genetic testing may be helpful in making a diagnosis.
Ichthyosis is not more or less common in any ethnic group. As of now, there is no way to prevent ichthyosis since it is often of a genetic nature.
Treatments
Treatments for ichthyosis often take the form of topical application of creams and
emollientEmollients are substances that soften and soothe the skin. They are used to correct dryness and scaling of the skin. They are a key component in the manufacture of lipstick, lotions, and other cosmetic products....
oils, in an attempt to hydrate the skin.
RetinoidThe retinoids are a class of chemical compounds that are related chemically to vitamin A. Retinoids are used in medicine, primarily due to the way they regulate epithelial cell growth....
s are also used for some conditions. Exposure to sunlight may improve or worsen the condition.
There can be ocular manifestations of ichthyosis, such as corneal and ocular surface diseases. Vascularizing keratitis, which is more commonly found in congenital keratitis-ichythosis-deafness (KID), may worsen with isotretinoin therapy.
Ichthyosis in animals
Ichthyosis or ichthyosis-like diseases exist for several types of animals, including cattle, chickens, llamas, mice, and dogs. Ichthyosis of varying severity is well-documented in some popular
breedsDog breeds are groups of closely related and visibly similar domestic dogs, which are all of the subspecies Canis lupus familiaris, having characteristic traits that are selected and maintained by humans, bred from a known foundation stock....
of domestic
dogThe dog is a domesticated form of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history...
s. The most common breeds to have ichthyosis are
Golden retrieverThe Golden Retriever is a breed of dog, historically developed as a gundog to retrieve shot waterfowl and upland game during hunting. As such they were bred to have a soft mouth to retrieve game undamaged and an instinctive love of water...
s,
American bulldogThe American Bulldog is a breed of domestic dog . Though larger in size, they are the closest surviving relative of the Old English Bulldog, because they were not altered to as great an extent while in America as their European cousins...
s,
Jack Russell terrierThe Jack Russell Terrier is a small, principally white-bodied, smooth- or rough-coated terrier that has its origins in fox hunting. The name "Jack Russell" has been used over the years to describe a wide array of small white terriers, but now after a drawn-out legal battle, the JRTCA and its...
s, and
Cairn terrierThe Cairn Terrier is one of the oldest terrier breeds, originating in the Scottish Highlands and recognized as one of Scotland's earliest working dogs, used for hunting burrowing prey among the cairns....
s.
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