Ichthyosis bullosa of Siemens
Encyclopedia
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. It is a genetic disorder
with no known cure which is estimated to affect about 1 in 500,000 people.
in 1937 from his study of an affected family.
In 1994 the gene causing IBS was discovered and it was also proved in the same year that ichthyosis exfoliativa is the same disease as IBS.
(EHK) but is generally milder than EHK. IBS affects only the upper layers of the epidermis whilst EHK affects the suprabasal layer which is deeper in the
skin.
At birth the baby's skin has a red appearance like a sun burn (erythema). Blistering is usually present at birth and may be extensive or localized depending on the severity of the disease.
Over the first few weeks the redness disappears and is replaced by dry, flaking skin on the arms, legs and around the belly button. Other areas of skin appear normal. The skin is fragile and is prone to blistering (caused by mild trauma or sweating). After a few months hyperkeratosis
develops with a dark grey or brown, ridged appearance on the ankles, knees and elbows. Palms and soles are generally unaffected. A slightly unpleasant, sweet odour may be present.
A distinctive characteristic of IBS which is not present in other forms of ichthyosis is called the "Mauserung phenomenon" (Mauserung is German for "moulting" and was first described by H.W.Siemens). These are small patches of bare, apparently normal skin in the middle of areas of hyperkeratosis.
As the sufferer ages the flaking and blistering should improve. The hyperkeratosis may grow more severe but more localized and is generally only present on flexural folds of the major joints.
A skin biopsy
shows a characteristic damaged layer in the upper spinous level of the skin. Again it may be difficult to distinguish from EHK.
The gene causing IBS is known and so a definite diagnosis can be given by genetic testing
.
on chromosome 12
.
This means an affected person has a 50% chance of passing the condition on to their child. Around half of cases of IBS, however, have no parent with the condition and have the genetic fault due to a spontaneous mutation.
may offer a cure.
Treatments for IBS generally attempt to improve the appearance of the skin and the comfort of the sufferer. This is done by exfoliating and increasing the moisture of the skin. Common treatments include:
Ichthyosis
Ichthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...
. It is also known as bullous congenital ichthyosiform erythroderma of Siemens or ichthyosis exfoliativa. It is a genetic disorder
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
with no known cure which is estimated to affect about 1 in 500,000 people.
History
Ichthyosis bullosa of Siemens (IBS) was first described by the German dermatologist Hermann Werner SiemensHermann Werner Siemens
Hermann Werner Siemens was a German dermatologist who first described many skin diseases and was one of the inventors of the twin study.-Biography:...
in 1937 from his study of an affected family.
In 1994 the gene causing IBS was discovered and it was also proved in the same year that ichthyosis exfoliativa is the same disease as IBS.
Symptoms
IBS has symptoms very similar to epidermolytic hyperkeratosisEpidermolytic 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...
(EHK) but is generally milder than EHK. IBS affects only the upper layers of the epidermis whilst EHK affects the suprabasal layer which is deeper in the
skin.
At birth the baby's skin has a red appearance like a sun burn (erythema). Blistering is usually present at birth and may be extensive or localized depending on the severity of the disease.
Over the first few weeks the redness disappears and is replaced by dry, flaking skin on the arms, legs and around the belly button. Other areas of skin appear normal. The skin is fragile and is prone to blistering (caused by mild trauma or sweating). After a few months hyperkeratosis
Hyperkeratosis
Hyperkeratosis is thickening of the stratum corneum, often associated with a qualitative abnormality of the keratin, and also usually accompanied by an increase also in the granular layer...
develops with a dark grey or brown, ridged appearance on the ankles, knees and elbows. Palms and soles are generally unaffected. A slightly unpleasant, sweet odour may be present.
A distinctive characteristic of IBS which is not present in other forms of ichthyosis is called the "Mauserung phenomenon" (Mauserung is German for "moulting" and was first described by H.W.Siemens). These are small patches of bare, apparently normal skin in the middle of areas of hyperkeratosis.
As the sufferer ages the flaking and blistering should improve. The hyperkeratosis may grow more severe but more localized and is generally only present on flexural folds of the major joints.
Diagnosis
Mild forms of IBS should be diagnosable from appearance and patient history alone. Severe cases of IBS are hard to distinguish from mild EHK.A skin biopsy
Skin biopsy
Skin biopsy is a biopsy technique in which a skin lesion is removed and sent to the pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin...
shows a characteristic damaged layer in the upper spinous level of the skin. Again it may be difficult to distinguish from EHK.
The gene causing IBS is known and so a definite diagnosis can be given by genetic testing
Genetic testing
Genetic testing is among the newest and most sophisticated of techniques used to test for genetic disorders which involves direct examination of the DNA molecule itself. Other genetic tests include biochemical tests for such gene products as enzymes and other proteins and for microscopic...
.
Genetics
IBS is an autosomal dominant genetic condition caused by a mutation in the gene for keratin 2eKeratin 2A
Keratin 2A also known as keratin 2E or keratin 2 is a protein that in humans is encoded by the KRT2A gene.Keratin 2A is a type II cytokeratin. It is found largely in the upper spinous layer of epidermal keratinocytes and mutations in the gene encoding this protein have been associated with...
on chromosome 12
Chromosome 12 (human)
Chromosome 12 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 12 spans about 143 million base pairs and represents between 4 and 4.5 percent of the total DNA in cells.Identifying genes on each chromosome is an active area of genetic...
.
This means an affected person has a 50% chance of passing the condition on to their child. Around half of cases of IBS, however, have no parent with the condition and have the genetic fault due to a spontaneous mutation.
Treatments
There is no cure for IBS but in the future gene therapyGene therapy
Gene therapy is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease. It is a technique for correcting defective genes that are responsible for disease development...
may offer a cure.
Treatments for IBS generally attempt to improve the appearance of the skin and the comfort of the sufferer. This is done by exfoliating and increasing the moisture of the skin. Common treatments include:
- Emolients: moisturisers, petroleum jelly or other emolients are used, often several times a day, to increase the moisture of the skin.
- Baths: long baths (possibly including salt) several times a week are used to soften the skin and allow exfoliation.
- Exfoliating creams: creams containing keratolytics such as urea, salicylic acid and lactic acid may be useful.
- Antiseptic washes: antiseptics may be used to kill bacteria in the skin and prevent odour.
- Retenoids: very severe cases may use oral retinoids to control symptoms but these have many serious side effects including, in the case of IBS, increased blistering.