Ichthyosis vulgaris (also known as "autosomal dominant ichthyosis" and "Ichthyosis simplex") is a skin disorder causing dry, scaly skin. It is the most common form of

ichthyosis Ichthyosis is a family of genetic skin disorders characterized by dry, thickened, scaly skin. The more than 20 types of ichthyosis range in severity of symptoms, outward appearance, underlying genetic cause and mode of inheritance (e.g., dominan ...

,Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . affecting around 1 in 250 people. For this reason it is known as common ichthyosis. It is usually an

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

inherited disease (often associated with

filaggrin Filaggrin (filament aggregating protein) is a filament-associated protein that binds to keratin fibers in epithelial cells. Ten to twelve filaggrin units are post-translationally hydrolyzed from a large profilaggrin precursor protein during termi ...

), although a rare non-heritable version called acquired ichthyosis exists.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. .

Presentation

The symptoms of the inherited form of ichthyosis vulgaris are not usually present at birth but generally develop between three months and five years of age.''Ichthyosis vulgaris''
OMIM (Online Mendelian Inheritance in Man), Johns Hopkins University
eMedicine.com The symptoms will often improve with age, although they may grow more severe again in old age.
MedlinePlus ''Medical Encyclopedia''. The condition is not life-threatening; the impact on the patient, if it is a mild case, is generally restricted to mild itching and the social impact of having skin with an unusual appearance. People with mild cases have symptoms that include scaly patches on the shins, fine white scales on the forearms and upper arms, and rough palms. People with the mildest cases have no symptoms other than faint, tell-tale "mosaic lines" between the

Achilles tendon The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (h ...

s and the calf muscles. 2012 April mosaic lines left calf

Severe cases, although rare, do exist. Severe cases entail the buildup of scales everywhere, with areas of the body that have a concentration of sweat glands being least affected. Areas where the skin rubs against together, such as the armpits, the groin, and the "folded" areas of the elbow and knees, are less affected. Various topical treatments are available to "exfoliate" the scales. These include lotions that contain alpha-hydroxy acids.

Associated conditions

Many people with severe ichthyosis have problems sweating due to the buildup of scales on the skin. This may lead to problems such as " prickly itch", which results from the afflicted skin being unable to sweat due to the buildup of scales, or problems associated with overheating. The majority of people with vulgaris can sweat at least a little. Paradoxically this means most would be more comfortable living in a hot and humid climate. Sweating helps to shed scales, which improves the appearance of the skin and prevents "prickly itch". The dry skin will crack on digits or extremities and create bloody cuts. Skin is painful when inflamed and/or tight. For children and adolescents, psychological concerns may include inconsistent self-image, mood fluctuating due to cyclical outbreaks, tendency to addiction, possibility of social withdrawal when skin is noticeably infected, and preoccupation with appearance. Strong air conditioning and excessive consumption of alcohol can also increase the buildup of scales. Over 50% of people with ichthyosis vulgaris have some type of

atopic Atopy is the tendency to produce an exaggerated immunoglobulin E (IgE) immune response to otherwise harmless substances in the environment. Allergic diseases are clinical manifestations of such inappropriate, atopic responses. Atopy may have a ...

disease such as

allergies Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

eczema Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...

, or

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

.''Ichthyosis vulgaris''
, Foundation for Ichthyosis and Related Skin Types (F.I.R.S.T.) Another common condition associated with ichthyosis vulgaris is

keratosis pilaris Keratosis pilaris (KP; also follicular keratosis, lichen pilaris, or colloquially chicken skin) is a common, autosomal- dominant, genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy, small, goosefle ...

(small bumps mainly appearing on the back of the upper arms).

Genetics

Ichthyosis vulgaris is one of the most common genetic disorders caused by a single gene. The disorder is believed to be caused by mutations to the gene encoding profilaggrin (a protein which is converted to

, which plays a vital role in the structure of the skin).''Ichthyosis Research (2006)''
Foundation for Ichthyosis & Related Skin Types (F.I.R.S.T) Around 10% of the population have some detrimental mutations to the profilaggrin gene that is also linked to

atopic dermatitis Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in puritis, itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thickens o ...

(another skin disorder that is often present with ichthyosis vulgaris). The exact mutation is only known for some cases of ichthyosis vulgaris. It is generally considered to be an

condition, i.e., a single genetic mutation causes the disease and an affected person has a 50% chance of passing the condition on to their child. There is some research indicating it may be semi-dominant. This means that a single mutation would cause a mild case of ichthyosis vulgaris and mutations to both copies of the gene would produce a more severe case.

Diagnosis

References

External links