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What is Ichthyosis vulgaris and explain in detail?
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,: 486  affecting around 1 in 250 people. For this reason it is known as common ichthyosis. It is usually an autosomal dominant inherited disease (often associated with filaggrin), although a rare non-heritable version called acquired ichthyosis exists.: 560

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. The symptoms will often improve with age, although they may grow more severe again in old age.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 tendons and the calf muscles.

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