Pruritus or itchy skin, often has an underlying cause and so can be relieved once the cause becomes known. Certain diseases, such as liver disease, kidney failure and celiac disease include itchy skin as symptoms. When a disease is the cause, the itch general covers the body. Hives and rashes can also cause skin to itch, and the feeling in those cases is usually limited to the affected area.
Dry or Dehydrated Skin
When the sebaceous glands, the glands that produce the oil that lubricates skin, produce insufficient amounts of sebum, skin becomes dry. On the other hand, when skin does not have enough moisture in it, it becomes dehydrated. Skin requires both moisture and oil to function correctly and to feel soft, smooth and comfortable. Without water and oil, skin can tear, crack and itch. Long-term exposure to environmental factors, whether natural, such as desert climates or artificial, such as air-conditioned rooms, can contribute to dehydrating skin. Taking long hot baths and using soaps that dissolve oil on the skin both contribute to dry skin.
Skin Conditions
Eczema, also called dermatitis, is a condition that causes red, swollen, itchy skin. Over time, skin may thicken and become leathery. Eczema tends to run in families, suggesting a genetic factor and can appear during the first year of life. The Cleveland Clinic notes that people with eczema often have a personal or family history of hay fever, asthma or other allergic conditions. Psoriasis is another skin condition that causes patches of itchy skin. It causes skin cell turnover to speed up, leaving an excess of dead skin cells to build up. These appear as thick, silvery scales, which can crack and weep. Itch and pain are common symptoms.
Irritants
Contact with certain items can irritate skin and cause it to itch. Common irritants include harsh chemicals, soaps, waxes and detergents. These irritating substances wear down the protective oil barrier on the top of skin, causing skin to dry out and itch.
Allergens
Allergens are substances that cause an allergic reaction in a person. When the skin is affected, itchy skin or pruritus often results. The allergy can develop over time, meaning that the first few times of contact do not cause a reaction. Once the allergy becomes established, however, each new contact will cause itching and in some cases, a rash to develop. Common allergens include wool, poison ivy, preservatives and costume jewelry.
Infestations
Lice and mite infestations can cause skin to itch. Lice are tiny, wingless, crawling parasites that feed on human blood and that easily pass from person to person through direct contact. Head lice may also pass through sharing brushes, combs, helmets or other hair or head accessories or equipment, while pubic lice can easily pass from person to person during sexual contact, says the Cleveland Clinic. Lice infestations cause intense itching in the affected areas. Mites are tiny bugs that burrow under skin to feed and lay eggs. They easily pass from person to person through direct contact or through contact with an infested item and their bites cause intense itching, accompanied by a rash.
