Some diseases that cause itching, also known as pruritus, include liver disease, celiac disease, kidney failure, iron deficiency anemia and thyroid problems. Other conditions include cancers, multiple sclerosis, diabetes mellitus, pinched nerves and shingles, according to Mayo Clinic. Skin conditions and rashes, drugs, pregnancy, irritation and allergic reactions also may cause pruritus.
Pruritus may be caused by a number of disorders, but people more at risk include those with diabetes, HIV/AIDS, various types of cancer, pregnant women, the elderly and people with seasonal allergies, hay fever, asthma and eczema, states WebMD. Itchy skin may occur over small areas of the body or over the whole body and may have no other symptoms or may occur along with redness, bumps, spots or blisters, leathery or scaly texture to the skin and dry, cracked skin, notes Mayo Clinic. Prolonged itching and scratching may increase the intensity of the itch resulting in skin injury, infection and scarring.
Treatment of pruritus may include treating an underlying disease, such as kidney disease, iron deficiency and a thyroid problem, light therapy or medications, such as corticosteroid creams, calcineurin inhibitors, oral antihistamines and antidepressants, states Mayo Clinic. Although rare, steroid pills and antibiotics may also be used in the treatment of pruritus, according to WebMD.