Pruritus, or itchy skin, is most commonly caused by rashes or dry skin, according to MayoClinic.com. However, in some cases, the itching sensation occurs not on the surface of the skin, but under it. Pruritus under the skin typically does not respond well to topical treatments such as anti-itch creams and lotions. In these cases, there are typically underlying causes producing the itching sensations.
A healthy liver directs bile to the intestine, where it is used in the processing of food and elimination of waste. However, when the liver becomes diseased, the damage can cause bile to back up in the bloodstream. Bile contains salt compounds that are deposited beneath the surface of the skin. These salt compounds produce intense, chronic itching. According to Dr. James F. Balch, author of "Prescription for Nutritional Healing," cirrhosis is one of the most common types of liver disease. Other liver disorders that can cause pruritus are bile duct paucity, which is characterized by too few bile ducts from the liver to the intestines, biliary atresia, a complete absence of bile ducts.
Celiac disease is a genetic autoimmune disorder in which the body's immune system mistakenly attacks food as it is being digested, and damages the lining of the intestine as a result, according to the No Wheat website. It is typically triggered by overconsumption of wheat, pregnancy or stress. When left untreated, celiac disease can cause a variety of problems, including pancreatic disease, infertility, bone disease and nervous system impairment, notes Dr. Balch. It can also cause intense itching, both on the surface and beneath the skin.
People with kidney failure are often prone to severe itching beneath the skin, according to the National Institutes of Health. Pruritus often worsens during or immediately after dialysis. This is because dialysis prevents the body from removing uremic toxins from the body. Itching may also be caused by elevated levels of the parathyroid hormone, which is common during kidney failure.