Also known as pruritis, itching is one of the most unpleasant sensations that we experience. Some itching is associated with a rash, but other itching can be related to internal conditions such as thyroid abnormalities, liver or kidney conditions, and low iron. Skin infection with scabies is also a cause of chronic itching. An office visit with the dermatologist is recommended to diagnose and treat itching. This evaluation frequently requires laboratory testing.