Prurigo is a reaction of the skin to itching and other noxious stimuli. It may start off as small bumps on the skin which become persistent and raised as a result of chronic scratching. Sometimes individuals with a personal or family history of hay fever, asthma, and allergies are susceptible to prurigo. In extreme cases, the bumps enlarge at which time the disease is referred to as prurigo nodularis. Patients with prurigo nodularis may have underlying systemic disorders including hepatitis C and sometimes additional testing is required. Treatment of prurigo includes antihistamines, injection of cortisone into the areas, phototherapy and cryotherapy (freezing).