corticosteroids, such as hydrocortisone topical cream; see topical steroid counterirritants, such as mint oil, menthol, or camphor crotamiton (trade name eurax) is an antipruritic agent available as a cream or lotion, often used to treat scabies. its mechanism of action remains unknown. local anesthetics, such as benzocaine topical cream (lanacane) phototherapy is helpful for severe itching, especially if caused by kidney failure. the common type of light used is uvb. sometimes scratching relieves isolated itches, hence the existence of devices such as the back scratcher. often, however, scratching only offers temporary relief and can intensify itching, even causing further damage to the skin, dubbed the "itch-scratch cycle". the mainstay of therapy for dry skin is maintaining adequate skin moisture and topical emollients. no studies have been conducted to investigate the effectiveness of emollient creams, cooling lotions, topical corticosteroids, topical antidepressants, systemic antihistamines, systemic antidepressants, systemic anticonvulsants, and phototherapy on chronic pruritus of unknown origin. however, there are clinical trials currently underway with dupilumab which is thought to alleviate itch by acting on the il-4 receptor on sensory neurons. the effectiveness of therapeutic options for people who are terminally ill with malignant cancer is not known. history in 1660, german physician samuel hafenreffer introduced the definition of pruritus (itch). epidemiology approximately 280 million people globally, 4% of the population, have difficulty with itchiness. this is comparable to the 2–3% of the population who have psoriasis.