Regardless of the underlying cause, itch evokes the behavior of
scratching which increases inflammation and stimulates nerve fibers, leading
to more itching and scratching.Perpetuation of the itch-scratch cycle (see Figure 1) alters the integrity of skin leading to barrier damage.Scratching also causes undesirable changes in skin such as lichenification and prurigo nodule formation. Successful treatment of itch requires
interruption of this cycle.