What are the most common long-term UVB phototherapy side effects?

Long-term side effects include skin cancer and skin aging (dermatoheliosis). The exact risk of skin cancer has not been determined, but it is greater in patients with fair skin, with a family history of skin cancer, or who use other therapies associated with a risk of producing skin cancer (i.e., PUVA). Patients with prolonged UVB therapy and other risk factors should have periodic skin examinations to detect early skin cancers.