How quickly does narrowband UVB phototherapy relieve itchy skin?

Narrowband UVB uses a carefully controlled band of ultraviolet light to influence inflammation in the skin. It is usually delivered on a schedule set by a dermatology team, rather than as a single quick treatment. Itch may improve before every patch looks clear, and some areas can respond at different speeds. Mild warmth or redness after a session can occur, while an excessive burn is not an expected treatment goal.

Attend sessions according to the prescribed schedule and tell the team about missed appointments, new medicines, or a change in sensitivity to light. Moisturise as advised, avoid extra tanning or unplanned ultraviolet exposure, and do not change the dose yourself. Keep track of itch intensity, sleep disruption, and skin changes; this gives your clinician useful information when adjusting the course.

Report blistering, severe redness, marked soreness, eye discomfort, or a reaction that is worsening after treatment. Contact the team if itch suddenly changes with facial swelling, breathing difficulty, or widespread hives; those symptoms require urgent care. A new rash or a rapidly changing skin area also deserves assessment rather than simply continuing sessions.

Ask which condition is causing the itch, when improvement will be reviewed, how missed sessions affect the schedule, which moisturisers are suitable, and which symptoms should lead you to pause treatment and call.