How long does narrowband UVB phototherapy take to work for mycosis fungoides?

Mycosis fungoides is a type of cutaneous T-cell lymphoma that can appear as persistent patches or plaques. With suitable skin-limited disease, treatment may gradually reduce redness, scale, thickness, or itch. The visible surface can improve at a different pace from the underlying condition, so your specialist uses repeated skin examinations and your symptoms to guide decisions. This treatment is not appropriate for every stage or pattern of disease.

Keep every appointment where possible and tell the team about missed sessions, new medicines, sun exposure, or changes in lesions. Follow instructions about moisturiser and protective clothing, and avoid extra ultraviolet exposure unless your specialist specifically advises it. Report new lumps, ulcers, bleeding, rapidly changing patches, or symptoms outside the treated areas rather than waiting for the next routine visit.

Contact your treating team promptly if a patch thickens quickly, becomes painful, ulcerates, bleeds, or develops a new lump. Seek urgent help for severe blistering, facial swelling, or breathing difficulty after exposure. Fever or feeling acutely unwell also warrants prompt medical advice, particularly if the skin is broken or draining.

Ask whether your current stage and skin pattern are suitable for narrowband UVB, when response will be reviewed, and which changes should be photographed or reported. Clarify how long the course may continue, how missed visits are handled, and what other options exist if the patches do not settle.