How effective is narrowband UVB phototherapy for guttate psoriasis?

Guttate psoriasis often appears as many small, scaly spots across the trunk and limbs. UVB reaches the affected skin and can slow the overactive skin-cell and immune activity that drives scaling. It may be useful when many areas make applying a cream difficult. Spots may fade gradually, while colour changes can remain after active inflammation settles. Phototherapy does not remove a possible trigger, such as a recent throat infection, and it may not be the right choice if the diagnosis is uncertain or the eruption is changing quickly.

A dermatologist sets the starting exposure after considering your skin response, medicines, and history of sun sensitivity. Attend the planned sessions consistently and tell the clinic about redness, tenderness, blistering, or a new medicine. Protect untreated skin and eyes as instructed, and do not add sunbathing or tanning sessions. Moisturiser can reduce scale and dryness, but use it according to the clinic’s timing advice. If guttate psoriasis followed a sore throat or another infection, ask whether that trigger needs assessment.

Contact your dermatologist promptly for blistering, marked pain, severe burning, or redness that does not settle after an exposure. Seek urgent care if the rash becomes widespread with fever, you feel very unwell, or the skin is rapidly peeling. New joint swelling, significant stiffness, or nail changes also deserve review because psoriasis can affect more than the skin.

Ask whether the pattern fits guttate psoriasis, how your response will be measured, which medicines need review before UVB, and what to do if a session causes a reaction.