Clinical Information

What is Narrowband UVB Phototherapy-Light Therapy?

Phototherapy or light therapy involves regular, but brief exposure to ultraviolet (UV) light with specially

designed light emitting equipment. UV light suppresses the immune system and reduces inflammatory

responses by the body. Narrow-band UVB light therapy uses a specific wavelength of 311 to 312 nm

ultraviolet (UV) radiation. This range of UV light is most beneficial for treatment of psoriasis and other

skin conditions including eczema, vitiligo, and lichen planus.

What conditions are treated by UVB phototherapy?


Psoriasis is a common inherited skin disorder, which may vary considerably in extent and severity. Neither phototherapy nor any other available treatment effects a permanent cure.


UVB is suitable for most people with extensive psoriasis. It may not suit those with very fair skin or those whose psoriasis gets worse in sunlight.


Initially, most patients have their treatment three times a week. The first few exposures will be short (less than 5 minutes). The length of exposure is gradually increased, according to the patient's response, up to a maximum of 30 minutes per session. Few patients require such long exposures, most being controlled with shorter times.

Most psoriasis patients will have their psoriasis cleared or much improved after 12 to 24 treatments. At this stage, treatments will usually be discontinued. Even without treatment, the skin may remain clear for some months. However, psoriasis may later flare up again, and further UVB treatment may be necessary.


Those cases of psoriasis which appear to be resistant to UVB may still be helped by another form of ultraviolet treatment called PUVA, or other treatments (e.g. ointments or tablets).



UVB is occasionally used for severe cases of dermatitis, especially atopic eczema. Frequency and dosage of treatment are similar to that used for psoriasis. However, a course of phototherapy may need to be more prolonged than that generally required for psoriasis.



UVB is one of the most effective treatments for vitiligo. Treatments must be cautious as the white skin burns easily. It may take several months to see an improvement.


Other skin conditions

Many other skin conditions have been effectively treated with UVB, including generalized itchprurigocutaneous T-cell lymphomapityriasis lichenoides, and symptomatic dermographism.