What is UVB phototherapy?
UVB phototherapy refers to irradiation with short-wave ultraviolet rays. To treat the whole body, unclothed patients stand in specially designed cabinets equipped with fluorescent tubes.
Broadband UVB is traditionally used, but narrowband UVB phototherapy (311nm) is increasingly provided. Increase the dose of UVB for each exposure (three to five times a week, until the skin condition is cleared, there is no response or the predetermined maximum number of treatments is reached). The purpose is to make the skin slightly pink, but not burn the skin.
What are the adverse reactions of UVB phototherapy?
Sometimes, about 8 hours after treatment, at worst, sunburn will appear. This condition will gradually disappear in the next few days and should be treated with frequent emollients.
The role of UVB is similar to sun exposure. Overexposure contributes to skin aging and dangerous skin cancer.
What diseases can UVB phototherapy treat?
Psoriasis is a common genetic skin disease, and its degree and severity can vary greatly. There is no permanent cure with light therapy or any other treatment available.
UVB is suitable for most people with widespread psoriasis. It may not be suitable for people with very fair skin or people whose psoriasis gets worse in the sun.
Initially, most patients receive treatment three times a week. The first few exposure times are very short (less than 5 minutes). According to the patient's response, the exposure time is gradually increased, up to 30 minutes per treatment course. Few patients need such a long exposure, and most patients can be controlled in a short period of time.
Most patients with psoriasis will clear up or get better after 12 to 24 treatments. At this stage, treatment is usually interrupted. Even without treatment, the skin may remain transparent for several months. However, psoriasis may recur later, and further UVB treatment may be required.
Those cases of psoriasis that seem to be resistant to UVB can still be treated with another type of UV therapy called PUVA or other treatments (for example, ointments or tablets).
UVB is occasionally used for severe dermatitis, especially atopic eczema. The frequency and dosage of treatment are similar to those used for psoriasis. However, the phototherapy process may take longer than the time usually required for psoriasis.
UVB is one of the most effective methods for treating vitiligo. Treatment must be cautious, because white skin burns easily. It may take several months to see improvement.
Other skin conditions
Many other skin diseases are also effectively treated with UVB, including general itching, prurigo, cutaneous T-cell lymphoma, pityriasis lichen and symptomatic dermographism.