NB-UVB Phototherapy Incremental Dose Regimen Beneficial for Patients With Psoriasis

UVB therapy hand ultraviolet
Phototherapy dermatosis. Treatment of skin diseases – psoriasis, ekzemy, dermatitis, vitiligo-irradiation with narrow-band ultraviolet.
A 20% incremental dose regimen produces faster response in patients with psoriasis, without increasing the risk for adverse events in III-V skin types.

A 20% incremental dose regimen of narrow-band ultraviolet B (NB-UVB) phototherapy leads to a faster response in patients with psoriasis and skin types III-V without increasing the risk for adverse events, according to study research published in the Journal of the American Academy of Dermatology.

The single-center study included 111 patients with psoriasis and skin types III-V who were randomly assigned to receive different dose increment regimens of NB-UVB 3 times weekly: group 1 (10% dose increment, n = 50); group 2 (20% dose increment, n = 50); and group 3 (30% dose increment, n = 11). Scores on the Psoriasis Area and Severity Index (PASI) and static Physician’s Global Assessment (sPGA) were measured at baseline and after every 5 sessions. The researchers found no statistically significant differences in baseline characteristics in the t3 groups. In group 3, however, 72.7% of patients developed erythema compared with 20.4% in group 1 and 20.8% in group 2.

The percentage of patients who achieved PASI 75 and PASI 90 treatment responses was similar in group 1 and group 2 (PASI 75: 59.2% vs 70.8%, respectively, P = .23; and PASI 90: 24.5% vs 29.2%, respectively, P = .60), the study authors noted. The treatment response, however, was “significantly faster” in patients from group 2 compared with the response in patients in group 1 (P = .026), according to the investigators.

The European S3 guidelines currently recommend NB-UVB dosage increments of 30%, and the American Academy of Dermatology (AAD) guidelines recommend increments of 10%, it was acknowledged. “Although the S3 guidelines recommend an increment of 30%, we do not consider it advisable in skin types III-V,” stated the investigators. “Our findings support previous data suggesting that NB-UVB is highly effective for treatment of plaque psoriasis.

“One interesting finding was that satisfactory treatment response was more likely in those with [a] history of psoriasis remission in summer than in those without such history,” the study authors commented. “Previous studies have reported that sunbathing at the Dead Sea is effective…. We speculate that patients [who] tend to improve in summer may be more sensitive to UVB therapy; thus, such a history could be used as a predictor of response.”


Yu Y, Yi X, Zhang Y, et al. Comparison of different incremental dose regimens of narrow-band ultraviolet B in skin types III-V: A prospective, randomized, single-blind parallel study in patients with psoriasis [published online June 29, 2020]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2020.06.993