Narrowband UV-B produces superior clinical and histopathological resolution of moderate-to-severe psoriasis in patients compared with broadband UV-B.

OBJECTIVE

To compare the therapeutic effectiveness of daily exposure to narrowband (NB) UV-B vs broadband (BB) UV-B with and without tar.

DESIGN

Half-body exposures to NB UV-B or BB UV-B were given daily for 4 weeks in this comparative treatment study. Narrowband UV-B was delivered from TL-01 fluorescent bulbs and BB UV-B from conventional bulbs in the same phototherapy cabinet. Narrowband UV-B was compared using a paired treatment approach to BB UV-B above the waist and to BB UV-B with tar (Goeckerman treatment) below the waist.

SETTING

General clinical research center of a university hospital inpatient unit.

PATIENTS

Twenty-two patients with moderate-to-severe plaque-type psoriasis completed the study.

MAIN OUTCOME MEASURES

Clinical efficacy was measured weekly using psoriasis severity scoring. Therapeutic outcomes after 4 weeks were compared in paired biopsy samples from treated lesions using objective histopathological measures (quantitative reduction in epidermal acanthosis and keratin 16 expression).

RESULTS

Clinical resolution of psoriasis was achieved on 86% of paired sites treated with NB UV-B vs 73% treated with BB UV-B. Histopathological resolution of epidermal hyperplasia (marked by keratin 16 expression) was achieved in 88% of lesions treated with NB UV-B vs 59% treated with BB UV-B. Epidermal acanthosis was reduced more completely by NB UV-B treatment. Clinical resolution of psoriatic lesions occurred more rapidly following NB UV-B treatment, with some patients achieving complete resolution after 2 to 3 weeks of treatment.

CONCLUSIONS

Narrowband UV-B offers a significant therapeutic advantage over BB UV-B in the treatment of psoriasis, with faster clearing and more complete disease resolution. The erythema response to NB UV-B treatment was significantly more intense and persistent compared with BB UV-B. Considerably more necrotic keratinocytes were observed in histopathological sections of skin treated with NB UV-B after a single 2.0-minimum erythema dose exposure. Treatment should be coupled with obligate minimum erythema dose testing to NB UV-B and close clinical observation during dose increases.