Narrowband (311-nm) UV-B therapy for small plaque parapsoriasis and early-stage mycosis fungoides

Background: Broadband UV-B phototherapy has been used for many years in the treatment of small plaque parapsoriasis (SPP) and early-stage mycosis fungoides (MF). Our purpose was to investigate the effect on these diseases of narrowband (311-nm) UV-B therapy, which was recently established for the treatment of psoriasis and found to be more effective than broadband UV-B therapy. Observations: Twenty patients (5 women, 15 men; age range, 39-85 years) with histologically confirmed SPP or early-stage MF were enrolled. Six patients had early-stage MF (patch stage), and 14 had SPP. Treatment with 311-nm UV-B was given 3 to 4 times a week for 5 to 10 weeks. In 19 patients, lesions completely cleared after a mean number of 20 treatments (range, 14-29 treatments) and a mean cumulative UV-B dose of 16.3 J/cm(2) (range, 7.4-36.4 J/cm2) within a mean time of 6 weeks (range, 5-10 weeks). Biopsy specimens taken immediately after the end of phototherapy showed only sparse inflammatory infiltrates but no signs of SPP or MF. Relapses at cutaneous sites occurred in all patients within a mean time of 6 months (range, 2-15 months). Conclusions: Narrowband UV-B therapy is an effective short-term treatment modality for clearing SPP and early-stage MF. However, the treatment response did not sustain long-term remission. Further studies are necessary to examine how the clinical response to and follow-up after narrowband UV-B therapy compares with that of established phototherapy modalities in these diseases.