Low-dose Ultraviolet A1 Phototherapy for Treating Pityriasis Rosea.

BACKGROUND: UVA1 phototherapy has recently demonstrated high levels of efficacy and tolerability for treating a variety of inflammatory and neoplastic skin diseases.

OBJECTIVE: The purpose of the present study was to assess the clinical efficacy of UVA1 (340~400 nm) phototherapy for treating pityriasis rosea and to assess the course of the disease after treatment.

METHODS: Fifteen patients with extensive pityriasis rosea were treated with low-dose UVA1 phototherapy (starting at 10~20 J/cm(2) and then it was increased to 30 J/cm(2)). The treatments were given 2~3 times a week until complete clearance of lesions was achieved or until there was partial improvement without further amelioration, in spite of 5 additional treatments. The rate of clearing was monitored by estimating the pityriasis rosea severity (PRSS) score and the pruritus score.

RESULTS: The extent of disease (PRSS) in all 15 patients lessened during the study (30.1+/-3.6 vs. 2.0+/-1.6, respectively, p<0.05). The overall reduction of the PRSS showed a significant improvement after the second or third treatment. The pruritus of 12 of 15 patients lessened during the treatment period, and it was unchanged in the remaining 3 patients. The mean previous duration of disease was 11.2+/-4.9 days and this did not interfere with the successful outcome of UVA1 phototherapy.

CONCLUSION: This study shows that UVA1 phototherapy is a useful, well-tolerated treatment option for patients suffering from pityriasis rosea with extensive eruptions and considerable pruritus.