Phototherapy with blue (415 nm) and
red (660nm) light in the treatment of acne vulgaris
Papageorgiou P, Katsambas A, Chu A.
Unit of Dermatology, Imperial College of Science, Technology and Medicine,
Hammersmith Hospital, DuCane Road, London W12 0NN, U.K.
In this study we have evaluated the use of blue light (peak at 415 nm)
and a mixed blue and red light (peaks at 415 and 660nm) in the treatment
of acne vulgaris. One hundred and seven patients with mild to moderate
acne vulgaris were randomized into four treatment groups: blue light,
mixed blue and red light, cool white light and 5% benzoyl peroxide cream.
Subjects in the phototherapy groups used portable light sources and irradiation
was carried out daily for 15 min. Comparative assessment between the
three light sources was made in an observer-blinded fashion, but this
could not be achieved for the use of benzoyl peroxide.
Assessments were performed every 4 weeks. After 12 weeks of active treatment
a mean improvement of 76% (95% confidence interval 66-87) in inflammatory
lesions was achieved by the combined blue-red light phototherapy; this
was significantly superior to that achieved by blue light (at weeks 4
and 8 but not week 12), benzoyl peroxide (at weeks 8 and 12) or white
light (at each assessment). The final mean improvement in comedones by
using blue-red light was 58% (95% confidence interval 45-71), again better
than that achieved by the other active treatments used, although the
differences did not reach significant levels. We have found that phototherapy
with mixed blue-red light, probably by combining antibacterial and anti-inflammatory
action, is an effective means of treating acne vulgaris of mild to moderate
severity, with no significant short-term adverse effects.