A randomised half body prospective study of low and medium dose regimens using the 308 nm excimer laser in the treatment of localised psoriasis

Abstract

This study compared two dose-escalation regimens using the 308 nm excimer laser treating localised plaque psoriasis, to determine the optimal regimen. A randomised, left–right body trial was designed including patients aged >18 years with localised plaque psoriasis (<10% body surface area). The standard/low dose regimen started at 70% of the minimal erythema dose (MED), with 20% dose increments. The medium dose regimen commenced at 200% MED, with 25% increments. Patients were treated until disease clearance or a maximum of 36 treatments. Fifteen patients aged 28–55 years completed the study. Psoriasis severity index scores analysed at weeks 0, 6 and 12 showed a significant reduction with each regimen (p < 0.0001). Six patients cleared, seven had significant improvement with uneven clearance of plaques and two failed. Average remission was four months (range 1–12 months). There was a significant reduction in DLQI (p = 0.014). Excimer laser improved psoriasis and reduced DLQI scores, but clearance was incomplete for many patients and remission was short-lived. Adverse effects of pain and blistering were commoner with the medium dose regimen, without any benefit in psoriasis clearance.

Keywords:

• Phototherapy
• ultraviolet B treatment

Acknowledgements

We wish to thank Ms Jackie McCavana and Ms Linda Gray, Medical Physicists for their help with the study and quality assurance programme.

Disclosure statement

The authors report no conflicts of interest.