PSORIASIS ASSOCIATION RESEARCH REPORT

Title of the research project
Clinical and molecular assessment of photosensitive psoriasis

Grant awarded £51,940

Location of the research University of Manchester, Hope Hospital

Lead researcher Dr L E Rhodes

Reasons for doing the research
Some people find that their psoriasis gets worse when it is exposed to the sun and that it is usually worse in the summer than winter. This research looks at what changes occur in the skin when people with photosensitive psoriasis are exposed to broadband ultraviolet A (UVA) light.

Type of research
Three groups of people were recruited to take part in the study, people with photosensitive psoriasis, non-photosensitive psoriasis and no psoriasis. Healthy skin on the forearm of each subject was exposed to a low dose of broadband UVA and samples of skin were then taken at three standard time intervals following the exposure. Comparative skin samples were also taken from the arm that had not been exposed. The biopsies were assessed for a range of parameters in order to discover what changes had been caused by the light.

Dates the grant awarded 2003 & 2004

Date research presented 2006

Outcomes of the research
The low dose of light used in this study caused inflammation and other changes to the skin of all subjects with photosensitive psoriasis, but had no effect on people in the other two experimental groups. More detailed analysis of skin samples suggested possible molecular reasons for the changes in some subjects.

Conclusions
Low doses of UVA light produce changes in some individuals with photosensitive psoriasis, which are consistent with changes more generally found in the early stages of spreading psoriatic lesions. The results suggest a potential molecular target for treatment of psoriasis in these subjects, and suggest that further study of photosensitive psoriasis may provide a useful model for investigating the mechanisms underlying the condition.

What does this project mean for people with psoriasis?
Photosensitive psoriasis gets little attention from researchers and this study breaks new ground in relation to understanding what happens within the skin of people who suffer from it. Examining the changes that occur in the skin of people with photosensitive psoriasis may also help to illuminate the changes that happen in newly developing psoriasis for all patients with the condition.

Have there been any publications as a result of the research?
None as yet. However, there have been a number of oral presentations at conferences, one of which won first prize for best oral presentation at a meeting of the British Association of Dermatologists.

Glossary
Ultraviolet light: This type of light is not visible to the human eye, but it is part of the spectrum of natural sunlight. It occurs at short wavelengths. In this experiment broadband UVA was used with a wavelength of 320-400 nm.