Longterm carcinogenic effects of daily low emission phototherapy in psoriasis

Several forms of phototherapy are available to psoriasis patients: narrowband
UVB thrice weekly is the standard treatment. Recently we performed a study to
assess the effectivity of a daily low emission phototherapy device (DermaSun
Medical). Preliminary findings during the first few months of treatment showed
no carcinogenic effects.
This treatment modality is used at home, and patients can use this device at
their own volition.

Since, this device has been used in a larger number of patients (over 200) for
several consecutive years. To ascertain the long term effects of treatment with
this home based device an additional study is needed.

To ascertain the amount of UV-damage (p53 activation, apoptosis, thymidine
dimers and γH2AX) is caused by the Dermasun treatment in psoriasis patients.
Total skin check in patients using Dermasun for a prolonged period of time to
screen for (pre-) cancerous skin lesions
Check what actual usage of the Dermasun retrospectively is in patients when it
is readily available to patients on a daily basis

The study is an observational cross-sectional cohort study. Three cohorts of
psoriasis patients will be analysed:

• using Dermasun treatment for a prolonged period of time;

• undergoing conventional narrowband UVB treatment

• not undergoing UV-treatment (yet)

The study has one timepoint where measurement will be performed.

The analysis of the actual use of the Dermasun in patients in cohort is a
retrospective study part.

Patients will be asked to perform one out-patient visit to the dermatology
clinic. Two 4 mm skin biopsies will be taken, preferably from the buttocks
region. Skin biopsies usually heal without scarring.