A review of photodiagnostic investigations over 26 years: experience of the National Scottish Photobiology Service (1989-2015).

Background The Scottish Photobiology Service is the national referral pathway for patients with cutaneous photosensitivity diseases in Scotland. We reviewed the pattern of diagnosis of photosensitivity diseases and investigations performed between 1989 and 2015. Methods and Results Data were collected from the Photodiagnostic Database, annual reports and paper records. The total number of patients assessed each year was stable over the period studied (median 242 [range 231-266]), with most being new patients (median 69 [range 62-73]%). Monochromator phototesting was the most utilised investigation, although the use of provocation testing and photopatch testing has increased. The most common diagnosis was polymorphic light eruption, and there was a trend to increasing diagnosis of photoaggravated atopic eczema. Conclusions The pattern of diagnosis of photosensitivity diseases remains fairly stable in Scotland and we wish to emphasise the importance of this Scottish specialist service for patients with photosensitivity diseases and referrers.