Controlled drug trials in photodermatoses

While clinical drug trials in photodermatoses may be complex because of the fickleness of these disorders in their reproducibility following ultraviolet exposure, such investigations require the same general principles of careful design as those in any other disciplines. The ideal clinical trial in photodermatology is both randomized and double-blind. Precise diagnostic terminology and monitoring of sun exposure must be employed. Polysulphone film badges are the most suitable personal dosimeters to date for these studies. Assessment of itching and discomfort may be reliably performed by the use of a visual analogue scale. Symptoms may also be assessed, but less precisely, by means of a diary record. Only by the use of controlled trials, however, will anecdotal dogma be prevented from inappropriately entering the therapeutic armamentarium of the dermatologist who manages such light sensitive conditions.