A new approach to treating skin is appearing in Europe whereby a photosensitising agent is applied to the skin, then the skin is exposed to daylight.
This is a new approach to photodynamic therapy (PDT), with conventional PDT performed in a carefully-controlled clinic setting. Conventional PDT is painful, but effective.
The benefits of daylight PDT are no pain at all and a more convenient method for those with acne, precancerous lesions, or those trying to improve the appearance of the skin. The treatments are becoming very popular in Europe, though research is in its infancy.
To do daylight PDT treatments, a patient must apply sunscreen to block any unwanted effects of the sun on other parts of the body or face, and then apply the solution to the treatment area. Within half an hour, the patient should go out into the daylight for about two hours, whether that’s on a fully cloudy day or a clear blue sky. The temperature should not drop below 10°C.
Most of the research on this treatment is coming out of Europe, where a different form of the main ingredient (aminolevulinic acid) is approved in Europe versus the United States. The sunshine we all get is also different, with sun exposure in Northern European climates quite different to that in in particular the Southern states of the United States and Australia. This makes a direct comparison difficult, with the adverse effects of the treatment going wrong (i.e. too much sunlight) quite drastic, and including burns.
Daylight PDT in Italy
In one Italian study, daylight PDT treatments for a skin condition saw 87 per cent improvement ratings versus conventional PDT which saw 91 per cent improvement ratings. The patients almost all preferred the daylight PDT treatments. There is no pain and inflammation associated with treatments, with the same level of results.
Cure rates of daylight PDT were about the same as conventional PDT with a red light, with a total lack of pain during treatments, which doesn’t happen in conventional treatments.
A Korean study used a much lower dose of a variant of the solution, and clients could apply it and then go about their business. The results were a 58 per cent reduction in inflammatory acne lesions and a 34 per cent decrease in non-inflammatory acne lesions in those who applied the solution every other day with daylight as the only light source.
What’s the controversy?
Some North American dermatologists think daylight PDT is a bad idea because of the risk of sunburn, since the photosensitising gel causes much easier burning than normal skin would see.