Do I need to worry about indirect sun exposure after having Levulan PDT today?

Much depends on your skin type, how strong the sun exposure and time, etc. It the sun had just set it sounds like there was not a large UV exposure post treatment. Your physician will guide you on its signifcance.

It doesn't sound like you need to worry.  Indirect exposure after PDT further enhances the reaction.  If the exposure is significant, it could really exacerbate your reaction.  However, it seems like your exposure was minimal.

Daylight PDT or indirect sunlight has been proven as an effective method for PDT treatment. Different parts of the world utilise different methods of delivering light to activate ALA or M- ALA. 1. US - blue light2. Europe, NZ and Australia - 633 nm 37 mj per sq cm red light.3. Europe and Australia- natural sunlight. This method gives you BOTH blue light ( 405-415 nm AND red light at 620-640 nm via NATURAL light.)So does this matter, the answer is no...in fact it could be beneficial. Watch the studies over the next few years. RegardsDr Davin Lim Laser and cosmetic dermatologist, Brisbane, Australia