hi..thanks for the query.
Several anti acne
medications ,both oral and topical make the skin photosensitive when being used or even much later.I am not sure which are the ones you have used,but would advise you the following for sure:
1.Check for the UV coverage spectrum of your current sunscreen;it should be broad spectrum with both UVA& B coverage.Use it very liberally 20 mins before sun exposure ,also carry it with you and reapply.Most sunscreens loose efficacy after 3-4 hours.Even if you face computer screens ,you must reapply even 4 hourly.This is the basic of any treatment.
2. You may start a few sessions of Glycolic Peels (20% -50%) every 15-30 days.This helps in lightening tone of skin and exfoliates much better than any other method.
3.Do not use ant OTC moisturizers/ creams/ fairness agents as many of these have components to make you photosensitive.Use gel based medicated moisturizers.
Hope you find this relevant, take care!