It's true that sun exposure can have a beneficial effect on the acne. The benefit is related to the blue light emitted by the sun. This blue light was found to reduce the number of acne bacteria and reduce inflammation.
The problem with sun exposure and tanning beds is that they also contain the harmful ultra violet (UV) light. Unfortunately, excessive exposure to UV caused skin aging and increases risk for skin cancer.
Thus, if you like to get the benefit of sun exposure without the the risk of UV exposure, you need to look for high intensity blue light phototherapy. This treatment is available in many Dermatologists’ clinics and can be also done at home with several home use devices. (Look for good devices in the “tips” section or your MDacne daily plan).