What causes, including medications, can induce acne overnight, every night?

Dr Theng has answered you wonderfully. And yes hormonal acne can be a common cause of back acne. You may need to advise us further on whether you might be on any meds that throw your hormones out of whack. You can treat it like face acne, and I have used a combination of acne topicals and chemical peels/laser treatments for my patients with back acne conditions.

Hi V – it’s important to use a sunblock, not to prevent oily skin, but to prevent skin aging and skin damage – in the form of wrinkles, pigmentation, increased risk of skin cancer. If you are prone to oily skin, you can go to Watsons/Guardian etc in Singapore to buy a sunblock with SPF 50 that’s suitable for acne-prone skin. These are usually non-comedogenic: ie oil-free, alcohol-free and with a water base.