acne
"Great product but the side effects are awful! 
I've been using Duac for a week now and literally all of my blackheads have disappeared it's amazing! My spots have also shrank in size a lot and have almost healed and my scars are fading too. The only trouble I have had with Duac is that when I first put it on it dried my skin out a lot and made it extremely flaky and then when I continued to use it, applying it on most of the area of my face I woke up the next morning and both of my cheeks were burning, bright red and really itchy. I stopped using it for a couple of days until the redness had gone and then applied a smaller amount, but still the burning and itchy sensation has returned."