I spent my pre-teens and teens going to a dermatologist. He kept prescribing one topical medicine after the other, and I swore every time I used it, my skin would breakout 10 times worse than before. A lot of money was wasted, and eventually I gave up on the dermatologist.
A few years later, I was diagnosed with something called a Salicylate Sensitivity. Salicylates are preservatives found in nearly everything that comes from the earth (fruits, veggies, beans, nuts, etc.) It protects these things from fungus and bacterial infections. Salicylates are also is added to many household products (shampoos, sunscreens, makeup, toothpaste) to keep them fresh. Topical acne creams often use salicylates because, for someone without this sensitivity, it helps to clear up their skin really well. However, if you do have a salicylate sensitivity, it can harm your skin and cause terrible skin reactions.
I just wanted to let other people know about my experience, in case they are having the same trouble I did with the standard topical acne treatments out there. If you think you might have a salicylate sensitivity, there are sal-free acne products available, that you can google and see if they work for you.
There is no test for a salicylate sensitivity. In my case, certain shampoos and lotions caused me to break out in hives or with acne. Also, a lot of fruits and veggies made me feel crummy, as did certain ice creams and other foods with added preservatives. Once a doctor realized that salicylates were the common denominator in all of my seemingly unrelated problems, and he told me what to avoid, my health did a complete 180. I had more energy, I stopped feeling nauseous and depressed, my skin cleared up. Everything improved!