Folks, the magic ingredient in the calamine lotion is zinc oxide.
When I was in my teens and twenties, I had terrible cystic acne. Nothing worked, and my heavy alcohol and white bread diet didn't help. I was a sad young lady who hid behind a layer of thick makeup. In my 30s and 40s my acne improved, as did my diet (see any correlation here?) and cutting out alcohol. Also, I began to see a pattern: after I went through a week of eating chocolate and/or desserts and/or loads of starches, I'd get rows of massive, golfball cysts, usually on my chin, jawline, and cheekbone. They would hurt so much, when I smiled or talked or chewed...well, you know how it goes. Throbbing cysts. Bacne. It took me awhile, but finally I learned: don't screw around with the food!
However, during those times--like holidays---when I do overeat on sugary/starchy foods, I've learned that calamine, applied to the cleansed (erupted) area at night will shrink that ball. The following morning I again cleanse the area, reapply the calamine--if you rub it in the pink fades, leaving a pale whitish area and then cover with a light water-based nude tone. After about 2 days the cysts have shrunk to the size of a grape seed. The only negative is that the top layer of skin is a bit dry, but that's nothing I can't deal with.
There is a tremendous amount of scientific and medical literature out there which indicates most acne (bacterial infection) is generated from gut imbalance. I will encourage anyone who wants to improve their complexion to read about gut health and skin. Through diet changes, a short-term round of antifungal medication (for Candida), followed by a complete reestablishment of the intestines with probiotics and homebrewed kefir, and jump-starting the "elimination system", there will be a massive improvement.
Please, educate yourself on the gut-skin-brain triangle, well-researched since the 1920s. Sadly, it has been ignored.