“Cortisone injections are the quickest way to make acne disappear. Acne cysts literally shrink within four to eight hours after injection and continue to improve over the next several days. Pain and swelling of cyst will improve, too. A cyst that was swollen, tender and red within 24 hours will be flattened, less red and therefore less noticeable. Treatment itself does not make the acne look worse before it gets better, unlike many other treatments. This treatment is about prevention as well and is very useful to prevent scarring — acne cysts are those prone to skin scars,” says Gross.