Why didn't you cut it after 3 days then? You let it develop into cystic acne? You must really love cauliflower.
I doubt anyoe is going to be able to tell you "why". It is unusual and the first I've heard of cauliflower or onion causing acne. If you really think they cause acne, cut them and move on without them.
I think everyone has different food intolerances. What might break someone out with one food could be perfectly fine to eat for another. I know if I eat a lot of chocolate and sweets I will later break out however, if I eat onions they don't seem to have any effect on my acne. Everyone skin is unique
Your gut may not be in terrific shape. If that's the case, it would be very hard for you to digest cruciferous vegetables without some intestinal distress. Repeated intestinal distress from ANY food (NOT just gluten) will lead to inflammation. Sugar and (cow's) milk both equally lead to to enormous amounts of inflammation in pretty much everyone. Inflammation on its own will just lead to skin sensitivity and redness, but when you couple that with unruly sebum levels, you get the magic recipe for acne.
Do some research on leaky gut and see if you identify with any of the the common symptoms. It's my opinion that just about ALL acne sufferers can benefit from some TLC to their gut lining. If your gut was in a healthy place, your skin would probably respond quite well to cruciferous vegetables. If your gut is leaky, you'll have all sorts of bizarre allergic reactions to all kinds of foods. When your gut is leaky, food particles can escape your intestinal walls and enter your blood stream, at which point your immune system attacks them as they would any foreign object. It's why it's called an 'autoimmune' response.
Digestive enzymes and/or supplemented HCL would likely also be of great benefit to you.
