No idea, but instead of saying it's this or that the logical way to deduce that info would be to remove something from your diet for some amount of time, maybe 2 weeks or so, and see if the symptoms go away or reduce. You removed the grain fed, so if you still have the same symptoms, or worse, or only a little better, remove something else. I'm sorry to say that since you only listed two foods, grain fed and fruit, I'd have to say the next suspect is the fruit.
The only time I get any acne on this diet is stuff not on the diet, and it's not bad, so I surmise for myself none of the raw paleo foods cause acne. But for others it may be different, it could be the fabled detox, or it could be an environmental (non-food) culprit. But I stand by the best way being experimental removal of things one at a time and observation as to whether that helps. Good luck, acne sucks!