Try cutting out dairy. That made a dramatic effect for the better in me. Milk chocolate is probably the worst for me.
Eating a large bar of dark chocolate should differentiate, purely in the interests of science of course.
Also, I would add that most processed dairy (besides just plain old milk) is mixed with many other detrimental ingredients. So there may be a cause/effect relationship overlap with other foods.
Out of curiosity, does chocolate have any other effects on you besides the acne? Like easier bleeding/blood thinning? Or other inflammation besides acne? It has more than one effect on me and I surely can't be the only one observing it.
I consume chocolate in the evening and do sometimes clear walking tracks before breakfast, which often involves scratches. So I would expect to have noticed wounds bleeding for longer than usual.