Ate something different, now covered in white heads

Oatmeal with brown sugar and margarine.

Now I have white heads all over.

….

Note to self:  Do not eat oatmeal with brown sugar and margarine.

I eat oatmeal normally with no problems at all!  Maybe it was the brand of oatmeal, no clue.  Pre-made $1 stuff in cafeteria, so who knows what the ingredients are.