Why do I break out when I eat sesame seeds?

I seem to break out whenever I eat any type of nut or seed. Sesame seeds are the worst. However, when I researched this I could not find any link between sesame seeds and acne. This doesn't seem to be a common food sensitivity. Any idea why I may be having this problem and how I should handle it? Should I go to a nutritionist, an allergist or a dermatologist?