For someone with a mild (Level 1) tomato allergy, are there any kinds
of tomatoes that are safe to eat (that don't cause allergic reaction)?
 If not, is there another vegetable that is a good "substitute" for
tomatoes in recipes that call for tomato, such as pasta sauce?

Some of the suggestions here might be of interest to you:

http://boards.straightdope.com/sdmb/showthread.php?t=307533

If you have a true allergy (i.e. you get hives, congestion, etc) to
tomatoes and not an intolerance then there aren't any tomato products
that you should have.

Pesto is a great substitute to use with pasta. You can buy pesto all
ready prepared in most supermarkets.

Good Luck!

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