I was diagnosed as being allergic to peanuts and tree nuts as a child but that was 15 years ago. can i try nuts now?

What happened ??: Major allergic rxns to any agent should never be ignored. If you had a rapid onset of abdominal pain, difficulty breathing, etc after childhood exposure it would be a big risk. If you may have had a rash or runny nose or a positive skin test & no sx ever, it might not be a real allergy. An allergist could help you decide your risks by doing some simple tests.

Visit allergist: It is much safer to only reintroduce a food that you were previously told you were allergic to after testing and oral challenge in a supervised setting (e.g. Doctor's office).