Hi J. - My daughter had similar reactions to her first foods too.. I think she was probably 8 months before she had a solid food without a reaction. That was squash. So, she ate only squash for solids for several weeks before we tried rice cereal again. You might just pull back from solids for a while longer.
She is likely more prone to allergies than not. Most allergist will not test a 6 month old though because they are more likely to have false positives.
My daughter went into anaphylaxis at 4 months to a tiny sip of dairy-based formula so, we did have her tested and she was allergic to dairy, eggs and peanuts. I don't think there were any false positives for her.. In the past two years her list has expanded.. she is currently allergic to dairy, eggs, peanuts, peas, cats, dogs, soy, wheat, corn, tomato, sugar, some food additives and preservatives and mold.. The first time she only tested positive to dairy, eggs and peanuts.
If you are nursing still.. try to continue to nurse as long as possible. It does help. Sorry - I am rambling. At any rate maybe call a pediatric allergist and ask what they would recommend and for now stay away from the green beans. Dr. Allen Resnick with Associated Allergist is great. I think he has an office in Arlington Heights and Highland Park.