In some cases, people who are
allergic to wheat, beans (legumes), milk or other foods can have an
allergic reaction to soy. You can confirm this by blood test to see for raised IgE levels and skin testing for soy products.
I would suggest you obtain a referral to an allergist or an ENT who does allergy testing. Some allergies can be life-threatening as they can precipitate anaphylactic shock in which the swelling can be so severe that it impairs the ability to breathe.