Soya beans can produce allergies in humans. Although children are more susceptible than adults it is indeed a problem since labeling laws world wide do not address this problem seriously.
Many people are allergic to nuts especially peanuts. Soya bean also is a legume and can cause an allergic reaction. If you are allergic to nuts you maybe allergic to Soya and in this situation it is wise to avoid all soy products. More often than not the allergic reaction to soy is mild. However in a few rare cases it may lead to anaphylactic shock which can be dangerous and can lead to deaths from soy allergies.
Sometimes you may not realize that certain foods contain soy. It is very important that you read labels carefully to avoid allergic reactions to soy and soy products especially as soy lecithin is labeled as natural product. Thus you may unsuspectingly consume it in a food or medicine you think does not have soy.