There are certain risk factors that may increase your chance of developing soy allergy. Heredity may put you at risk for a soy allergy. That means if a family member has had any type of allergy, including food allergies, asthma, or hay fever, you're more likely to develop a soy allergy. Also, if you have another type of allergy, especially another food allergy, you might be more likely to be allergic to soy. Young children may be at a greater risk for soy allergy, as well, since soy allergies generally occur in young children and babies whose immune and digestive systems aren't yet mature.