Allergists know that you can get allergies from your skin care. And the more eczema or skin problems you treat with allergens in skin care the more likely you are to develop more allergies. And now they know you can develop food allergies from things you put on your skin.
The AAAAI.org, the most prestigious group of allergists now recommend “bland skin care”. Your skin care needs to be free of known allergens like nut oils (shea butter is a nut oil) or soy (just about anything with “soy” or “soj” means soy.) For Food the FDA lists the Top 8 allergens. Corn used to be on it and should still be.
So if you have a rash, do not put any creams or washes that contain common food allergens or corn.