When the propionate ester is cleaved in your body it becomes propionic acid. It won't mess you up like a bee sting allergy. It's not the formic acid in the sting that causes the anaphylaxis but it does cause some swelling and pain around the sting site, just like the propionic acid can cause swelling and irritation around the injection site.
If you are very prone to allergies you will be more likely to get a reaction to test prop, but your immune system gets used to it pretty quick. Loratadine should help.