If you are concerned about your heath you need to go and see a qualified medical practitioner (A Doctor).
No, but you can get an allergic reaction from breathing in/smelling something you are allergic to.
sometimes
You can have an allergic reaction anyplace where there is something you are allergic to. So simple answer yes.
Something can become swollen from an allergic reaction.
Hives is an allergic reaction. Stepping on something you are allergic to can give you hives.
it means that u are allergic to something like for examplea insect that bit u in the eye or even hay fever
Anti histamines and sometimes steroids are prescribed for allergies
it could have had an allergic reaction to something it ate.
There are many things that can cause a swollen tongue such as an allergic reaction. Body parts swell up and sometimes interfere with your ability to breathe when you have an allergic reaction.
sometimes but not all the time.
NO! An allergy is something that produces a histamine reaction. You can only be allergic to proteins, and sugar is a carbohydrate. You can have trouble managing sugar (e.g. diabetes), or you can be allergic to some pollens that are sometimes in some types of sugar (e.g. honey), but your body absolutely requires sugars to live, so you can't be allergic to it.
Perhaps there is an allergic reaction occurring from something that is on the legs.