The edge of my upper eyelid is a bid swollen. i don't know if it is because of my allergies or a blocked oil gland. my eye is itchy and sometimes hurt?

Hordeolum: A stye(hordeolum)occurs rather suddenly(MayB from rub). It is a blocked oil gland(s) of the eyelid. It can become secondarily infected and can spread to adjacent tissues leading to cellulitis. Most of these styes respond to very warm compresses 3-4 times/day for 10' followed by gentle massage with a washcloth containing a small amount of baby shampoo. After a week, the stye should nearly resolve.