Swelling under left eye, any ideas?

[TheLaineyWayIsEssex]

Woke up this morning and my left under eye/ eye bag was really swollen and puffy. It is not sore, but slightly bruised feeling and is slightly darker in colour than usual. I have taken anti histamine but no change.
I have checked and don't have a style. It is not conjunctivitis. The only plus is that I look like I've had restalyne injected into it, so half of me looks younger.
Your wisdom is sought and welcomed as google is not helping.

Could be urticaria (hives) if you have a skin rash anywhere as well.

Nothing elsewhere, just under the eye. I even thought at be point that DP might have elbowed me in his sleep, but no real bruise, just swelling.
Bizarre

Don't want to scare you but dd had the beginnings of peri-orbital cellulitis last year,and it started in a similar way.Our GP thought it was an allergic reaction to something but after piriton made no difference we went to A+E. She was fine after anti-biotics but it can be very serious so get it checked out asap.

Oh will get down to walk in tomorrow. Thanks I'll go google

the images on google look pretty extreme.My dds eye looked like a lesser version,the docs thought she was at the beginnings of it,and within an hour of the first dose of anti-biotics you could see the swelling had receded slightly.Much better by the next day,it took a couple of days to go completely.