Swelling of eyelid due to allergy or conjunctivitis?

Dear Ask The Doctor: Hi there I went to work two weeks ago with a headache so I took 2 paracetemol. There was a customer that sneezed all over his hand, obviously I drowned my hands in disinfectant gel after taking his change. But when I got home maybe 7 hours later I was watching TV and my eye had swollen to the size that It was turning purple. I cleaned it out with warm water and salt and put an ice pack on it. It went away within 2 days but I went to my doctors anyway and he said it must have been an allergic reaction to something that was on your hands and then touched my eye. So naturally I thought it was the disinfectant gel. So I was back at my work yesterday with yet another headache that I woke up with. And 20 minutes into my shift my left eye swelled up again. But this time when my eyes closed they felt as though they were bruised and it hurt. Even the swelling was travelling up the side of my head to the temple. I am beginning to get worried if the headaches are linked to the eye swelling and if there are any underlying conditions. Would you be able to give me any advice on diagnosis or advice what could be causing it?

Dear Nikki: While it is entirely possible that you have acquired infectious pink eye, it is also possible that the swelling is due to an allergy. Conjunctivitis (the medical name for pink eye) can either be infectious (caused by either a bacteria or a virus) or it can be caused by something else, such as an allergy. In most cases, it is caused by a virus. This, unfortunately, means that antibiotics are useless, and you just need to wait for the redness and itching to resolve by themselves, which usually takes about the same amount of time as it takes to get over the common cold. Generally, they are treated with warm compresses to the eye and good hand hygiene. However, there are some cases of conjunctivitis that are caused by bacteria, and these should be treated with an antibiotic, usually just a topical antibiotic eye drop or eye ointment. Typically the conjunctivitis that is caused by a bacteria infection results in larger amounts of thick eye drainage and increased redness and pain.