After being told by three doctors (two dermatologists and one general practice) that my crazy skin reaction was a lime burn, I decided to believe them rather than all the people who were telling me that it's not possible for lime to do that.
Here's what happens. If someone has citric juices on them (be it from limes, lemons, oranges, etc.) and then is exposes to the sun, phytophotodermatitis occurs-- or simply, you get burned. This can also happen with other plants like certain meadow grasses, parsley, celery, and fig leaves.
It's often misdiagnosed because each person has different reactions depending on their skin, the amount or the irritant, and the amount of sun exposure. Some simply have miscoloration, others get what looks like a sun burn, and other (like me) burn badly enough to blister and swell.
So how not to get a lime burn? Wash yourself thoroughly with soap and water after cooking with limes or making lemonade or limeade. If you've got it? Hydrocortisone cream and no more sun is the key to it healing.
For more information, check out this report that I found: