When life hands you limes, don't squeeze them outdoors.
The otherwise harmless green fruit can lead to chemical burns when its juice reacts with sunlight on your skin, a condition called phytophotodermatitis. Limes are the most common culprit, but it can also be caused by carrots, parsnips, parsley, celery, figs, wild dill, lemons and bergamot oranges.
"Patients come in quite concerned when they have a rash like this," explained Dr. Joshua Zeichner, director of cosmetic and clinical research at Mount Sinai Hospital. "It raises a lot of panic."
Symptoms don't appear until a few days after exposure, making phytophotodermatitis a very sneaky summer-ruiner. They range from mild redness to blisters and second-degree burns, depending on how long you're in the sun and how much of the juice gets on your skin.
However, dermatologists more often see patients once the inflammation has started to fade, leaving behind "a characteristic brown patch on the skin," Zeichner said.
Although the brown patches can be itchy, they will disappear on their own within a few weeks to months. In the meantime, they can be lightened with hydroquinone, said Dr. Carolyn Jacob, director of Chicago Cosmetic Surgery and Dermatology.
Still, if the idea of chemical burns has you swearing off beachside margaritas forever, don't worry: lime burn can be prevented by immediately washing off residue with soap and water or cleansing towelettes.
The condition used to be called "berloque dermatitis" because women developed it from wearing perfume on their necks, Jacob explained. These days, it's more often observed among those returning from vacation.
"This happens more around spring break for us," Jacob said of her practice.
More Health Tips videos
Summer Shape-Up finale: Tips for staying motivated and fit all season long
Summer Shape-Up finale: See how much weight 3 viewers lost in 4 weeks
In wake of Manchester bombing, how to talk to your kids about terror
Drop 10 TODAY: Joy Bauer shares her slimming smoothie recipe
And whatever your vacation plans, Jacob advises wearing plenty of sunscreen.