5 Surprising Allergies You May Have

Chances are, you've encountered the ingredient called benzalkonium chloride, which can irritate skin. It's often contained in hand sanitizers, so your efforts to fend off the flu may cause your hands to break out in itchiness and redness. Another place you'll find it in: as a preservative in many eye drops, says Neeta Ogden, MD, spokesperson for the American College of Allergy, Asthma and Immunology (ACAAI). Using them could cause similar symptoms in the eye. Ogden adds that because your eye doctor may not realize you're reacting to that specific ingredient, she may give you different eye drops in an effort clear things up. Catch is, they may contain the same preservative, which will only prolong symptoms. Work with your pharmacist to find BC-free drops, Ogden says. As for hand sanitizers, if you're allergic, scan the ingredient list to make sure yours doesn't contain it (some will advertise that they contain no "benzalkonium chloride").

It's well known that costume jewelry can cause an allergic reaction, as these baubles are often made with materials like nickel. Your fitness tracker may also be made with irritating metals. "Skin allergies to new wearable technology is something that may become more common," says Sarena Sawlani, MD, Medical Director of Chicago Allergy & Asthma. In fact, nickel is one of the most common causes of allergic skin rashes, affecting more than 18 million people in North America, according to the American Academy of Dermatology. In 2014, Fitbit recalled one million of these wristbands because of reactions that resulted in redness, rashes or blisters. These rashes happen hours to days after wearing them, so the culprit may not be obvious. An allergist can do a patch test to see what's setting off your skin woes.

Sink your teeth into a big, juicy burger and the unexpected happens: you erupt in hives. Bites from the Lone Star tick can cause this perplexing allergic reaction. "Their bite can sensitize you to a protein that's found in red meat," says Ogden. While it's typically found in the Southeastern and Eastern U.S., these ticks have recently expanded into the Northeast and are causing an increase in the number of cases, according to the Centers for Disease Control and Prevention. "This needs to be on every allergist's radar especially if you've had a rash for a few days and don't know what caused it," she says.

Smart move to slather on the SPF to safeguard skin from the sun's aging and skin-cancer producing rays. But you may notice that your skin has become angry since then. If you're experiencing burning or stinging or seeing a rash, you may be allergic to your favorite sunscreen, says Sawlani. "This is something we see occasionally in our clinic," she says. Most often, people react to chemical-based sunscreens, she notes. But this isn't license to go without SPF. (Ninety percent of melanomas, a deadly form of skin cancer, are caused by UV light.) In those situations, Sawlani suggests switching to a mineral-based sunscreen that contains UV-blockers like zinc oxide or titanium dioxide.

You may expect to be free of sneezing and itchy, watery eyes during the winter, but just because you're not outdoors with pollen doesn't mean you're in the clear. In fact, all the time spent indoors can make you more likely to react to the most common winter allergen: dust mites, which can be found in hoards in the decorative pillows on your bed or sofa. (The fecal matter from dust mites is what sets off allergic reactions, says Sawlani.) Plus, you're probably not throwing them in the wash regularly (if ever), something that can help kill the dust mites. "If you find that you have dust mite allergies, keep bedding to a minimum," she recommends.