About two months ago, a friend called me with an emergency (which I knew was an emergency before even answering her call because, like other millennials, we never speak on the phone). The pressing issue? She had broken out in itchy, red welts all over her body overnight and started having a panic attack. And because there's no such thing as TMI amongst friends, she wanted me to come over and take a look. Turns out, she was allergic to an antibiotic she had just taken, which is a common reason for hives.
"Hives are caused by either an over abundance of allergy cells, or overactive allergy cells," says allergist Tania Elliott, MD. "When they get activated, they release histamine. Histamine is responsible for causing itching, redness, and swelling."
For the most part, hives can be treated with an antihistamine like Benadryl (if symptoms don't go away on their own in 24 hours). But as Stanley Fineman, MD, a spokesperson for the American College of Allergy, Asthma, and Immunology, says, allergies aren't the only culprit. And it's not always clear what causes them.