FDA warns of 'rare but severe itching' after using popular allergy medications

(NEXSTAR) – Hundreds of people who stopped using allergy medications like Zyrtec and Xyzal noticed an uncomfortable new side effect, the U.S. Food and Drug Administration said in a warning issued this month. In "rare but severe" cases, and for unknown reasons, some who quit using the drugs became very itchy and had to seek medical help.

"Reported cases were rare but sometimes serious, with patients experiencing widespread, severe itching that required medical intervention," the FDA said.