By Dana Kozlov

(CBS) — Out of the blue, a northwest suburban man is gasping for air, having a first-ever allergic reaction to something he ate.

As CBS 2’s Dana Kozlov reports, he gets a life-saving shot after running into a drug store.

Fifty-seven-year-old Mark Davey stands a few feet from his life-saving and life-altering experience inside a CVS pharmacy — a trip he made last month after an unexpected allergic reaction.

“As I’m eating lunch, my tongue starts to swell up, and I think something really bad is about to happen,” he says.

Davey never had a food allergy before but knew he needed help. So, he drove himself to the CVS in Bartlett for Benadryl. He says pharmacist Bhavini Patel took action after calling paramedics.

“Shortly after, she gave me an epinephrine shot,” he explains.

Bartlett paramedic Victor Arlis says the pharmacist’s action probably saved the man’s life.

Davey “could have gone down the drain really quick,” Arlis says.

A spokesperson for CVS would not allow CBS 2 to talk with the pharmacist on camera. She tells Kozlov by phone she knew exactly what was going on and was glad she could help.

Davey now carries an EpiPen everywhere. And paramedic Arlis says the incident is a reminder that food allergies can materialize any time.

Paramedics say if you suspect you’re having an allergic reaction, it’s best to call 9-1-1 right away.