Lee Jin-wook shocked viewers with a bizarre health secret when he admitted to having an alcohol allergy so severe that even swabs used in hospitals and medicinal foot patches cause reactions.

On 2 August, the YouTube program Yoo Yeon-seok's Weekend Yeon-seok Drama had Lee join co-star Jung Chae-yeon and spend time with host Yoo Yeon-seok. The two are on screen together currently in the drama Esquire.

"I've never had a sip of alcohol in my life. It's not that I gave up alcohol — I simply cannot drink," Lee said, raising eyebrows from his co-stars.

He reminisced about an amusing but unexpected experience: "I once ate chocolate which contained whiskey and I ended up being drunk.

My face was flushed and people laughed at me." Jung replied, "That's such an unexpected charm about you."

Lee explained that it's not an issue of poor drinking tolerance, but a real allergy. "I was very exhausted once and wore one of those foot patches. My heart began racing suddenly, and my face turned red — it was due to alcohol from the patch being absorbed via my feet," he said.

READ MORE: Lee Jin Wook In His 'Lover Boy' Era? Actor Offered to Headline Romance Drama 'My Dear Harry'

The issue is also one of skincare. When Yoo asked, "What about skincare products?" Lee said, "When I use the strong ones formulated for men, my skin becomes red. When they massage me with alcohol swabs at the hospital, the red mark remains in that precise shape. But nobody believes me."

Lee's allergy news soon spread like wildfire throughout the online forum Pann.nate, eliciting a chorus of shocked and sympathetic comments:

"Huh??? Ah~ Really???? This is amazing. ㅎㄷㄷㄷㄷ"

"t looks like it's advertising whiskey lol."

"Wow... even whiskey chocolate can make him drunk? That's a real twist!"

"It's not something to joke around about — alcohol allergies can be really serious."

"There's even alcohol in foot patches? No wonder his reaction was so bad."

"Allergies are scary... It seems like it's great to know and protect your body well."

"You're still sexy, Lee Jin-wook! You don't need to drink to be charming."

Though alcohol intolerance is fairly frequent, actual alcohol allergies are uncommon and can lead to severe symptoms, such as skin rashes, quickened heartbeat, and flushing from minimal exposure.

Lee's candor has earned applause for bringing to light a condition that few people know about.

READ MORE: Lee Jin Wook Talks About His Naked Scene in 'Sweet Home' Season 2, Incident With G-Dragon