Donald Trump's case of the sniffles at Monday's debate prompted a bizarre charge from onetime Democratic presidential candidate Howard Dean, who mused on Twitter that the GOP candidate may be a "coke user."

While much of the pre-debate hype focused on whether Democratic nominee Hillary Clinton, who Dean supports, would have a coughing fit, it turned out Trump was the one with respiratory issues. The developer-turned-politician repeatedly sniffed into the microphone as he addressed the auditorium at New York's Hofstra University and a TV audience that could approach 100 million.

"Notice Trump sniffing all the time," tweeted Dean. "Coke user?"

The remark quickly gained more than 7,000 retweets and more 7,772 likes. But it also prompted a wave of criticism directed at the former Vermont governor.

“Said the Vermont acid freak,” responded Twitter user Mikey Adams.

“It’s a stupid comment from someone who should be taking the high ground,” tweeted Ryan Miller.

Trump famously claims to have never touched alcohol or smoked so much as a cigarette, so Dean's suggestion the 70-year-old turned to hard drugs on the biggest night of his nascent political career came out of left field.

Trump told Fox News Channel's "Fox & Friends" Tuesday that there were "no sniffles" and that he didn't have a cold.

"There no sniffles," Trump said in a phone interview. "Maybe it was the mic. There were no allergies, no cold."

Clinton, who nearly collapsed earlier this month during a 9/11 memorial ceremony amid a bout with pneumonia and has had several coughing fits while on the campaign trail, appeared healthy and sharp during the 90-minute debate.