During recent public appearances, former president Donald Trump displayed mysterious red marks on his hand.

The marks could be spotted on his thumb, index finger and palm as he waved to cameras.

This led to speculations over the cause, and according to some, the issue with Trump’s hand could be a result of a fall, a hand herpes, or even ketchup.

Dr. Joshua Zeichner, an associate professor of dermatology at the Mount Sinai Hospital, was questioned of the potential reasons for the appearance of the red marks. Speaking to Business Insider, he explained, “Rashes on the hands can be caused by a variety of factors, ranging from infections to inflammatory conditions to external exposures.”

Of course, he added that it is not possible to diagnose a skin ailment from a single photo.

Further, Zeichner offered four explanations for Trump’s hand rashes, most of which are certainly less intriguing than the theories floating around the internet.

His hands are too dry?

One of the reasons for Trump’s red marks could be that his hands are too dry. The former president once revealed he’s been a “germophobe,” so this hypothesis of him likely washing his hands too often and making them dry may hold merit. Dry hands may also be a result of cold weather.

Golf-related blisters?

Being a passionate golf player, Trump spends time at the golf court and enjoys the game, so according to Dr. Zeicher, the red marks may result from “friction from activities like golf, weightlifting, or baseball.”

There was lime juice on his hands?

“Even exposure to lime juice in the presence of sunlight can cause a chemical burn to the skin,” or “margarita burn,” according to Zeichner. Trump doesn’t consume alcohol, but a zesty mocktail can leave welts on your skin.

None of the above!

The exact reason for Trump’s red marks on his hand can’t be stated judging from a photo. It can simply be an insect bite, who knows.

During both presidential campaigns, past and present, Trump has bragged about his perfect health state.

As per a medical report signed by Trump’s personal doctor, the former president and business mogul’s general health is “excellent.” Trump shared a report proclaiming his “exceptional” cognitive health on the day of Joe Biden’s 81st birthday.

Regarding the weight Trump lost, the letter by his doctor states it’s a result of “an improved diet and continued daily physical activity.” Further, the doctor claimed Trumps “laboratory analysis” came back more favorable than in prior testing without specific metrics listed.

In 2015, Trump’s doctor said he would be “the healthiest person ever elected to the presidency.” The doctor later admitted that the patient had written the note.

This isn’t the first time Trump’s health to be widely spoken about. During his time at the White House, his physical and mental health came under scrutiny and some even saw him unfit as a head of the country. made headlines for days by talking about how well he did on a test of dementia that he said was an intelligence test. He said the questions were about picking out an elephant and saying “Person. Woman. Man. Camera. TV” over and over.