A dermatologist offered some possible explanations after Former President Donald Trump was seen with mysterious red marks on his hand, sparking speculation about his health. What Happened: Trump was photographed with red marks on his hand as he left his New York residence to attend the second defamation trial of E. Jean Carroll, reported Business Insider. People on social media quickly began speculating about the cause of the marks, suggesting everything from “hand herpes” to a recent fall. Dr. Joshua Zeichner, an associate professor of dermatology at Mount Sinai Hospital in New York City, sha…