While the public is only now being made aware of Pintauro's diagnosis, he wasn't shy about sharing the news with his friends, including his Who's the Boss? co-stars Judith Light and Tony Danza.
"I told Judith many years ago," Pintauro said. "I tell anyone who asks. To me, it surprises me that it hasn't come out yet ... Tony was great, but I can tell he was a little disappointed for the drugs part more than anything."
Pintauro admitted that he contracted HIV because he wasn't careful and was having unprotected sex. According to the former child star, drugs played a major part as well.
"The drugs were a big problem," Pintauro said, wanting to make it clear that "child celebrity syndrome" had nothing to do with it. "It's the meth. It takes away all your inhibitions."
According to Pintauro, crystal meth is an issue "specifically in the gay community that people aren't talking about."
Pintauro came out publicly as gay in 1997 after the National Enquirer threatened to out him. While his revelation came before many other stars, Pintauro said it was late enough in his life that he had already missed out on some opportunities.
"When I first came out, which was before everybody -- I mean, Ellen [DeGeneres] and I came out the same year. Rosie [O'Donnell] came out four years after I did -- I missed the opportunity to be a beacon of light for gay kids who were going through what I was going through," he told Winfrey.