Writing on the Good Charlotte Web site Friday, Madden said he delayed recording vocals for a new album to spend time with Richie at Cedars-Sinai Medical Center.
"So I stepped off the plane after a month out of the country, and basically went straight to the hospital for the week," Madden, 30, said. "But don't worry, all is well and we are home with no problems."
Richie, who once appeared in "The Simple Life," said on the social networking service Twitter last weekend she was prepared for her bout with pneumonia to end, People.com reported.
"Ok cold, it's been 6 days. Lets part ways graciously & keep it moving," Richie, 28, posted on Twitter last Sunday.