The 30-year-old singer stepped out at the 'X Factor' premiere party in Los Angeles on September 11 and red patches on her left ankle and right heel were clearly visible, reported Daily Mail.
"Britney has had the skin condition for a long time, but it only flares up when she's under extreme pressure. Now she can't seem to stop scratching and picking at the sores. She has a psoriasis skin cream, but she says it burns, so she stopped using it," a source said.
However, Spears is not the only star said to suffer from the autoimmune disease. Socialite Kim Kardashian also had said last year on 'Keeping Up With The Kardashians' that she had developed the skin disease, exposing an angry red rash that spread from her legs to her stomach and all over her body.