Braxton, 43, was speaking at the 8th Annual Bag Ladies Luncheon, where she picked up a Women in Achievement award.
E! Online reports that as she picked up her award, she said: 'Take a look, this is what lupus looks like.'
Lady Gaga spoke earlier this year about being tested 'borderline positive' for the potentially deadly autoimmune disease.
Braxton, who is a spokeswoman for the American Heart Association, also suffers from pericarditis, which is an inflammation of the heart lining.
This has meant she has suffered from high blood pressure as well as heart palpitations.