When 21-year-old Rhiannon Douglas saw a red, splotchy rash on her leg last May, she shrugged it off as a shaving rash. But instead of going away after a few days, the rash grew worse enough to cause Douglas to go to her doctor out of concern. According to Cosmopolitan U.K. , she was initially told that she had Henoch-Schönlein purpura (also known as HSP), a disease in which blood vessels in the body become inflamed and swollen, causing bleeding into the skin and, therefore, rashes. However, when her symptoms didn't ease after taking painkillers, Douglas grew increasingly worried and consulted her doctors again, eventually going to the hospital for the discomfort she was experiencing. "The rash on my legs was really painful at first but then after a while my legs also started to swell and I suffered bad pain in my joints," she told Cosmo U.K. "I was struggling to get up and down the stairs and I became breathless really easily." At the hospital, doctors found an 8.5-centimeter tumor in her chest and diagnosed Douglas with a rare form of Hodgkin lymphoma , a form of cancer that spreads through the vessels and glands in the body. And if she hadn't found the rash, it may have taken much longer to diagnose the disease and treatment would not be possible. Luckily, Douglas told Cosmo U.K. that the tumor in her chest had reduced in size with the last scan she did, and is now 7.5 centimeters long. However, she wants to raise awareness about rare symptoms of cancer, such as the one she experienced, so that others might be able to find their diagnosis sooner. "I would urge anyone to get themselves checked out if they are unsure of anything as you just never know what it might be," she said. "But I also think it's also really important not to put a death sentence on the word cancer, I have a really positive outlook and I'm hoping to be in remission by the summer."