The disease crept up on her in her teens, causing her joints to turn red and swell up. Then, Ms Yap Bee Geok's fingers also turned purple when she took a cold shower.
Later, she found out this was due to Raynaud's phenomenon, where smaller arteries that supply blood to the skin narrow, resulting in poor blood circulation.
It is a common symptom of scleroderma, where an abnormal immune system causes uncontrolled production of fibrous tissue.
When it first happened, her general practitioner told her it was due to a vitamin deficiency. But her condition did not improve after taking vitamin supplements.
A whole list of symptoms followed. She had eczema-like rashes and joint pain. Later, a bout of severe breathlessness landed her in hospital, and led to her diagnosis.
That was 20 years ago. Ms Yap, now 50 and working as a florist, is better aware of her condition, and takes medication to help her cope with the disease.
But the journey has not been easy.When she was prescribed steriods to prevent inflammation, her face swelled up.
As her condition worsened, pain in her joints and bones became unbearable, and she had to take painkillers up to five times daily.
She also had osteoporosis, a disease in which the bones become brittle from loss of tissue. It made her limp badly, and she had problems squatting or picking things up from the floor.
In 1997, an ulcer appeared on her right index finger, which turned gangrenous after a few months.
It began as a small spot. "It spread and spread, and went into the fingernail," she recalled.
Her doctor pulled out the fingernail, which had turned black, and had to amputate it just above the second joint.
When her then husband moved to China for work from 2001 to 2002, she asked her doctor if she could go along.
"He told me there were three things I must always remember - to cover my head, neck and fingers."
During winter, she sat near the heater mostly. When she went out, she wore three to four layers of clothing to prevent her small arteries from narrowing, which could limit, or even cut off blood supply, to her fingers and toes.
"I looked like a dumpling, but I had no choice," said Ms Yap.
Gradually, her condition stabilised and has even improved.
She is now taking medication to help with acid reflux, and to boost blood flow to her fingers and toes.
"As a florist, thorns can prick my fingers. I take special care to avoid that," she said. "I also make sure to keep my hands, feet and head covered. Otherwise, life goes on."