When nine-year-old Chow Shing-yan was admitted to hospital with fever, a rash and stiff joints, doctors initially thought it was meningitis. The little girl's limbs were limp and she suffered seizures, quickly falling into a coma. But an emergency brain scan diagnosed arthritis - or paediatric rheumatism.
It's not the type of joint pain that elderly people often suffer, but the kind that leaves young children screaming in agony. The disease is often misdiagnosed, leading to twisted, deformed limbs, renal failure, blindness and even death.
Lee Tsz-leung, an associate consultant in Queen Mary Hospital's paediatrics and adolescent medicine department, says most people think rheumatism affects only the elderly, but he estimates about 3,000 children in Hong Kong suffer from the disease. Symptoms include joint pain or swelling which restricts movement, a rash on the face and palms, and a fever that can last up to a month.
'The cause is relatively unknown, but we think there are multiple factors, including genetic and environmental influences such as viruses, overexposure to the sun and passive smoking. Hormones may play a part, as can stress, which often causes the disease to flare up,' he says. The disease is usually first evident in children from newborns up until puberty. 'At this stage in life it is often difficult to deal with,' Lee says, 'especially for adolescent girls because the steroids [used to suppress the inflammation] make them gain a lot of weight.'
In severe cases, cytotoxic drugs (often used in the treatment of cancer) are also needed.
Lee says: 'When they are students they find the situation difficult because they cannot do what their friends can do - the chronic pain affects their walking ability and the drugs affect fertility.