Symptomatic venous thromboembolism in Hong Kong Chinese children.

OBJECTIVE To determine the incidence of venous thromboembolic disease in children of Chinese origin, and associated predisposing factors. DESIGN. Retrospective case series. SETTING A general, public hospital serving a population of approximately 181,000 children in Hong Kong. PATIENTS AND METHODS Hong Kong Chinese children under the age of 15 years who were diagnosed with a symptomatic venous thromboembolic event between 1995 and 2000 were included. Data on clinical features, predisposing factors, treatment, and outcome were obtained from review of hospital medical records. RESULTS Eight children (five girls and three boys) of mean age 11.5 years (range, 0-14.7 years) were included in the study. They presented with deep vein thrombosis (n=4, with pulmonary embolism in one), superior vena cava thrombosis (n=1), and cerebral venous sinus thrombosis (n=3). Predisposing factors included hereditary protein C deficiency (n=3), protein S deficiency (n=2), anticardiolipin antibodies (n=1), malignancy (n=3), recent neurosurgery (n=2), infection (n=1), with multiple predisposing factors seen in three patients. Anticoagulant therapy was prescribed in five patients, and long-term warfarin therapy was required in two cases. Venous thromboembolic disease resolved in all children, but one patient had a recurrence after cessation of warfarin therapy, and one patient had post-thrombotic syndrome. CONCLUSION The rate of venous thromboembolic disease in Hong Kong Chinese children was comparable to that seen in Caucasian children, with an annual incidence of 0.74 per 100,000 children. Predisposing factors, including hereditary prothrombotic conditions, were common.