Systemic lupus erythematosus presenting with pulmonary thromboembolism in a 15-year-old girl

Pulmonary embolism is rare in children aged less than 15 years in whom its estimated annual incidence is 0.2 cases per 100,000, against the approximately 700 cases per 100,000 in patients aged more than 85 years. We describe the case of a 15-year-old girl who had a history of thrombocytopenia with anti-platelet and anti-nuclear antibodies. Misdiagnosed chest pain and dyspnea were treated for 6 weeks as community-acquired pneumonia, but proved to be the onset of pulmonary thromboembolism. Although this life-threatening event is rare in paediatrics, the presence of lupus anticoagulant combined with previously asymptomatic thrombocytopenia allowed a diagnosis of systemic lupus erythematosus (SLE). The combination of a history of thrombocytopenia and the presence of antinuclear antibodies, even in the absence of any other diagnostic criteria, should always suggest considering SLE as a differential diagnosis, particularly when the course of a clinical manifestation is atypical.