Transient lupus anticoagulant associated with prothrombin deficiency: unusual cause of bleeding in a 5-year-old girl.

We present the association of a lupus anticoagulant with hypoprothrombinemia in a 5-year-old girl, who presented with ecchymoses and a hematoma. This coagulopathy should be included in the differential of bleeding in the previously healthy children.Coagulation and immunology laboratory evaluation was performed at the time of presentation with bleeding and 2 months later, after complete clinical recovery.A 5-year-old girl presented with ecchymoses and a hematoma after after an upper respiratory illness. Laboratory evaluation showed prolongation of both the prothrombin time (PT) and activated partial thromboplastin time (aPTT) due to the presence of a strong lupus anticoagulant associated with a decreased level of prothrombin (15 U/dl). Hypocomplementemia was also detected. Bruising resolved spontaneously, and the PT and aPTT gradually normalized. Reevaluation 2 months later showed that the lupus anticoagulant had disappeared and the prothrombin deficiency was markedly improved.This case demonstrates that transient lupus anticoagulants must be included in the differential for bleeding in young children. Also, in children with lupus anticoagulants, neither the association of hypoprothrombinemia nor the presence of evidence of activation of the immune system appears to predict whether a patient will have or develop systemic lupus erythematosus.