Purpose: We present two children who developed a deficiency of factor XIII with valproate (VPA) treatment. This coagulation disorder has not been described in association with VPA treatment in children, and only very recently in one adult patient.
Results: Both patients showed recurrent epistaxis as major clinical sign of a combination of decreased coagulation parameters (factor XIII deficiency with thrombocytopenia and decreased von Willebrand factor, respectively). A few days after reduction or withdrawal of VPA treatment, clinical symptoms disappeared, and laboratory findings were within normal range.
Conclusions: VPA is known to influence the synthetic function of the liver and the number and function of megakaryocytes. Therefore an alteration of the factor XIII level by VPA is conceivable. Our case reports suggest that bleeding symptoms during VPA treatment may be caused or aggravated by a decreased factor XIII activity. A determination of factor XIII activity should be considered before surgical procedures during VPA treatment to minimize the risk of (severe) postsurgical bleeding complications.