Valproate-related peripheral oedema: a manageable but probably neglected condition.

Valproate-related peripheral oedema is usually regarded as a problem occurring after long-term administration of valproate. The scarcity of reports is partially responsible for the lack of a full understanding of this condition. This report describes two patients acquiring peripheral oedema after short-term use of add-on therapy with valproate. The oedema could appear and reappear quickly. Discontinuing valproate resulted in rapid improvement of this condition, and the cause-effect relationship was supported by double challenge. We also put forward a preliminary hypothesis to explain this treatable situation.