In 3 cases the cause of FHF was unknown;in 2 cases, it was induced by paracetamol overdose;and in 1, by acute hepatitis B virus.

• 3例中导致FHF的原因不明，2例是由对乙酰氨基酚过量导致的，1例是由急性B型肝炎病毒导致的。