What is the cause of acute liver failure in a pregnant woman with a maculopapular rash and arthralgia?

Acute Liver Failure with Maculopapular Rash and Arthralgia in Pregnancy

The most likely cause is acute viral hepatitis, particularly herpes simplex virus (HSV), which should be treated immediately with acyclovir given the significantly increased maternal and fetal mortality risk in pregnancy. 1, 2

Diagnostic Approach

Primary Consideration: Viral Hepatitis (Especially HSV)

The combination of acute liver failure with maculopapular rash and arthralgia in a pregnant woman strongly suggests viral hepatitis, with HSV being particularly concerning:

• Pregnancy (especially third trimester) significantly increases the risk of ALF due to herpes virus, which presents with systemic symptoms including rash 1
• HSV hepatitis carries significantly increased maternal and fetal mortality rates in pregnancy 2
• Immediate empiric acyclovir treatment is indicated when HSV is suspected, even before confirmatory testing 1

Secondary Considerations

While pregnancy-specific liver diseases (AFLP and HELLP syndrome) are common causes of ALF in pregnancy, they typically do not present with the combination of rash and arthralgia:

• AFLP and HELLP syndrome account for approximately half of pregnancy-associated ALF cases 3
• However, these conditions typically present with the triad of jaundice, coagulopathy, and low platelets, often with features of pre-eclampsia (hypertension, proteinuria) 1
• Rash and arthralgia are not characteristic features of AFLP or HELLP syndrome 1

Other Viral Etiologies to Consider

• Hepatitis E virus (HEV) causes high mortality in pregnant women, particularly from endemic countries like India 2
• Acute viral hepatitis A, B, C, D should be evaluated, though the course is generally unaffected by pregnancy (except HEV) 2

Management Algorithm

Step 1: Immediate Empiric Treatment

• Start acyclovir immediately if HSV hepatitis is suspected, given the high mortality risk 1
• Do not delay treatment while awaiting confirmatory testing 1

Step 2: Diagnostic Workup

• Obtain HSV PCR, viral hepatitis serologies (including HEV if from endemic area) 2
• Assess for pregnancy-specific conditions: check for hemolysis, platelet count, coagulation profile, blood pressure, proteinuria 1
• Apply Swansea criteria if AFLP is suspected (≥6 criteria correlate with diagnosis) 4

Step 3: Determine Severity and Need for Intensive Care

• Admit to ICU if encephalopathy develops, serum lactate is elevated, MELD score >30, or Swansea criteria >7 4
• Monitor for hypoglycemia, which is characteristic of AFLP 4
• Correct coagulopathy and metabolic derangements 4

Step 4: Obstetric Management

• If pregnancy-specific liver disease (AFLP/HELLP) is confirmed, expedited delivery is critical once coagulopathy is corrected 1, 4
• Early recognition and prompt delivery are critical for achieving good outcomes in pregnancy-specific liver diseases 1
• Recovery is typically rapid after delivery with supportive care 1

Step 5: Transplant Evaluation

• Early referral to a transplant center is indicated for severe hepatic impairment 4
• Postpartum transplantation may be necessary in severe cases 1
• Overall, 16% of pregnant women with ALF require liver transplantation and 11% die 3

Critical Pitfalls to Avoid

• Do not delay acyclovir treatment while awaiting HSV confirmation - the mortality risk is too high 1, 2
• Do not assume all ALF in pregnancy is pregnancy-related - only approximately 50% of ALF cases during pregnancy are actually AFLP or HELLP syndrome 3
• Do not overlook acetaminophen toxicity, which accounts for 60% of non-pregnancy-related ALF cases in pregnant women 3
• Do not miss hepatitis E in women from endemic countries - it carries particularly high mortality in pregnancy 2