What are the characteristics of Herpes Simplex Virus (HSV) hepatitis?

From the Guidelines

Herpes simplex virus (HSV) hepatitis is a rare but potentially fatal form of acute liver failure that requires immediate treatment with intravenous acyclovir. The characteristics of HSV hepatitis include nonspecific symptoms such as fever, abdominal pain, and elevated liver enzymes, making diagnosis challenging 1. According to the American Gastroenterological Association institute guidelines, testing for HSV and treatment with acyclovir is recommended in patients presenting with acute liver failure (ALF) due to HSV, despite the very low quality of evidence 1.

Key Characteristics of HSV Hepatitis

• Rare cause of ALF, accounting for approximately 1% of cases 1
• Can be caused by HSV-1 or HSV-2 infection
• More common in immunocompromised individuals, pregnant women (especially in the third trimester), and neonates
• Nonspecific symptoms, including fever, abdominal pain, and elevated liver enzymes
• Diagnosis can be made through liver biopsy, PCR testing of blood for HSV DNA, or serological testing, with HSV DNA being a reliable diagnostic tool 1

Treatment and Management

• Intravenous acyclovir at a dose of 10 mg/kg every 8 hours for at least 7-14 days is the recommended treatment, with dose adjustments necessary for patients with renal impairment 1
• Longer treatment courses may be necessary in severe cases or immunocompromised patients
• Oral suppressive therapy with acyclovir, valacyclovir, or famciclovir may be required after initial treatment to prevent recurrence, especially in immunocompromised individuals
• Early diagnosis and treatment are crucial to improve outcomes, as mortality rates can exceed 80% without prompt antiviral therapy 1

From the Research

Characteristics of Herpes Simplex Virus (HSV) Hepatitis

• HSV hepatitis is a rare condition, accounting for only 1% of all acute liver failures 2
• It has a high mortality rate, with lethality rates of almost 75% 2
• The condition is often clinically unsuspected, with most cases (58%) being first diagnosed at autopsy 3
• Common features at clinical presentation include fever (98%), coagulopathy (84%), and encephalopathy (80%) 3
• Rash is seen in less than half of patients 3
• Typically, anicteric hepatitis is seen in patients with HSV hepatitis 2
• Immunocompromised state is a major risk factor for HSV sepsis, which can lead to HSV hepatitis 2, 4
• Delayed diagnosis without antiviral therapy significantly contributes to the unfavorable outcome 2

Clinical Presentation and Diagnosis

• Patients with HSV hepatitis often present with non-specific symptoms, making diagnosis challenging 3, 5
• The most common examination findings include fever and abdominal tenderness 5
• Only a small percentage of patients (18.2%) have a vesicular rash 5
• All patients have a transaminitis, and a majority (85%) have positive viral cultures 5
• Diagnostic tests may not always be available, and empiric antiviral therapy with acyclovir is often recommended in cases of acute liver failure of unknown origin 2, 3

Treatment and Outcome

• Antiviral therapy with acyclovir is the primary treatment for HSV hepatitis 2, 3, 6, 5
• Early specific therapy can improve outcomes, but sepsis may still prevail 2
• Liver transplantation may be necessary in some cases, with reported survival rates of more than 40% 2
• Lifelong prophylaxis with acyclovir is recommended to prevent recurrence 2, 6