Symptoms of Hepatitis A
Hepatitis A typically presents with fever, malaise, anorexia, nausea, abdominal discomfort, dark urine, and jaundice, with symptoms varying significantly by age. 1
Age-Related Symptom Presentation
- In children younger than 6 years, more than 90% of hepatitis A infections are asymptomatic; when symptoms occur, they typically are not accompanied by jaundice 1
- Among older children and adults, infection is typically symptomatic, with jaundice occurring in >70% of patients 1
- Hepatitis A outbreaks in childcare settings are often detected only when adult contacts become jaundiced 1
Clinical Course and Timeline
Average incubation period is 28 days (range: 15-50 days) 1
Initial presentation often includes a 1-7 day prodromal illness with vague symptoms 1:
- Anorexia
- Malaise
- Fever
- Nausea
- Vomiting
Dark urine is often one of the first noticeable symptoms for which medical attention is sought 1
Within days of bilirubinuria onset 1:
- Feces become clay-colored
- Sclera, skin, and mucous membranes become jaundiced
- Hepatomegaly may be noted on physical examination
Duration of illness is variable, but most patients show significant improvement within 3-4 weeks, including resolution of elevated liver enzymes 1
Discoloration of stool typically resolves within 2-3 weeks 1
Infectivity Period
- Peak infectivity occurs during the 2-week period before onset of jaundice or elevation of liver enzymes 1
- Virus is shed in stool and concentration declines after jaundice appears 1
- Children can shed the virus for longer periods than adults, up to 10 weeks after onset of clinical illness 1
- Infants infected as neonates may shed the virus for up to 6 months 1
Complications
Approximately 10-15% of patients experience relapsing disease lasting up to 6 months 1
About 20% of patients with relapsing disease have multiple relapses 1, 2
Cholestatic hepatitis can occur, characterized by prolonged jaundice 1, 3
Fulminant hepatitis A is rare but more common in 1:
- People older than 50 years (case fatality rate reaches 1.8%)
- Patients with chronic liver disease
Overall case-fatality ratio is approximately 0.3-0.6% 1
Special Considerations
- Pregnancy is not a risk factor for more severe hepatitis A virus infections in the United States 1
- Transmission to the fetus is unusual, though rare cases of meconium peritonitis have been reported when mothers develop hepatitis A during the first trimester 1
- Hepatitis A is self-limited and does not progress to chronic infection or chronic liver disease 4, 5
- Extrahepatic manifestations can include evanescent skin rash and transient arthralgias 3
Diagnosis
- Hepatitis A cannot be differentiated from other types of viral hepatitis based on clinical features alone 1
- Serologic testing to detect IgM antibody to hepatitis A virus (IgM anti-HAV) is required to confirm acute infection 1
- In most persons, serum IgM anti-HAV becomes detectable 5-10 days before onset of symptoms 1