Hepatitis A virus infection
The typical incubation time is 28 days (range: 15-50 days). In young children (<5 years), the vast majority of infections are asymptomatic, whereas in older children and adults, icteric infections are almost as common as anicteric forms. Symptomatic patients infected with hepatitis A experience a constellation of symptoms, including fever, fatigue, anorexia, abdominal pain, nausea, vomiting, pruritus (due to hyperbilirubinemia), and/or jaundice (typically preceded by onset of dark-colored urine). Physical examination often reveals hepatosplenomegaly. Laboratory findings typically include elevated transaminases and bilirubin. Rare extrahepatic manifestations of hepatitis A include arthralgias, hemolytic or aplastic anemia, acalculous cholecystitis, myocarditis, toxic epidermal necrolysis, glomerulonephritis, and cutaneous vasculitis.
Hepatitis A is usually a self-limited disease that does not lead to chronic infection or chronic liver disease. However, 10%-15% of patients can experience transient relapses of symptoms within 6 months following the initial hepatitis A episode. Fulminant hepatitis A, with a case fatality rate of approximately 0.5%, can lead to acute liver failure and may require emergent liver transplantation.
Pediatric Patient Considerations:
The majority of pediatric hepatitis A infections are asymptomatic or clinically unrecognized. Hepatitis A causes symptomatic illness in only 30% of adolescents and children compared with 70% of adults.
Immunocompromised Patient Considerations:
Patients with underlying chronic liver disease, including chronic hepatitis B or C, are at increased risk of morbidity and mortality due to acute hepatitis A.
Among pregnant individuals, there is no evidence to suggest that acute hepatitis A is associated with an increased case fatality rate.
B15.9 – Hepatitis A without hepatic coma
40468003 – Viral hepatitis, type A
- Drug-induced hepatotoxicity (eg, acetaminophen) – Consider relevant exposure history.
- Viral hepatitides (hepatitis B, C, D, and E viruses, cytomegalovirus, Epstein-Barr virus [see, eg, mononucleosis], herpes simplex virus, coxsackie virus, yellow fever virus) – Consider relevant clinical findings and epidemiological history.
- Syphilitic hepatitis (uncommon presentation of secondary syphilis)
- Acute toxoplasmosis
- Autoimmune hepatitis
- Fatty liver of pregnancy – Consider clinical context.
- Toxin exposure (eg, acetaminophen, hydrocarbons, halothane) – Review exposure history.
- Bacterial infections (relapsing fever [tick-borne], leptospirosis, ehrlichiosis, Rocky Mountain spotted fever) – Consider relevant exposure history.
- Acute circulatory collapse and hypoperfusion (ie, "shock liver") due to cardiovascular and/or acute bacterial sepsis – Should be considered in appropriate clinical context.