Introduction
- A self-limiting disease that is usually caused by viruses. As it progresses, it causes fibrosis (scarring), cirrhosis and cancer of the liver
Signs and Symptoms
- The majority of acute viral hepatitis infections are asymptomatic or they can cause an anicteric illness that may not be diagnosed as hepatitis
- Hepatitis A generally causes minor illness in childhood with >80% of infections being asymptomatic
- Adults are more likely to produce clinical symptoms
- Hepatitis B, C and D may also be asymptomatic
- Symptomatic hepatitis B will depend on the mode and time of transmission
- Vertical transmission from mother to child is almost always asymptomatic
- Other routes of transmission are more likely to produce symptomatic disease (30% of cases transmitted by IV drug use are icteric)
- Nonspecific systemic symptoms (eg myalgia, nausea, vomiting, fatigue, malaise with discomfort in the right upper quadrant of the abdomen)
- Altered sense of smell or taste, coryza, photophobia, headache, cough, diarrhea, dark urine and serum sickness-like syndrome
- Hepatomegaly, splenomegaly and lymphadenopathy may be seen on physical exam
- Jaundice, usually noted after onset of fever or upon lysis of fever
- Development of symptoms of hepatic encephalopathy (eg confusion, drowsiness within 8 weeks of symptoms or within 2 weeks of onset of jaundice)
- Hypoglycemia, prolonged prothrombin time (PT)
Pathogenesis
Routes of Transmission of Hepatitis
Hepatitis A: Oral-fecal
Hepatitis B: Perinatal, percutaneous, sexual, close person-to-person contact ie by open cuts and sores
Hepatitis C: Blood transfusions, organ transplants, percutaneous (especially IV drug use), sexual, perinatal
Hepatitis D: Sexual, percutaneous especially IV drug use
- Found only in patients with hepatitis B since it requires the hepatitis B outer coat
Hepatitis E: Oral-fecal, blood transfusion in endemic areas
Incubation Period
Hepatitis A: 15-50 days
Hepatitis B: 40-180 days
Hepatitis C: 20-120 days
Hepatitis D: 30-180 days
Hepatitis E: 21-60 days
Other Characteristics of Hepatitis Viruses
- Hepatitis B virus contains a DNA nucleic acid while A, C, and E viruses have an RNA nucleic acid
- Hepatitis D has an incomplete RNA and needs the B virus to replicate
- Hepatitis A and E viruses cause epidemics
- Hepatitis B, C, and D viruses may predispose to chronic disease and hepatic malignancy