Acute hepatitis in children

Overview

Acute hepatitis means inflammation and necrosis of the liver of recent onset. In Pakistani children the commonest cause is hepatitis A, spread by contaminated food and water, and most children recover fully. The key exam skills are choosing and reading the serology, recognising the child who is sliding into acute liver failure, and knowing the prevention (hygiene, vaccines, HBIG).

Aetiology

Hepatitis viruses at a glance

Pathophysiology (brief)

• Hepatotropic viruses infect hepatocytes; injury is largely due to the immune response against infected cells.
• Hepatocyte damage releases ALT and AST; swelling and bile duct injury cause cholestasis (raised conjugated bilirubin, ALP).
• Severe necrosis lowers synthesis of clotting factors (prolonged PT), albumin and glucose, and failure to clear ammonia leads to encephalopathy.

Clinical features

Phases

• Anicteric or silent infection is common in young children with HAV; Akbar notes fewer than 5% of HAV infections cause recognisable illness.
• Hepatitis B may begin with an immune-complex prodrome: urticaria, rash, arthritis (Nelson).

Extrahepatic features

Laboratory interpretation

Liver tests

Hepatitis A serology

• IgM anti-HAV: acute infection (appears with symptoms, persists about 4 to 6 months).
• IgG anti-HAV: past infection or vaccination; lifelong immunity.
• No carrier state; virus shedding in stool largely stops by the time jaundice appears; children are infectious for about a week after jaundice begins (Akbar).

Hepatitis B serology

Other serology

• HCV: anti-HCV (exposure, not protective) and HCV RNA by PCR (active infection). Maternal anti-HCV can cross the placenta, so antibody cannot confirm infection in infants for the first months (Akbar: up to 15 months).
• HDV: anti-HDV with HBsAg.
• HEV: anti-HEV.

Differential diagnosis

• Other infections: EBV (infectious mononucleosis), CMV, varicella, herpes simplex, adenovirus, leptospirosis, E. coli sepsis
• Drug-induced hepatitis (paracetamol, isoniazid, valproate)
• Wilson disease and autoimmune hepatitis (always consider in a child over 3 with unexplained hepatitis)
• Haemolysis (unconjugated jaundice, normal ALT)
• Biliary obstruction: cholecystitis, choledochal cyst, gallstones
• Pancreatitis, viral enteritis

Management

Supportive (most children)

• Care at home with rest, adequate fluids and a nutritious diet with enough calories.
• Avoid hepatotoxic drugs and sedatives; avoid unnecessary paracetamol in high doses and elective surgery during the illness.
• Corticosteroids are not used in acute viral hepatitis (Akbar notes they are contraindicated in HBV).
• Hygiene: hand washing, safe disposal of stool and nappies (HAV, HEV); avoid sharing blood-contaminated items (HBV, HCV).
• Prolonged cholestasis: fat-soluble vitamins (A, D, E, K) and relief of itching.

Indications for admission (Nelson, Akbar)

• Persistent vomiting and dehydration, unable to take oral fluids
• Prolonged prothrombin time or bleeding
• Any sign of encephalopathy: drowsiness, confusion, irritability, behaviour change
• Hypoglycaemia, deepening jaundice, ascites, shrinking liver
• Very young infants, underlying chronic liver disease, or uncertain diagnosis

Refer to a liver centre

• Signs of acute liver failure (INR rising, encephalopathy): consider liver transplantation.

Chronic HBV and HCV

Treated by specialists (interferon or oral antivirals for HBV; antiviral combinations for HCV). Children with chronic HBV or HCV should be vaccinated against HAV (and HBV for HCV) and screened for liver cancer and cirrhosis.

Complications and prognosis

Prevention

Hygiene

• Safe drinking water, sanitation, hand washing, food hygiene (HAV, HEV).
• Screening blood donors, sterile needles and equipment (HBV, HCV).

Hepatitis A

• HAV vaccine (inactivated, intramuscular, two doses 6 to 12 months apart) from about 12 months to 2 years of age.
• After exposure: vaccine (preferred from 12 months) or immunoglobulin 0.02 mL/kg IM (under 12 months or immunocompromised), within 2 weeks.

Hepatitis B

• Universal infant vaccination, starting at birth; it is part of Pakistan's EPI (check the current national schedule, as it can change).
• Baby of an HBsAg-positive mother: give HBIG 0.5 mL together with the first HBV vaccine dose, within the first 12 hours, then complete the vaccine course; check the infant's HBsAg and anti-HBs status at about 9 to 15 months (Nelson). Vaccine plus HBIG prevents about 99% of vertical transmission (Nelson).
• Mother's status unknown: vaccine within 12 hours; give HBIG as soon as she is found positive (no later than 1 week).
• Breastfeeding is not contraindicated.

Hepatitis C and E

• No vaccine for HCV; prevention is by safe blood and injection practice.
• HEV: safe water; protect pregnant women.

Quick revision

• HAV commonest; faeco-oral; IgM anti-HAV; no carrier state.
• A and E: faeco-oral, acute only; B, C, D: blood-borne, chronic possible.
• Prodrome then jaundice, dark urine, pale stools, tender liver; ALT 15 to 20 times normal.
• PT/INR is the best severity guide; hypoglycaemia and drowsiness = liver failure.
• HBsAg first marker; IgM anti-HBc acute and window; anti-HBs = immunity.
• HBV chronic in 90% after perinatal infection.
• Supportive care; admit for vomiting, dehydration, prolonged PT, encephalopathy.
• Newborn of HBsAg-positive mother: vaccine plus HBIG 0.5 mL, both inside the first 12 hours.

Written by The House Job from standard references (Basis of Paediatrics by Pervez Akbar; Nelson Essentials of Paediatrics).

FAQ