Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
Hepatitis A and E
Infectious diseases, microbiology and sexual health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Acute liver failure
New encephalopathy, hypoglycaemia, rising INR, bleeding, acidosis, renal injury or rapidly worsening jaundice after acute hepatitis indicates failing hepatic synthetic and detoxification function.
Action: Use ABCDE, check bedside glucose and coagulation immediately, stop non-essential hepatotoxins, treat hypoglycaemia, involve critical care and discuss urgently with a regional liver-transplant centre without waiting for viral results.
Synopsis
Recognise enterically acquired hepatitis A and E, stabilise severe acute hepatitis, interpret time-dependent virology, control transmission, and protect exposed or vulnerable people.
HAV spreads mainly through faeco-oral exposure; HEV acquired in the UK is commonly zoonotic and linked to undercooked pork, offal, wild boar or game.
Both usually cause an acute hepatitic illness with malaise, nausea, anorexia, dark urine, pale stools, pruritus and jaundice, but infection may be asymptomatic.
HAV never becomes chronic; HEV can persist in transplant recipients and other immunosuppressed people and may cause rapid fibrosis.
First assess glucose, INR, cognition, renal function and haemodynamic state because liver failure management must not wait for pathogen confirmation.
Request HAV IgM for recent HAV; combine HEV IgM with HEV RNA when immune impairment, early disease or persistent infection makes antibody testing unreliable.
Most uncomplicated infections need supportive care, alcohol avoidance, medication review and planned biochemical reassessment rather than an antiviral prescription.
Acute infectious hepatitis is notifiable; contact the relevant health-protection team for exclusion, contact tracing, outbreak investigation and HAV post-exposure prophylaxis.
Use current UKHSA criteria for HAV vaccine or human normal immunoglobulin after exposure; no routinely available UK vaccine prevents HEV.
Key red flags
Confusion, drowsiness, asterixis or behavioural change with acute hepatitis is encephalopathy until proved otherwise and needs emergency liver-centre discussion.
INR prolongation, hypoglycaemia, metabolic acidosis, oliguria or lactate elevation marks severe hepatic dysfunction even when aminotransferases begin to fall.
Pregnancy with suspected hepatitis E requires urgent obstetric, infection and hepatology assessment because some imported HEV genotypes carry disproportionate maternal and fetal risk.
Immunosuppression with persistent HEV RNA can progress silently to fibrosis and cirrhosis, so apparent biochemical improvement does not prove clearance.
Intractable vomiting, dehydration, bleeding or inability to maintain intake warrants admission rather than routine community observation.
Jaundice in a food handler, care worker or outbreak setting requires prompt health-protection advice before occupational or contact decisions are made.
Severe synthetic failure
New confusion, low glucose, bruising, rising INR, acidosis or renal dysfunction identifies acute liver failure rather than uncomplicated hepatitis.
Pregnancy vulnerability
Acute jaundice after travel or sanitation exposure during pregnancy needs urgent assessment because severe HEV can deteriorate rapidly.
Investigation priorities
01
Immediate severity bundleFirst step
Identify hepatic failure and complications before virological classification.
Management branches
STABILISETriage acute jaundice
A patient presents with jaundice, dark urine or a markedly hepatitic blood-test pattern.
Assess ABCDE, cognition and hydration, then obtain bedside glucose, INR, renal function, acid-base status and a complete medication and toxin history.
Treat hypoglycaemia immediately, stop non-essential hepatotoxic agents and provide cautious fluid, antiemetic and electrolyte support according to clinical state.
Discuss encephalopathy, progressive coagulopathy, acidosis, renal injury or rapid deterioration urgently with critical care and a liver-transplant centre.
Send pathogen tests and notify suspected acute infectious hepatitis in parallel; neither action should delay physiological stabilisation or referral.
DIAGNOSESeparate HAV from HEV and mimics
The patient is stable enough for cause-directed acute-hepatitis investigation.
Build a dated exposure history covering travel, water, food, pork or game, household illness, sexual practices, occupational setting, transfusion, transplantation and medicines.
Request HAV IgM and HEV serology, adding HEV RNA early when immunosuppression, pregnancy, early sampling or persistent biochemical abnormality raises concern.
Test for alternative viral, toxic, autoimmune, ischaemic and obstructive causes in proportion to severity rather than stopping after the first reactive result.
Key medicines
Hepatitis A vaccine for post-exposure prophylaxisGive one age-appropriate intramuscular dose as soon as possible and within the current UKHSA contact window, then complete the product-specific course if ongoing protection is indicated.Use the current Green Book product, age and immune-status schedule; pregnancy is not an automatic contraindication when exposure risk justifies vaccination, and HNIG may also be indicated for vulnerable contacts.
Human normal immunoglobulin for selected HAV contactsArrange the exact intramuscular product dose through the health-protection and Green Book pathway as soon as possible; do not substitute a locally remembered volume.Supply, timing and eligibility are nationally controlled; review bleeding risk, previous immunoglobulin reaction and interference with subsequent live vaccines.
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
Use the local laboratory or reference service to resolve discordant serology, define RNA follow-up and support outbreak typing when health protection requests it.