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Hepatitis is liver disease characterised by the presence of immune cells within the liver.
Viral Hepatitis
Many viruses are able to infect the liver, some of these will only affect the liver, whilst others may be systemic.
Hepatitis viruses A-E +G will primarily affect the liver.
Systemic viruses that will affect the liver include:
- Herpes viruses
- Epstein – Barr Virus (EBV)
- Cytomegalovirus (CMV)
- Varicella virus
- Adenovirus
- Yellow fever
- Haemorrhagic viruses
General effects after infection with a hepatitis virus
The most commonly recognised sign is an acute attack with icteric effects. Most people will make a complete recovery. Symptoms may last a few days to a couple of weeks, and include:
- Fever
- Malaise
- Upper abdominal discomfort
- Jaundice – often lasts a few days to a few weeks and then subsides. It is also one of the last symptoms to develop – it may not develop until 2 weeks after other symptoms, or indeed may not develop at all (anicteric hepatitis).
- Symptoms usually last 3-6 weeks and then subside.
- Development of ascites and oedema is very uncommon, but can still occur in the most serious cases.
- The disease may have several ‘waves’ where the patient has several episodes of worsening symptoms before they make a full recovery
- With some viruses (B, C &D) there is a chance of developing chronic disease.
- Very few people die from acute viral hepatitis.
- Fulminant liver failure can very rarely occur. The term ‘fulminant’ means the failure occurs very suddenly and is severe, but it is reversible. Technically, fulminant liver disease is where there is severe encephalopathy that develops within 2 weeks of the onset of jaundice.
Clinical examination
Some or all of the following features may be present:
- Spider naevi (these will disappear after recovery). Up to 5 of these are normal – it is only when you have more that they suggest a pathological cause.
- Jaundice
- RUQ tenderness.
- Mild hepatomegaly – although in fulminant liver failure the liver will shrink rapidly.
- Splenomegaly is uncommon, and suggests either underlying pre-existing liver disease, or perhaps infection with a different virus, such as Epstein Barr, or cytomegalovirus.
- Persistent nausea and vomiting suggest severe hepatitis, and these increase the risk of hypoglycaemia.
- Hepatic encephalopathy, although rare, indicates the severity of the disease – basically indicating liver failure.
Investigations
- The general pattern of the LFT results will be hepatic. (see liver tests notes for explanation)
- The white cell count is usually normal but will show a degree of lymphocytosis
- This means that the lymphocytes (which normally make up 20-40% of all circulating WBC’s) will be raised in proportion to the normal white cell count.
- You should perform tests for the various indicators of each type of virus.
Differential diagnosis
The symptoms of Drug induced hepatitis are the most similar. This is particularly true if the history includes a use of NSAID’s or acetaminophen. Mushroom poisoning is also a situation that will produce very similar symptoms.
1/3 of autoimmune hepatitis patients will present acutely in a manner similar to that of viral hepatitis.
Acute fatty liver is a disease that occurs in pregnancy (and also other situations) and can be very serious. It is in fact even less common than hepatitis in pregnancy.
Viral hepatitis is a common cause of jaundice, and should be considered in anyone presenting with high serum transaminases.
It is also important to remember that often the disease may be anicteric (no jaundice present).
Generally there is no treatment for acute attacks of hepatitis.
Chronic hepatitis does require treatment.
They are all RNA viruses, except hep B which is DNA. They all cause cell death directly, except hep B where the hepatocytes are killed by your own T- cells.