hepatitis

introduction

causes of hepatitis

ethanol (alcohol and alcohol withdrawal)
steatohepatitis (fatty liver)
viral
- hepatitis A
  - is a picornavirus that is resistant to many environmental factors (eg, temperature, certain chemicals) and is mainly transmitted by the faecal-oral route, and accounts for a third of all new cases of acute viral hepatitis in USA.
  - see hepatitis A
- hepatitis B
  - belongs to the hepadna viruses. Hepatitis B virus is responsible for almost half of the cases of acute viral hepatitis cases reported in the United States. Highest rate of acute infection in USA occurred in patients aged 25-44 years in 2006.
  - one of the main causes of cirrhosis and hepatocellular carcinoma
  - see hepatitis B virus
- hepatitis C
  - a single-stranded ribonucleic acid (RNA) virus that is the most frequent cause of parenteral non-A, non-B hepatitis worldwide. It causes 20% of acute viral hepatitis cases in USA.
  - one of the main causes of cirrhosis and hepatocellular carcinoma
  - chronic infection also associated with sporadic form of porphyria cutanea tarda.
  - see hepatitis C virus
- hepatitis D
  - a defective, single-stranded RNA virus that requires the presence of hepatitis B virus to replicate.
  - ~4% of cases of acute hepatitis B virus in the US are thought to involve co-infection with hepatitis D virus
- hepatitis E
  - the primary cause of enterically transmitted non-A, non-B hepatitis; most outbreaks occur in developing countries.
  - zoonotic risk from eating under-cooked pork or wild boars in Europe
  - see hepatitis E viruses (HEV)
- hepatitis G
  - characterized in 1996, is associated with acute and chronic liver disease, but studies have not clearly implicated hepatitis G virus as an etiologic agent of hepatitis. It is transmitted through blood and blood products.
- severe, non A-E hepatitis
  - usually occurs mainly in children under 5yrs and pathogen is yet to be isolated
  - Victoria usually has 5-6 cases per year with 1-2 needing a transplant
  - in 2022, an outbreak initially in Europe of childhood hepatitis seems to be spreading globally and ~10% need transplants
- other viral infections may cause mild hepatitis such as:
  - infectious mononucleosis
  - cmv
drug-induced hepatotoxicity:
- more than 900 drugs, toxins, and herbs have been reported to cause drug induced liver injury (DILI).
- drugs account for 20-40% of all instances of fulminant hepatic failure
  - in Western cultures, most result from paracetamol in acute over-dosage
  - protein shakes containing green tea extracts have caused acute fulminant liver failure
  - in China, drug-induced hepatotoxicity was the cause of 44% of cases of acute liver failure, and of drug-induced ALF, 38% due to traditional Chinese medicines, 27% due to paracetamol overdose, 14% due to antibiotics ¹⁾
- common medications causing DILI:
  - paracetamol (acetaminophen) - even 4g/d for 2wks can transiently triple LFTs
  - traditional Chinese medicines (herbs)
  - non-steroidal anti-inflammatory drugs (NSAIDs)
  - statins
  - penicillins especially flucloxacillin if > 14 days Rx and genetic susceptibility
  - trimethoprim/sulfamethoxazole
  - rifampicin
  - herbal medicines
  - chlopromazine
  - isoniazid
  - methotrexate
  - sodium valproate (Epilim)
  - amiodarone
  - antiretrovirals
  - cholestatic picture
    - amoxicillin/clavulonic acid
    - erythromycin
    - nitrofurantoin
    - rifampicin
    - antidepressants esp. duloxetine, mirtazapine, tricyclic antidepressants
    - clopidogrel
  - in 2013, US FDA began investigating a sports supplement, OxyElite Pro in relation to several hepatitis cases including one death²⁾
- see also Emedicine

biliary obstruction

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PLOS ONE November 2013 | Volume 8 | Issue 11 | e80991

²⁾

http://www.acem.org.au/sitedocument.aspx?docId=1297