diease

Hepatitis


Hepatitis overview and Definition

Hepatitis is a condition that causes inflammation of the liver. The swelling causes inflammatory responses that may cause elevation in liver enzymes and results in damage to liver. Hepatitis can be an acute or chronic.  It can be caused by infection or chemical induced or autoimmune regulated.

A.Clinical Clarification/Definition

Hepatitis is defined as the inflammation of liver parenchyma.

Inflammation is defined as swelling that occurs when tissues of the body are injured or infected.

B.Classification

 a.Infectious hepatitis – this type is caused mainly by infections

  1. More commonly due to hepatitis A, B, C, D, and E
  2. Rarely due to herpes simplex virus and yellow fever
  3. Less commonly due to cytomegalovirus, and Epstein Barr virus

b.Radiation hepatitis – radiation weakens immunity thus may result in co infection with other viral infections that may result in inflammation of liver

c.Drug induced hepatitis

d.Alcoholic and non-alcoholic induced hepatitis

e.Cholestatic hepatitis

f.Autoimmune hepatitis – it is caused in conditions associated with Positive antinuclear antibody and smooth muscle antibody

g.Other

  1. Wilsons’s disease
  2. Pregnancy

 

C.Epidemiology:

Viral Hepatitis is the most common type of hepatitis. It is most often cause of epidemics. Spread of infection is mainly by the fecal - oral route and due to ingestion of contaminated food or water and sexual interactions.

Drug induced hepatitis has an estimated annual incidence between 15 person every 1,00,000 persons exposed to drugs. Any drug that may be used to treat any condition prescribed or availed over the counter taken over a prolonged period of time or increased dosage may result in inflammation of hepatitis.

Autoimmune diseases cause hepatitis have an incidence rate of 2 person every 1,00,000 people with any autoimmune conditions which may be hereditary or acquired.


Pathophysiology

The pathway of viral hepatitis is by activation of apoptosis also called as cell death by activating innate and adaptive the immune system leading to an inflammatory response. Depending on the strength of the immune response, types of immune cells involved and ability of virus to protect itself. Infection leads to acute disease or chronic disease. The chronic presence of virus within liver cells results in multiple waves of inflammation, injury and wound healing that leads to scarring or fibrosis. It may lead to hepatocellular carcinoma. In chronic Hepatitis B and C, natural killer cell function is impaired thus leads to further destruction and decline in hepatocyte functions.

The accumulation of free fatty acids and breakdown products in the liver cells causes steatosis. This reversible process impacts the hepatocyte's ability to maintain lipid homeostasis leading to accumulation of toxic substances and fat globules. On prolonged exposure the abnormal lipid deposition triggers immune system through toll-like receptor 4 that results in production of inflammatory cytokines like TNF and cause liver cell injury and death. They result in formation of fibrosis that led to cirrhosis and hepatocellular carcinoma.


Clinical signs & symptoms

Symptoms of acute stage: Fever, Fatigue, Loss of appetite, Nausea and/or vomiting, Abdominal pain, Dark urine, Clay-colored bowel movements, Joint pain, Jaundice, yellowing of your skin and eyes

Symptoms of chronic stage: hepatosplenomegaly, serositis, suppression of bone marrow, confusion, disorientation, delirium, sepsis, hirsutism, amenorrhea and renal failure

At acute stage symptoms start anywhere between 2 weeks to 6 months since exposure.

At chronic stage symptoms start when prolonged above 6 months.


Differential Diagnosis

1.Clinical Examination/tests

  • General – fever, night sweats
  • Skin – icteric skin, urticaria rash in skin
  • Oral cavity – yellowing mucosa of oral cavity
  • Eyes – icteric sclera
  • Neurological – Dementia, mental confusion, coma
  • Abdomen cavity – hepatosplenomegaly, lymph node enlargement

2.Laboratory tests 

 

  • Detecting IgM levels of various hepatitis A,B,C,D and E infection

The following tests are done after confirmation of HEPATITIS markers,

 

  • white blood cell count is normal to low
  • leukopenia with a relative lymphocytosis
  • Mild proteinuria is common
  • elevated AST or ALT occurs early followed by elevations of bilirubin and alkaline phosphatase
  • increase in urinary urobilinogen. A Prodromal stage; the serum bilirubin is usually normal.
  • Coombs’-positive haemolytic anaemia or aplastic anaemia.
  • prothrombin time (PT) is prolonged in severe cases.
  • erythrocyte sedimentation rate is raised.

3.Imaging

  • ULTRASOUND

           hepatomegaly - most sensitive sign

           gallbladder wall thickening

           periportal edema

           accentuated brightness of portal vein radicle walls

  • CT

           Hepatomegaly

           periportal edema

           diffuse edematous change

           possible periportal/hepatoduodenal lymphadenopathy

  • MRI

          periportal edema

          periportal enhancement

          hepatic steatosis

  • ERCP

          acalculous cholecystitis

          cholangitis

DIFFERENTIAL DIAGNOSIS:

Other infections like infectious mononucleosis, cytomegalovirus infection, herpes simplex virus infection, leptospirosis, secondary syphilis, brucellosis, Q fever, malaria

 

 


Prognosis

In case of viral hepatitis, The prognosis is good with complete recovery. The mortality in young adults is 0.1% but it increases with age. Death is due to fulminant hepatic necrosis. During recovery 5–15% of patients have relapse hepatitis. Acute liver failure complicates acute hepatitis A in only 0.1% of cases.

COMPLICATIONS of HEPATITIS:

  • Fulminant hepatitis
  • Pancreatitis
  • Aplastic anemia
  • Peripheral neuropathy
  • Myocarditis
  • Superinfection and Co-infection
  • Liver failure
  • Encephalopathy


Prevention

There are different methods to prevent hepatitis which depends on the type of hepatitis. Although Autoimmune hepatitis cannot be prevented.

  

  • Control of hepatitis depends on good hygiene.
  • improve social conditions like overcrowding and poor sanitation.
  • active immunisation with inactivated virus vaccine. A single dose produces antibodies that persist for at least 1 year and the immunity lasts for 10 years
  • Immune serum globulin is effective in an outbreak of hepatitis as injection of those at risk prevents secondary spread to their families.
  • People travelling to endemic areas are best protected by vaccination
  • The virus is resistant to chlorination but it is killed by boiling water for 10 minutes
  •  wash hands before intake of food
  • Avoid regular intake of alcohol