### Date : 2024-11-20 15:35
### Topic : Hepatitis #gastroenterology
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### **Hepatitis**
**Hepatitis** refers to **inflammation of the liver**, which can result from infections, toxins, autoimmune conditions, or other diseases. It can lead to liver dysfunction, ranging from mild, reversible inflammation to severe liver failure or chronic liver disease.
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### **Causes of Hepatitis**
#### **1. Infectious Causes**
- **Viral Hepatitis**:
- **Hepatitis A (HAV)**: Fecal-oral transmission; self-limiting.
- **Hepatitis B (HBV)**: Bloodborne, sexual, and perinatal transmission; may lead to chronic hepatitis.
- **Hepatitis C (HCV)**: Bloodborne transmission; high risk of chronic infection.
- **Hepatitis D (HDV)**: Requires co-infection with HBV.
- **Hepatitis E (HEV)**: Fecal-oral transmission; common in resource-limited areas.
- **Non-Hepatitis Viruses**:
- Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV).
#### **2. Non-Infectious Causes**
- **Alcoholic Hepatitis**:
- Chronic alcohol use damages hepatocytes, leading to inflammation.
- **Drug-Induced Hepatitis**:
- Acetaminophen overdose or long-term use of hepatotoxic drugs.
- **Autoimmune Hepatitis**:
- Immune system attacks liver cells; associated with other autoimmune conditions.
- **Non-Alcoholic Steatohepatitis (NASH)**:
- Related to metabolic syndrome, obesity, diabetes.
#### **3. Other Causes**
- Toxins (e.g., aflatoxins).
- Ischemic hepatitis (due to hypoperfusion).
- Wilson’s disease (copper overload), hemochromatosis (iron overload).
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### **Types of Hepatitis**
| **Type** | **Transmission** | **Acute/Chronic** | **Notes** |
|--------------------|-----------------------------|-------------------------|------------------------------------------|
| **Hepatitis A** | Fecal-oral | Acute only | Vaccine available; self-limiting. |
| **Hepatitis B** | Bloodborne, sexual, perinatal | Both acute and chronic | Vaccine available; chronic infection risk. |
| **Hepatitis C** | Bloodborne | Primarily chronic | High chronicity; curable with antivirals. |
| **Hepatitis D** | Bloodborne | Chronic (needs HBV) | Requires HBV co-infection. |
| **Hepatitis E** | Fecal-oral | Acute (chronic rare) | Severe in pregnancy; common in outbreaks.|
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### **Clinical Presentation**
#### **Symptoms**:
1. **Acute Hepatitis**:
- Fatigue, malaise, anorexia, nausea, vomiting.
- **Jaundice**: Yellowing of skin and eyes due to hyperbilirubinemia.
- Dark urine, pale stools, pruritus.
- Right upper quadrant abdominal pain.
2. **Chronic Hepatitis** (lasting >6 months):
- Often asymptomatic in early stages.
- May progress to signs of **cirrhosis** or **liver failure**:
- Ascites, encephalopathy, bleeding, spider angiomas.
#### **Physical Exam**:
- Hepatomegaly, jaundice, tenderness in the right upper quadrant.
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### **Diagnosis**
#### **1. Laboratory Tests**
- **Liver Function Tests (LFTs)**:
- Elevated **ALT** and **AST**: Indicate hepatocyte injury.
- Elevated **bilirubin**: Jaundice and cholestasis.
- Elevated alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT): Suggest cholestasis.
- **Serologic Markers** (for viral hepatitis):
- **HAV IgM**: Acute hepatitis A.
- **HBsAg**: Hepatitis B surface antigen (active infection).
- **Anti-HCV** and **HCV RNA**: Hepatitis C.
- **Autoimmune Markers**:
- Antinuclear antibody (ANA), anti-smooth muscle antibody.
- **Coagulation Tests**:
- Prolonged prothrombin time (PT) indicates liver dysfunction.
#### **2. Imaging Studies**
- **Ultrasound**:
- Detects hepatomegaly, fatty liver, or fibrosis.
- **CT/MRI**:
- Used for complications like tumors or abscesses.
#### **3. Liver Biopsy**
- Confirms diagnosis and assesses severity (e.g., fibrosis, cirrhosis).
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### **Treatment**
#### **1. Supportive Care**:
- For acute hepatitis (e.g., HAV, HEV): Rest, hydration, nutrition.
- Avoid hepatotoxic substances (e.g., alcohol, certain drugs).
#### **2. Antiviral Therapy**:
- **HBV**:
- Chronic infection: Tenofovir, entecavir.
- **HCV**:
- Direct-acting antivirals (DAAs) like sofosbuvir, ledipasvir (high cure rates).
- **HDV**:
- Interferon-based therapy (limited efficacy).
#### **3. Autoimmune Hepatitis**:
- Corticosteroids (e.g., prednisone) and/or azathioprine.
#### **4. Alcoholic Hepatitis**:
- Stop alcohol intake.
- Severe cases: Corticosteroids or pentoxifylline.
#### **5. Liver Transplantation**:
- For end-stage liver disease or fulminant hepatic failure.
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### **Complications**
1. **Acute Complications**:
- Fulminant hepatitis: Rapid liver failure with encephalopathy and coagulopathy.
2. **Chronic Complications**:
- **Cirrhosis**: Irreversible scarring of the liver.
- **Hepatocellular Carcinoma (HCC)**:
- Particularly in chronic HBV and HCV.
- Portal hypertension, ascites, variceal bleeding.
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### **Prevention**
#### **1. Vaccination**:
- **Hepatitis A and B vaccines** are highly effective.
- No vaccines currently for HCV, HDV, or HEV.
#### **2. Lifestyle and Precautions**:
- Avoid contaminated food and water (HAV, HEV).
- Safe sex practices, proper needle disposal, and blood safety (HBV, HCV).
- Limit alcohol intake to prevent alcoholic hepatitis.
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### **Key Points**
- Hepatitis involves liver inflammation with diverse etiologies including viruses (HAV, HBV, HCV), alcohol, and autoimmune diseases.
- **Acute hepatitis** may resolve completely, while **chronic hepatitis** can progress to cirrhosis and liver failure.
- Diagnosis relies on serologic tests, liver function tests, and imaging.
- Treatment is tailored to the cause, ranging from supportive care to antivirals or immunosuppressive therapy.
- Prevention through **vaccination** and lifestyle measures is critical.
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