Overview of Hepatitis: Hepatitis: Merck Manual Professional

Hepatic and Biliary Disorders

Overview of Hepatitis

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Overview of Hepatitis

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Hepatitis is an inflammation of the liver characterized by diffuse or patchy necrosis. Major causes are specific hepatitis viruses, alcohol, and drugs (eg, isoniazidSome Trade Names
INH
NYDRAZID
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). Less common causes include other viral infections (eg, infectious mononucleosis, yellow fever, cytomegalovirus infection) and leptospirosis. Parasitic infections (eg, schistosomiasis, malaria, amebiasis), pyogenic infections, and abscesses that affect the liver are not considered hepatitis. Liver involvement with TB and other granulomatous infiltrations is sometimes called granulomatous hepatitis, but the clinical, biochemical, and histologic features differ from those of diffuse hepatitis.

Various systemic infections and other illnesses may produce small focal areas of hepatic inflammation or necrosis. This nonspecific reactive hepatitis can cause minor liver function abnormalities but is usually asymptomatic.

Some types of infectious and noninfectious liver inflammation are summarized in Table 1: Hepatitis: Selected Diseases or Organisms Associated With Liver Inflammation.

Table 1

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Selected Diseases or Organisms Associated With Liver Inflammation
Disease or Organism	Manifestations
Viruses
Cytomegalovirus	In neonates: Hepatomegaly, jaundice, congenital defects In adults: Mononucleosis-like illness with hepatitis; may occur posttransfusion
Epstein-Barr	Infectious mononucleosis Clinical hepatitis with jaundice in 5–10%; subclinical liver involvement in 90–95% Acute hepatitis sometimes severe in young adults
Yellow fever	Jaundice, systemic toxicity, bleeding Liver necrosis with little inflammatory reaction
Other	Hepatic infection occasionally due to echovirus or coxsackievirus infections, varicella, herpes simplex, rubella, or rubeola
Bacteria
Actinomycosis	Granulomatous reaction of liver with progressive necrotizing abscesses
Pyogenic abscess*	Serious infection acquired via portal pyemia, cholangitis, or hematogenous or direct spread; due to various organisms, especially gram-negative and anaerobic Illness and toxicity, yet only mild liver dysfunction
Tuberculosis	Hepatic involvement (common; usually subclinical) with granulomatous infiltration; jaundice (rare) Disproportionately increased alkaline phosphatase
Other	Minor focal hepatitis in numerous systemic infections (common; usually subclinical)
Fungi
Histoplasmosis	Granulomas in liver and spleen (usually subclinical) that heal with calcification
Other	Granulomatous infiltration sometimes occurring in cryptococcosis, coccidioidomycosis, blastomycosis, or other infections
Protozoa
Amebiasis*	Important disease, often without obvious dysentery Usually a large single abscess with liquefaction Systemic illness, tender hepatomegaly, surprisingly mild liver dysfunction
Malaria	A common cause of hepatosplenomegaly in endemic areas Jaundice absent or mild unless active hemolysis is present
Toxoplasmosis	Transplacental infection In neonates: Jaundice, CNS and other systemic manifestations
Visceral leishmaniasis	Infiltration of reticuloendothelial system by parasite, hepatosplenomegaly
Helminths
Ascariasis	Biliary obstruction by adult worms, parenchymal granulomas caused by larvae
Clonorchiasis	Biliary tract infestation, cholangitis, stones, cholangiocarcinoma
Echinococcosis	One or more hydatid cysts, which usually have a calcified rim and may be large but which often are asymptomatic and do not disrupt liver function Can rupture into the peritoneum or biliary tract
Fascioliasis	Acute: Tender hepatomegaly, fever, eosinophilia Chronic: Biliary fibrosis, cholangitis
Schistosomiasis	Periportal granulomatous reaction to ova with progressive hepatosplenomegaly, pipestem fibrosis, portal hypertension, and varices Hepatocellular function preserved; not true cirrhosis
Toxocariasis	Visceral larva migrans syndrome Hepatomegaly with granulomas, eosinophilia
Spirochetes
Leptospirosis	Acute fever, prostration, jaundice, bleeding, renal injury Liver necrosis (often mild despite severe jaundice)
Syphilis	Congenital: Neonatal hepatosplenomegaly, fibrosis Acquired: Variable hepatitis in secondary stage, gummas with irregular scarring in tertiary stage
Relapsing fever	Borrelia infection Systemic symptoms, hepatomegaly, sometimes jaundice
Unknown
Idiopathic granulomatous hepatitis	Active chronic granulomatous inflammation not resulting from known causes (sarcoid variant?) May cause mainly systemic symptoms (eg, fever, malaise) and can occur when certain drugs are used
Sarcoidosis	Granulomatous infiltration (common, usually subclinical), jaundice (rare) Occasionally, progressive inflammation with scarring and portal hypertension
Ulcerative colitis, Crohn disease	Spectrum of hepatic disease, especially in ulcerative colitis; includes periportal inflammation (pericholangitis), sclerosing cholangitis, cholangiocarcinoma, and autoimmune hepatitis Poor correlation between hepatic function and activity of bowel disorder
*Differentiate from amebiasis with serologic tests for amebas and direct percutaneous abscess aspiration.

Selected Diseases or Organisms Associated With Liver Inflammation

Disease or Organism

Manifestations

Viruses
Cytomegalovirus	In neonates: Hepatomegaly, jaundice, congenital defects In adults: Mononucleosis-like illness with hepatitis; may occur posttransfusion
Epstein-Barr	Infectious mononucleosis Clinical hepatitis with jaundice in 5–10%; subclinical liver involvement in 90–95% Acute hepatitis sometimes severe in young adults
Yellow fever	Jaundice, systemic toxicity, bleeding Liver necrosis with little inflammatory reaction
Other	Hepatic infection occasionally due to echovirus or coxsackievirus infections, varicella, herpes simplex, rubella, or rubeola
Bacteria
Actinomycosis	Granulomatous reaction of liver with progressive necrotizing abscesses
Pyogenic abscess*	Serious infection acquired via portal pyemia, cholangitis, or hematogenous or direct spread; due to various organisms, especially gram-negative and anaerobic Illness and toxicity, yet only mild liver dysfunction
Tuberculosis	Hepatic involvement (common; usually subclinical) with granulomatous infiltration; jaundice (rare) Disproportionately increased alkaline phosphatase
Other	Minor focal hepatitis in numerous systemic infections (common; usually subclinical)
Fungi
Histoplasmosis	Granulomas in liver and spleen (usually subclinical) that heal with calcification
Other	Granulomatous infiltration sometimes occurring in cryptococcosis, coccidioidomycosis, blastomycosis, or other infections
Protozoa
Amebiasis*	Important disease, often without obvious dysentery Usually a large single abscess with liquefaction Systemic illness, tender hepatomegaly, surprisingly mild liver dysfunction
Malaria	A common cause of hepatosplenomegaly in endemic areas Jaundice absent or mild unless active hemolysis is present
Toxoplasmosis	Transplacental infection In neonates: Jaundice, CNS and other systemic manifestations
Visceral leishmaniasis	Infiltration of reticuloendothelial system by parasite, hepatosplenomegaly
Helminths
Ascariasis	Biliary obstruction by adult worms, parenchymal granulomas caused by larvae
Clonorchiasis	Biliary tract infestation, cholangitis, stones, cholangiocarcinoma
Echinococcosis	One or more hydatid cysts, which usually have a calcified rim and may be large but which often are asymptomatic and do not disrupt liver function Can rupture into the peritoneum or biliary tract
Fascioliasis	Acute: Tender hepatomegaly, fever, eosinophilia Chronic: Biliary fibrosis, cholangitis
Schistosomiasis	Periportal granulomatous reaction to ova with progressive hepatosplenomegaly, pipestem fibrosis, portal hypertension, and varices Hepatocellular function preserved; not true cirrhosis
Toxocariasis	Visceral larva migrans syndrome Hepatomegaly with granulomas, eosinophilia
Spirochetes
Leptospirosis	Acute fever, prostration, jaundice, bleeding, renal injury Liver necrosis (often mild despite severe jaundice)
Syphilis	Congenital: Neonatal hepatosplenomegaly, fibrosis Acquired: Variable hepatitis in secondary stage, gummas with irregular scarring in tertiary stage
Relapsing fever	Borrelia infection Systemic symptoms, hepatomegaly, sometimes jaundice
Unknown
Idiopathic granulomatous hepatitis	Active chronic granulomatous inflammation not resulting from known causes (sarcoid variant?) May cause mainly systemic symptoms (eg, fever, malaise) and can occur when certain drugs are used
Sarcoidosis	Granulomatous infiltration (common, usually subclinical), jaundice (rare) Occasionally, progressive inflammation with scarring and portal hypertension
Ulcerative colitis, Crohn disease	Spectrum of hepatic disease, especially in ulcerative colitis; includes periportal inflammation (pericholangitis), sclerosing cholangitis, cholangiocarcinoma, and autoimmune hepatitis Poor correlation between hepatic function and activity of bowel disorder
*Differentiate from amebiasis with serologic tests for amebas and direct percutaneous abscess aspiration.

Last full review/revision March 2013 by Anna E. Rutherford, MD, MPH

Content last modified March 2013

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