Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (177 page)

   Disease Manifestations

Viral hepatitis infections may show many and varied clinical features, but most patients with acute viral hepatitis are asymptomatic or experience minimal constitutional symptoms. On the other hand, any of the hepatitis viruses may cause fulminant disease with extensive liver damage and hepatic failure. One cannot distinguish different types of viral hepatitis by clinical features or routine chemistries; specific serologic tests are needed. Hepatitis virus infections demonstrate the following clinical phases.

   Prodromal Phase

   After a variable, virus-specific incubation period, patients may develop non-specific symptoms, including low-grade fever, headache, fatigue and malaise, and arthralgias. Anorexia, nausea, and vomiting are common and may be associated with abdominal pain (epigastric or right upper quadrant).

   Prodromal symptoms typically last 1–2 weeks before the onset of signs and symptoms of acute liver disease. Dark urine may precede the onset of jaundice. Acholic stools may be seen in HAV and HEV infections.

   During the prodrome:

   Specific serologic markers appear in serum (see Figure
5-7
).

   ESR is normal.

   Leukopenia (lymphopenia and neutropenia) is noted with onset of fever, followed by relative lymphocytosis and monocytosis. Plasma cells and <10% atypical lymphocytes may be seen.

   Urinary urobilinogen and total serum bilirubin increase just before the onset of jaundice.

   Serum AST and ALT levels increase during the prodromal phase and show very high peaks (>500 U) during the acute phase.

Figure 5–7
Hepatitis serologic profiles.
A.
Antibody response to hepatitis A.
B.
Hepatitis B core window identification.
C, D.
Hepatitis B chronic carrier profiles: no seroconversion
(C);
late seroconversion
(D).
(Reproduced with permission of Hepatitis Information Center, Abbott Laboratories, Abbott Park, IL).

   Acute Hepatitis Phase