Acute Hepatitis B is the Cause
Based on the serologic profile showing HBsAg positive and anti-HBc positive (presumed total anti-HBc, which includes IgM), this patient has acute hepatitis B infection causing the acute symptoms. The answer is D (Hepatitis B).
Serologic Interpretation
The key to diagnosing acute versus chronic hepatitis B lies in understanding the serologic markers 1, 2:
- HBsAg positive indicates active HBV infection (either acute or chronic) 1
- Anti-HBc positive (when IgM anti-HBc is present) confirms acute infection 2
- Anti-HBs positive in the presence of HBsAg is unusual but can occur during seroconversion or in certain clinical scenarios 1
The critical distinguishing marker is IgM anti-HBc, which appears at the onset of symptoms in acute HBV infection and persists for up to 6 months if the infection resolves 2. This is the most reliable marker for distinguishing acute from chronic HBV infection 2.
Why This is Acute Hepatitis B
The clinical presentation of acute hepatitis with the following serologic pattern indicates acute HBV 1:
- Symptomatic acute hepatitis occurs in 30-50% of persons aged >5 years after HBV infection 1
- Typical symptoms include fatigue, poor appetite, nausea, vomiting, abdominal pain, low-grade fever, jaundice, dark urine, and light stool color 1
- Acute illness typically lasts 2-4 months 1
Why Not the Other Options
Hepatitis A (Option A): The HAV IgM is negative, ruling out acute hepatitis A infection 1. HAV IgM becomes positive 5-10 days before symptom onset and remains positive for 6-12 months 1.
Hepatitis C (Option B): Not mentioned in the laboratory panel, and the positive HBV markers clearly indicate HBV as the cause 3.
Critical Clinical Considerations
Immediate Management Priorities
- No specific antiviral treatment is required for acute hepatitis B as the vast majority of adults (>95%) resolve the infection spontaneously 4
- Supportive care is the mainstay of therapy 2
- Monitor for progression to acute liver failure, which occurs in approximately 1% of cases 1, 4
When to Consider Antiviral Therapy
Oral anti-HBV agents should be considered only if the patient develops signs of acute liver failure 4. Signs include:
- Prolonged prothrombin time
- Hepatic encephalopathy
- Severe coagulopathy
- Rising bilirubin despite falling transaminases 5
Essential Follow-up
- Monitor hepatic function closely with clinical and laboratory follow-up for at least several months 6
- Assess for resolution versus progression to chronic infection (<5% risk in adults) 2, 3
- Screen and vaccinate close contacts if they are susceptible 2
Common Pitfall to Avoid
Do not confuse the presence of anti-HBs with immunity in this context 1. While anti-HBs typically indicates immunity or recovery, its presence alongside HBsAg in an acutely ill patient likely represents early seroconversion or a mixed serologic picture during acute infection 1. The positive HBsAg with acute symptoms confirms active infection 1, 2.