A 31-year-old man comes to the physician after experiencing a week of generalized weakness, decreased appetite, and nausea. He is an intravenous drug user enrolled in a methadone program but has relapsed due to family problems. The patient was hospitalized for aspiration pneumonia 2 years ago. He does not use alcohol or prescription or over-the-counter medications. The patient's temperature is 37.2 C (99 F), blood pressure is 114/78 mm Hg, and pulse is 88/min. Examination shows mild tenderness in the right upper quadrant. Laboratory results are as follows: Which of the following is most likely to indicate the diagnosis in this patient?

Question

A 31-year-old man comes to the physician after experiencing a week of generalized weakness, decreased appetite, and nausea.  He is an intravenous drug user enrolled in a methadone program but has relapsed due to family problems.  The patient was hospitalized for aspiration pneumonia 2 years ago.  He does not use alcohol or prescription or over-the-counter medications.  The patient's temperature is 37.2 C (99 F), blood pressure is 114/78 mm Hg, and pulse is 88/min.  Examination shows mild tenderness in the right upper quadrant.  Laboratory results are as follows:  Which of the following is most likely to indicate the diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c172_80fe_8f63_1d252baec254_MD0005_00 This patient's right upper quadrant pain, elevated bilirubin, and markedly elevated aminotransferase levels suggest acute hepatitis. His intravenous (IV) drug use history places him at higher risk for hepatitis B or C. Acute hepatitis C virus (HCV) infection can develop 2−26 weeks after viral exposure. Most patients with acute HCV are asymptomatic. Symptomatic patients typically develop malaise, nausea, jaundice, and right upper quadrant pain that can last for 2−12 weeks. Laboratory studies usually show elevated aminotransferase levels that can be 10−20 times the upper limit. Most patients develop anti-HCV antibodies 2−6 months after exposure. HCV ribonucleic acid (RNA) can generally first be detected within days to 8 weeks following viral exposure. This patient has negative anti-HCV antibodies, but he may not have formed anti-HCV antibodies yet. As a result, he requires testing for HCV RNA by polymerase chain reaction (PCR) to document acute HCV infection. Hepatitis A is typically transmitted by a fecal-oral route, and the negative anti-hepatitis A virus (anti-HAV) antibodies in this patient make hepatitis A less likely. This patient's negative hepatitis B surface antigen (HBsAg) and anti-HBsAg antibodies make hepatitis B also less likely. A window period may exist with both negative HBsAg and anti-HBsAg antibodies, but this typically occurs after resolution of a patient's symptoms and elevated liver function test results. (Choice A) Radiologic imaging is not needed to diagnose acute HCV infection. Imaging can be useful in diagnosing biliary disease (eg, choledocholithiasis), but this patient's normal alkaline phosphatase level makes biliary disease less likely. Abdominal ultrasonography (rather than CT) is usually the first imaging modality used. (Choice B) Antinuclear antibodies results are helpful for suspected autoimmune hepatitis, but this patient's IV drug use makes viral hepatitis more likely. (Choice D) A Monospot test helps diagnose infectious mononucleosis, which typically presents with fatigue, pharyngitis, lymphadenopathy, splenomegaly, and atypical lymphocytosis. Patients can have elevated liver function test results, although usually not to the extent seen in this patient. In addition, this patient's history of IV drug use makes viral hepatitis more likely. (Choice E) Elevated serum ferritin may be helpful for confirming hemochromatosis in patients with a history of multiple blood transfusions or a family history of hemochromatosis. Educational objective: Acute hepatitis C virus (HCV) infection is frequently asymptomatic but can present with malaise, nausea, right upper-quadrant pain, and abnormal liver function test results. It is important to maintain a high degree of suspicion for HCV in patients with risk factors. Diagnosis is confirmed with HCV ribonucleic acid detection by polymerase chain reaction testing as anti-HCV antibodies can take up to 12 weeks or longer to become positive in acute HCV. References: Diagnosis of acute hepatitis C virus infection and estimated incidence in low- and high-risk English populations. (http://www.ncbi.nlm.nih.gov/pubmed/18637073) Diagnosis and treatment of acute hepatitis C virus infection. (http://www.ncbi.nlm.nih.gov/pubmed/23083829) Acute hepatitis C. (http://www.ncbi.nlm.nih.gov/pubmed/18657711)

A 31-Year-Old Man Comes to the Physician After Experiencing a Week