CASE 2
A 21-year-old male college student came to the emergency department of a local hospital complaining of fever, headache, and sore throat with severe fatigue and difficulty in swallowing of ten days’ duration.
LABORATORY STUDIES
Diagnostic Work-Up
A clinical diagnosis of infectious mononucleosis (IM) was considered on the basis of the symptoms of fever, sore throat, lymphadenopathy lasting more than 1 week, and the age of the patient. Leukocytosis with lymphocytosis and monocytosis exceeding 50% (including ≥10% atypical cells) are typical signs of IM. Table 2-1 lists the likely causes of illness (differential diagnosis). The investigational approach to delineating the etiology may include
TABLE 2-1 Differential Diagnosis and Rationale for Inclusion (consideration)
Rationale: All of the above may cause pharyngitis. EBV, CMV, and HIV may cause fever, pharyngitis, cervical lymph-adenopathy, atypical lymphocytosis, and hepatosplenomegaly. The remaining organisms are less likely to cause hepato-splenomegaly. S. pyogenes is also less likely to cause atypical lymphocytosis. Adenovirus and HSV-1 often cause pharyngitis, but they are not associated with hepatosplenomegaly. Viral hepatitis is not included because pharyngitis is not a typical feature.
