What is A 19-year-old male presents with a 1-week history of malaise and anorexia followed by fever and sore throat. On physical examination, the throat is inflamed without exudate. There are a few palatal petechiae. Cervical adenopathy is present. The liver is percussed at 12 cm and the spleen is palpable. The throat culture is negative for group A streptococci and peripheral blood smears show atypical lymphocytosis. Hb: 12 g/dL, Reticulocytes: 4% WBC: 14,000/uL with 60% Lymphocytes Bilirubin total: 2.0 mg/dL (normal 0.2 to 1.2) Lactic dehydrogenase (LDH) serum: 260 IU/L (normal 20 to 220) Aspaate (AST): 40 U/L (normal 8 to 20 U/L) Alanine (ALT): 35 U/L (normal 8 to 20 U/L) The next best investigation modality would be: and explain in detail?
(Braunwald, 15/e, pp 1109-1111.) This young man presents with classic signs and symptoms of infectious Mononucleosis. In a young patient with fever, pharyngitis, lymphadenopathy, and lymphocytosis, the peripheral blood smear should be evaluated for atypical lymphocytes. A heterophile antibody test should be performed. The symptoms described in association with atypical lymphocytes and a Positive heterophile test is usually due to Epstein- Barr virus. Neither liver biopsy nor lymph node biopsy is necessary. Workup for toxoplasmosis or cytomegalovirus infection or hepatitis B and C would be considered in heterophile-negative patients, Hepatitis does not occur in the setting of rheumatic fever, and an antistreptolysin O titer is not indicated. Coicosteroids are indicated in the treatment of infectious mononucleosis when severe hemolytic anemia is demonstrated or when airway Obstruction occurs. Neither fatigue nor the complication of hepatitis is an indication for coicosteroid therapy.