Q&A Medicine>>>>>Infectious Diseases
Question 4#

A 26-year-old man presents to his primary care physician complaining of fatigue, headache, and a sore throat for the past week. There is also nausea and diarrhea, but no weight loss, productive cough, or difficulty breathing. He denies any past medical history, does not take any medications, and has no recent sick contacts. He is sexually active with men and women and uses condoms inconsistently; he drinks alcohol heavily on the weekends and admits to previous IV drug use. On examination, his temperature is 39°C and the rest of his vital signs are normal. He has nontender cervical and axillary lymphadenopathy, tonsillar exudates, and mild splenomegaly. There are also several painful, well-demarcated ulcers within his mouth and a mild maculopapular rash over his chest and arms. A rapid strep test and a monospot (heterophile antibody) test are negative; further screening for chlamydia, gonorrhea, syphilis, and HIV is negative.

What is the most likely diagnosis?

A. Hodgkin lymphoma
B. Acute retroviral syndrome
C. Infectious mononucleosis
D. Secondary syphilis

Correct Answer is B


Acute retroviral syndrome. Acute HIV infection can present in a variety of ways, but typical symptoms of the “acute retroviral syndrome” include a mononucleosis-like syndrome with fever, lymphadenopathy, headache, myalgias/arthralgias, sore throat, and a maculopapular rash. Another less sensitive but more specific finding is painful, well-demarcated mucocutaneous ulcerations. Additional clues to the diagnosis in this case are the patient’s high risk behaviors (unprotected sex, IV drug use) and negative test results for other conditions on the differential diagnosis (mononucleosis due to EBV, syphilis and other STIs, etc.). During the acute phase of HIV infection, there may be a negative screening test (ELISA may take weeks to become positive) with high viral RNA levels. Typically, the diagnosis of HIV is made with a highly sensitive screening test (e.g., ELISA) followed by a more specific confirmatory test (e.g., Western blot).

(A) The finding of diffuse nontender lymphadenopathy is more consistent with a systemic process such as a viral infection rather than Hodgkin lymphoma, which often presents with focal or asymmetric lymphadenopathy. (C) Though heterophile-negative mononucleosis due to CMV is a possibility, the findings of both maculopapular rash and mucocutaneous ulcerations make HIV more likely (both may occur in CMV infection but are less common manifestations, and GI ulcerations usually occur in the setting of immunosuppression). (D) Secondary syphilis is less likely to have mucocutaneous ulcerations and the screening test was negative. Although false negatives are possible with RPR and VDRL tests, the constellation of findings makes HIV infection much more likely than a false-negative syphilis test.