WBR0204

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Author PageAuthor::William J Gibson
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Microbiology, MainCategory::Pathophysiology
Sub Category SubCategory::Head and Neck, SubCategory::Infectious Disease
Prompt [[Prompt::A 45-year-old HIV-positive man presents to your office with complaints of increasing fatigue, difficulty swallowing, and a 6.8 kg (15 lb) weight loss in the past 2 months. The patient is found to have a CD4+ count is 192 and viral load is 52,432. Physical exam reveals a white patch on the right side of the tongue which cannot be scraped off. What is the most likely causal organism?]]
Answer A AnswerA::Candida albicans
Answer A Explanation AnswerAExp::Candida Albicans is responsible for thrush, which is distinct from hairy leukoplakia. Thrush can be mechanically disturbed by scraping with tongue depressor whereas hairy leukoplakia cannot.
Answer B AnswerB::HHV-8
Answer B Explanation AnswerBExp::HHV-8 is thought to cause Kaposi Sarcoma in AIDS patients
Answer C AnswerC::EBV
Answer C Explanation AnswerCExp::See explanation
Answer D AnswerD::Cryptococcus
Answer D Explanation [[AnswerDExp::Cryptococcus causes meningitis in HIV infected patients with low CD4 (<100).]]
Answer E AnswerE::CMV
Answer E Explanation [[AnswerEExp::CMV causes retinitis in HIV infected patients, typically when CD4 < 50.]]
Right Answer RightAnswer::C
Explanation [[Explanation::The patient in this vignette is suffering from hairy leukoplakia, a white patch on the side of the tongue with a corrugated or hairy appearance. Hairy leukoplakia can be distinguished from oral candidiasis by the fact that candidiasis causes lesions which can be sloughed off by scraping whereas leukoplakia cannot. Hairy leukoplakia is caused by Epstein-Barr virus in HIV infected patients. As a benign lesion, it does not require treatment but typically responds to acyclovir. The presence of hairy leukoplakia may indicate a high degree of severity of the patients immunocompromisation.

Educational Objective: Hairy Leukoplakia in HIV patients is caused by EBV.
References: First Aid 2014 page 169]]

Approved Approved::Yes
Keyword WBRKeyword::HIV, WBRKeyword::EBV, WBRKeyword::Hairy leukoplakia, WBRKeyword::Immunodeficiency, WBRKeyword::Immunocompromised, WBRKeyword::Opportunistic infection
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