WBR0204

Author	PageAuthor::William J Gibson (Reviewed by Serge Korjian)
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 of 192 cells/mm3 and viral load of 52,432 copies/mL. Physical examination reveals a white patch on the right side of the tongue that cannot be scraped off. What is the most likely organism responsible for this finding?]]
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::Human Herpes Virus 8 (HHV-8)
Answer B Explanation	AnswerBExp::HHV-8 is the virus responsible for Kaposi's sarcoma in patients with AIDS.
Answer C	AnswerC::Ebstein-Barr virus (EBV)
Answer C Explanation	AnswerCExp::Hairy leukoplakia is caused by Epstein-Barr virus (EBV) and is most commonly seen in HIV-infected patients.
Answer D	AnswerD::''Cryptococcus neoformans''
Answer D Explanation	[[AnswerDExp::Cryptococcus neoformans causes meningitis in AIDS patients predominantly those with a CD4 below 100 cells/mm3.]]
Answer E	AnswerE::Cytomegalovirus (CMV)
Answer E Explanation	[[AnswerEExp::CMV causes retinitis in HIV infected patients, typically when CD4 is below 50 cells/mm3.]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::The patient in this scenario 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 leaving an area of inflammation, whereas leukoplakia cannot. Hairy leukoplakia is caused by Epstein-Barr virus (EBV) and is most commonly seen in HIV-infected patients. As a benign lesion, it does not require treatment but it typically responds to acyclovir therapy. The presence of hairy leukoplakia may indicate a high degree of immunocompromise. Hairy leukoplakia should also be distinguished from idiopathic leukoplakia, a premalignant lesion of oral squamous cell carcinoma, seen in smokers and in patients that chew tobacco. Both these lesion cannot be scraped off. Educational Objective: Hairy leukoplakia is caused by EBV and is seen in patients with HIV/AIDS. 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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