WBR0058

Author	PageAuthor::William J Gibson (Reviewed by Yazan Daaboul)
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology, MainCategory::Pharmacology
Sub Category	SubCategory::Dermatology, SubCategory::General Principles, SubCategory::Infectious Disease
Prompt	[[Prompt::A 27-year-old woman presents to her primary care physician complaining of fever, flu-like symptoms, and a rash. She recently returned from a camping trip in Boston. Physical examination is remarkable for erythema chronicum migrans. What is the optimal treatment for this patient?]]
Answer A	AnswerA::Erythromycin
Answer A Explanation	AnswerAExp::Erythromycin is a macrolide used to treat atypical pneumonias
Answer B	AnswerB::Doxycycline
Answer B Explanation	AnswerBExp::Doxyclince is a tetracycline used to treat Lyme disease.
Answer C	AnswerC::Penicillin
Answer C Explanation	AnswerCExp::Penicillin is a beta-lactam antibiotic used to treat some gram-positive organisms, some gram-negative organisms, and syphilis.
Answer D	AnswerD::Trimethoprim-Sulfamethoxazole (TMP-SMX)
Answer D Explanation	AnswerDExp::Trimethoprim-Sulfamethoxazole (TMP-SMX) inhibits dihyrofolate reductase and may used to treat UTIs, and ''Pneumocystis jirovecii'' infection in HIV-positive patients.
Answer E	AnswerE::Ciprofloxacin
Answer E Explanation	AnswerEExp::Ciprofloxacin is a fluoroquinolone which inhibits DNA gyrase and is used to treat gram-negative rods and ''Pseudomonas aeruginosa''.
Right Answer	RightAnswer::B
Explanation	[[Explanation::The patient in this vignette has the early (primary) stage of Lyme disease, caused by the spirochete Borrelia burgdorferi. Borrelia burgdorferi is a zoonotic bacteria that is carried by the Ixodes (deer) tick. In its early stages, Lyme disease causes flu-like symptoms and a characteristic “bullseye” rash called erythema chronicum migrans present in 80% of patients. The incubation period of Lyme disease can vary greatly, but is typically 1 to 2 weeks. If untreated, Lyme disease can cause facial palsy and AV nodal block (secondary Lyme disease) progressing to chronic monoarthritis or migratory polyarthritis (tertiary Lyme disease). It is endemic to Northeastern USA. Treatment is generally by doxycyline. Educational Objective: Primary (early) lyme disease is optimally treated with tetracycline antibiotics, such as doxycycline. References: First Aid 2014 page 141]]
Approved	Approved::Yes
Keyword	WBRKeyword::Microbiology, WBRKeyword::Zoonotic, WBRKeyword::Animal, WBRKeyword::Tick, WBRKeyword::Lyme disease, WBRKeyword::Lyme, WBRKeyword::Bacteria, WBRKeyword::Rash, WBRKeyword::Dermatology, WBRKeyword::Pharmacology, WBRKeyword::Drugs, WBRKeyword::Antibiotics, WBRKeyword::Linked
Linked Question	Linked::
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