WBR0703

Author	[[PageAuthor::Mohamed Moubarak, M.D. [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Infectious Disease
Prompt	[[Prompt::19 year old boy present to the ER with generalized rash, he had fever and sore throat one week ago and got antibiotic prescription from his primary care physician 4 days ago. His past medical history is insignificant. He doesn’t smoke or consume recreational drugs or alcohol. He is sexually active with one partner and uses condoms regularly. Vital signs are normal except for temperature of 37.8 C(100 F). His physical examination reveals generalized maculopapular rash and posterior cervical lymphadenopathy. What is the most likely mechanism of rash development in that patient?]]
Answer A	AnswerA::Familial
Answer A Explanation	[[AnswerAExp::Incorrect Rash to ampicillin doesn’t represent familial predisposition]]
Answer B	AnswerB::Viral exanthema
Answer B Explanation	[[AnswerBExp::Incorrect Viral exanthema usually observed during active viral infections]]
Answer C	AnswerC::Immediate hypersensitivity
Answer C Explanation	[[AnswerCExp::Incorrect The rash doesn’t represent immediate hypersensitivity to ampicilline]]
Answer D	AnswerD::Delayed hypersensitivity
Answer D Explanation	[[AnswerDExp::Incorrect The rash doesn’t represent delayed hypersensitivity to ampicilline]]
Answer E	AnswerE::Immune complexes
Answer E Explanation	[[AnswerEExp::Correct Circulating IgG and IgM antibodies targeting penicillin derivatives is the cause of the well known ampicilline-associated maculopapular rash phenomenon in patients with infectious mononucleosis]]
Right Answer	RightAnswer::E
Explanation	[[Explanation::Ampicilline-associated maculopapular rash in patients with infectious mononucleosis is a well know phenomenon. It is caused by the circulating IgG and IgM targeting penicillin derivatives causing this immune vasculitic rash Educational Objective: References: ]]
Approved	Approved::No
Keyword
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::