WBR0712
Author | PageAuthor::William J Gibson |
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Exam Type | ExamType::USMLE Step 1 |
Main Category | MainCategory::Microbiology |
Sub Category | SubCategory::Dermatology, SubCategory::Infectious Disease |
Prompt | [[Prompt::A 19-year-old female presents to the Emergency Room for the sudden onset of fatigue, fever, headache, and vomiting over the past 6 hours. 30 minutes after presentation, she decompensates rapidly. Her temperature climbs to 104F, her blood pressure drops to 70/palpable and she loses consciousness. Her skin is covered in petechiae. CT scan reveals bilateral adrenal hemorrhage. Which of the following is the most likely causal organism?]] |
Answer A | AnswerA::Listeria monocytogenes |
Answer A Explanation | [[AnswerAExp::Listeria monocytogenes can cause Listeriosis and can be introduced to a host via oral exposure from spoiled food products like milk.]] |
Answer B | AnswerB::Neisseria meningitidis |
Answer B Explanation | [[AnswerBExp::Neisseria meningitidis causes Waterhouse-Friderichsen syndrome.]] |
Answer C | AnswerC::Salmonella typhi |
Answer C Explanation | [[AnswerCExp::Salmonella typhi causes typhoid fever.]] |
Answer D | AnswerD::Rickettsia prowazekii |
Answer D Explanation | [[AnswerDExp::Rickettsia prowazekii causes endemic typhus.]] |
Answer E | AnswerE::Staphylococcus aureus |
Answer E Explanation | [[AnswerEExp::Staphylococcus aureus causes staph scalded skin syndrome and toxic shock syndrome.]] |
Right Answer | RightAnswer::B |
Explanation | [[Explanation::The patient in this vignette has Waterhouse-Friderichsen syndrome (WFS), in which a bacterial infection leads to massive hemorrhage into one or (usually) both adrenal glands. WFS is most commonly caused by overwhelming blood-borne infection with Neisseria meningitidis, and is the most severe form of meningococcal septicemia. The onset of the illness is typically nonspecific with fever, rigors, vomiting, and headache. These symptoms are often followed by a macular rash that rapidly becomes petechial and purpuric with a dusky gray color. Hypotension develops and rapidly leads to septic shock. Extremities often become visibly cyanotic and patients can become comatose. Surprisingly, in this form of meningococcal disease, meningitis generally does not occur. Disseminated intravascular coagulation occurs along with the hallmark adrenal hemorrhage leading to adrenocortical insufficiency and often death. Educational Objective: Waterhouse-Friderichsen syndrome is characterized by bilateral adrenal hemorrhage and caused by Neisseria meningitidis. |
Approved | Approved::Yes |
Keyword | WBRKeyword::Waterhouse-Friderichsen syndrome, WBRKeyword::Microbiology, WBRKeyword::Infection, WBRKeyword::Bacteria |
Linked Question | Linked:: |
Order in Linked Questions | LinkedOrder:: |