A 26-year-old man presents to the emergency department with fevers, chills, malaise, and joint pain that started in his right knee 4 days ago and is now in his left wrist. On exam, his temperature is 39.0°C, and he looks ill. He has a small effusion of the right knee and you note a rash on his palms and the dorsum of his hands consisting of a couple of palpable purpura as well as a pustule with a small necrotic center, as seen in the image above. He has no other skin lesions and the rest of his physical exam is unremarkable. Which of the following is the most likely diagnosis?  

A 31-year-old woman, who has two healthy children, notes that she has had no menstrual periods for the past 6 months, but she is not pregnant and takes no medications. Within the past week, she has noted some milk production from her breasts. She has been bothered by headaches for the past 3 months. After nearly hitting a bus while changing lanes driving her vehicle, she is concerned with her vision. An optometrist finds her lateral vision to be reduced. On physical examination she is afebrile and normotensive. Which of the following laboratory test findings is most likely to be present in this woman?

A 6-year-old immigrant boy from Bangladesh presents with fever and rash. The fever started 3 days ago followed by a rash which started on the head and spread to the rest of the body. Examination reveals a well appearing child with a maculopapular rash and posterior cervical lymphadenopathy. Which of the following is the most likely causative organism for this disease?

A 10-year-old boy returns to the ED for the second time in a week complaining of a right-sided headache. Five days ago, he was also seen for a right-sided headache, thick nasal drainage, and fever. A diagnosis of acute sinusitis was made, and he was discharged on amoxicillin-clavulanate, nasal spray, and decongestants. Today, he returns for continued pain above his right eye, fever, vomiting, and confusion. Vital signs are T 39.4°C, BP 85/40 mm Hg, HR 130 bpm, and RR 32/min. His exam is notable for drowsiness, confusion, yellow nasal discharge from both nares, and tachycardia. Which of the following findings confirms the most likely diagnosis?

Which of the following is at the highest risk for suicide?

Which of the following patients mandates reporting to health authorities in all 50 states or to federal officials?

Which of the following features, in addition to progressive cognitive decline, is most consistent with a diagnosis of dementia with Lewy bodies?

Which of the following fish poisonings is associated with a peppery taste?

A 33-year-old man presents to the ED with a 2-day history of a cough with rust-colored sputum, fever, and chills. He has no past medical history and has had no recent illnesses or hospitalizations. In the ED, his vital signs are BP 120/76, HR 102, RR 22, oxygen saturation 97% on room air, and temperature 102.2°F. A chest X-ray shows a right lower lobe consolidation. The patient is diagnosed with pneumonia. What is the most likely pathogen?

An 8-year-old boy is brought to the ED by his parents after they discovered a tick attached to his right armpit. What is the best way to remove the tick?