A 34-year-old woman presents with fatigue, malaise, and swollen, tender joints. Physical examination is significant for a maculopapular eruption over sun-exposed areas, including the face. Examination of a peripheral blood smear reveals mild thrombocytopenia. Which of the following autoantibodies, if present, would be most specific for the diagnosis of the patient's disorder?
A 43-year-old executive presents to a physician with chronic, symmetric polyarthritis involving the knees. The man gives a history of having developed an extensive rash after a deer hunting trip in Connecticut several years earlier. He recalls that he felt 'sick' at the time, and developed knee pain that prevented him from climbing stairs for several months, but then partially resolved. Which of the following organisms is most likely etiologically related to the patient's arthritis?
An active intravenous drug abuser presents to the emergency department with fever of 5 days' duration, a cough occasionally productive of blood, and pleuritic chest pain. Petechiae are present in his mouth and conjunctivae, and splinter hemorrhages are visible under the fingernails. Which of the following test results would most likely confirm the identity of the causative agent?
A 20-year-old female presents with a two day history of dysuria and increased urinary frequency. She states that she was recently married and was not sexually active prior to the marriage. Physical exam reveals a temperature of 100.7 蚌 with normal vital signs. Gynecological exam reveals no evidence of discharge, vaginitis, or cervicitis. Urinalysis reveals 14 white blood cells per high-powered field with many gram-negative rods. The most appropriate therapy would be
One week following a visit to the woods along an Eastern seaboard beach, a 50-year-old woman develops fever, headache, chills, and fatigue. A blood smear demonstrates protozoa within erythrocytes. Which of the following is the most likely pathogen?
Which of the following organisms is the most common cause of community-acquired pneumonia?
A 37-year-old, intravenous drug-abusing male presents with fever and chills. Blood cultures are positive for Staphylococcus aureus. He develops central nervous system symptoms, and a cerebral abscess is suspected. Which part of the brain is most often affected by septic emboli in patients with infective endocarditis?
A 36-year-old mother of two children presents with a 4-day history of swollen, painful hands. Her wrists and metacarpophalangeal joints are boggy and inflamed bilaterally. Her 5-year-old son had been sent home from school approximately 3 weeks previously with red cheeks and a blotchy rash on his torso. What is the most likely diagnosis?
A 16-year-old girl presents with a painlessly enlarged lymph node in her right axilla. Peripheral blood counts are within normal limits. The lymph node is biopsied, and numerous granulomas filled with neutrophils and necrotic debris are observed. Which of the following organisms could produce this disease?
A newborn in the neonatal intensive care unit becomes tachypneic and irritable. Blood cultures grow a gram-positive coccus in chains that is presumed to be a streptococcus. Which of the following characteristics would help to differentiate Streptococcus agalactiae from Streptococcus pneumoniae?