Infectious Disease — MCQs

A 7-year-old boy is brought to the emergency department because of high-grade fever and lethargy for 4 days. He has had a severe headache for 3 days and 2 episodes of non-bilious vomiting. He has sickle cell disease. His only medication is hydroxyurea. His mother has refused vaccinations and antibiotics in the past because of their possible side effects. He appears ill. His temperature is 40.1°C (104.2°F), pulse is 131/min, and blood pressure is 92/50 mm Hg. Examination shows nuchal rigidity. Kernig and Brudzinski signs are present. A lumbar puncture is performed. Analysis of the cerebrospinal fluid (CSF) shows a decreased glucose concentration, increased protein concentration, and numerous segmented neutrophils. A Gram stain of the CSF shows gram-negative coccobacilli. This patient is at greatest risk for which of the following complications?

A 5-year-old girl is brought to her pediatrician by her mother. The mother is concerned about a fine, red rash on her daughter’s limbs and easy bruising. The rash started about 1 week ago and has progressed. Past medical history is significant for a minor cold two weeks ago. The girl was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines and is meeting all developmental milestones. Today, she has a heart rate of 90/min, respiratory rate of 22/min, blood pressure of 110/65 mm Hg, and temperature of 37.0°C (98.6°F). On physical exam, the girl has a petechial rash on her arms and legs. Additionally, there are several bruises on her shins and thighs. A CBC shows thrombocytopenia (20,000/mm3). Other parameters of the CBC are within expected range for her age. Prothrombin time (PT), partial thromboplastin time (PTT), and metabolic panels are all within reference range. What is the most likely blood disorder?

A 7-year-old boy is brought to his pediatrician's office by his mother with a new onset rash. His mother says that the rash appeared suddenly yesterday. He is otherwise well. His medical history is unremarkable except for a recent upper respiratory infection that resolved without intervention two weeks ago. His temperature is 98.2°F (36.8°C), blood pressure is 110/74 mmHg, pulse is 84/min, and respirations are 18/min. Physical exam shows a well appearing child with a diffuse petechial rash. Complete blood count shows the following: Hemoglobin: 12.6 g/dL Hematocrit: 37% Leukocyte count: 5,100/mm^3 Platelet count: 65,000/mm^3 Which of the following is the best choice in management?

A 10-year-old boy is brought to the emergency department by his parents because of a dull persistent headache beginning that morning. He has nausea and has vomited twice. During the past four days, the patient has had left-sided ear pain and fever, but his parents did not seek medical attention. He is from Thailand and is visiting his relatives in the United States for the summer. There is no personal or family history of serious illness. He is at the 45th percentile for height and 40th percentile for weight. He appears irritable. His temperature is 38.5°C (101.3°F), pulse is 110/min, and blood pressure is 98/58 mm Hg. The pupils are equal and reactive to light. Lateral gaze of the left eye is limited. The left tympanic membrane is erythematous with purulent discharge. There is no nuchal rigidity. Which of the following is the most appropriate next step in management?

A 10-year-old girl is admitted to the medical floor for a respiratory infection. The patient lives in a foster home and has been admitted many times. Since birth, the patient has had repeated episodes of pain/pressure over her frontal sinuses and a chronic cough that produces mucus. She was recently treated with amoxicillin for an infection. The patient is in the 25th percentile for height and weight which has been constant since birth. Her guardians state that the patient has normal bowel movements and has been gaining weight appropriately. The patient has a history of tricuspid stenosis. She also recently had magnetic resonance imaging (MRI) of her chest which demonstrated dilation of her airways. Her temperature is 99.5°F (37.5°C), blood pressure is 90/58 mmHg, pulse is 120/min, respirations are 18/min, and oxygen saturation is 94% on room air. Physical exam is notable for bruises along the patient's shins which the guardians state are from playing soccer. The rest of the exam is deferred because the patient starts crying. Which of the following findings is associated with this patient's most likely underlying diagnosis?

A 6-year-old girl is brought to the clinic for evaluation of malaise and low-grade fever over the past 3 days. In the last 24 hours, she developed sores and pain in her mouth. She also had vesicles on her hands and feet. Her past medical history was benign and the immunization history was up-to-date. The oral temperature was 38.1°C (100.6°F). The physical examination revealed several erythematous macules in the oropharynx and small oval vesicles with an erythematous base on the palms. What is the next best step in the management of this patient?

An 8-year-old girl is brought to the emergency department by her parents with severe difficulty in breathing for an hour. She is struggling to breathe. She was playing outside with her friends, when she suddenly fell to the ground, out of breath. She was diagnosed with asthma one year before and has since been on treatment for it. At present, she is sitting leaning forward with severe retractions of the intercostal muscles. She is unable to lie down. Her parents mentioned that she has already taken several puffs of her inhaler since this episode began but without response. On physical examination, her lungs are hyperresonant to percussion and there is decreased air entry in both of her lungs. Her vital signs show: blood pressure 110/60 mm Hg, pulse 110/min, respirations 22/min, and a peak expiratory flow rate (PEFR) of 50%. She is having difficulty in communicating with the physician. Her blood is sent for evaluation and a chest X-ray is ordered. Her arterial blood gas reports are as follows: PaO2 50 mm Hg pH 7.38 PaCO2 47 mm Hg HCO3 27 mEq/L Which of the following is the most appropriate next step in management?

A 3-year-old boy is brought to the emergency department by his mother because of a cough and mild shortness of breath for the past 12 hours. He has not had fever. He has been to the emergency department 4 times during the past 6 months for treatment of asthma exacerbations. His 9-month-old sister was treated for bronchiolitis a week ago. His father has allergic rhinitis. Current medications include an albuterol inhaler and a formoterol-fluticasone inhaler. He appears in mild distress. His temperature is 37.5°C (99.5°F), pulse is 101/min, respirations are 28/min, and blood pressure is 86/60 mm Hg. Examination shows mild intercostal and subcostal retractions. Pulmonary examination shows decreased breath sounds and mild expiratory wheezing throughout the right lung field. Cardiac examination shows no abnormalities. An x-ray of the chest shows hyperlucency of the right lung field with decreased pulmonary markings. Which of the following is the next best step in management?

A 4-year-old child is brought to a pediatric clinic with complaints of a foul-smelling, recurrent, persistent vaginal discharge that started a few days ago. The child shows increased irritability with a slightly elevated temperature. The mother says that the child plays in the house and has no contact with other children. What is the most common cause of this patient’s symptom?

A 5-year-old boy is brought to the physician because of a nonpruritic rash on his face that began 5 days ago. It started as a bug bite on his chin that then developed into small pustules with surrounding redness. He has not yet received any routine childhood vaccinations. Physical examination shows small, clustered lesions with gold crusts along the lower lip and chin and submandibular lymphadenopathy. At a follow-up examination 2 weeks later, his serum anti-deoxyribonuclease B antibody titer is elevated. This patient is at greatest risk for which of the following complications?