Fever pathophysiology — MCQs

A 6-year-old boy is presented to a pediatric clinic by his mother with complaints of fever, malaise, and cough for the past 2 days. He frequently complains of a sore throat and has difficulty eating solid foods. The mother mentions that, initially, the boy’s fever was low-grade and intermittent but later became high grade and continuous. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. The past medical history is noncontributory. The boy takes a multivitamin every day. The mother reports that he does well in school and is helpful around the house. The boy’s vital signs include blood pressure 110/65 mm Hg, heart rate 110/min, respiratory rate 32/min, and temperature 38.3°C (101.0°F). On physical examination, the boy appears uncomfortable and has difficulty breathing. His heart is mildly tachycardic with a regular rhythm and his lungs are clear to auscultation bilaterally. Oropharyngeal examination shows that his palatine tonsils are covered with pus and that there is erythema of the surrounding mucosa. Which of the following mediators is responsible for this patient’s elevated temperature?

A 55-year-old woman with diabetes presents to the emergency department due to swelling of her left leg, fever, and chills for the past 2 days. The woman’s maximum recorded temperature at home was 38.3°C (101.0°F). Her left leg is red and swollen from her ankle to the calf, with an ill-defined edge. Her vital signs include: blood pressure 120/78 mm Hg, pulse rate 94/min, temperature 38.3°C (101.0°F), and respiratory rate 16/min. On physical examination, her left leg shows marked tenderness and warmth compared with her right leg. The left inguinal lymph node is enlarged to 3 x 3 cm. Which of the following chemical mediators is the most likely cause of the woman’s fever?

A 3-day-old female newborn is brought to the emergency department because of fever, poor feeding, and irritability for 6 hours. She was delivered at home at 39 weeks' gestation and delivery was uncomplicated. The mother had no prenatal care. Her temperature is 39.8°C (103.6°F), pulse is 172/min, respirations are 58/min, and blood pressure is 74/45 mm Hg. She appears lethargic. Physical examination shows expiratory grunting and nasal flaring. Serum studies show elevated levels of interleukin-6. Which of the following is the most likely effect of this laboratory finding?

A group of investigators is studying thermoregulatory adaptations of the human body. A subject is seated in a thermally insulated isolation chamber with an internal temperature of 48°C (118°F), a pressure of 1 atmosphere, and a relative humidity of 10%. Which of the following is the primary mechanism of heat loss in this subject?

A researcher is studying how arachidonic acid metabolites mediate the inflammatory response in rats. She has developed multiple enzyme inhibitors that specifically target individual proteins in the arachidonic acid pathway. She injects these inhibitors in rats who have been exposed to common bacterial pathogens and analyzes their downstream effects. In one of her experiments, she injects a leukotriene B4 inhibitor into a rat and observes an abnormal cell response. Which of the following interleukins would most closely restore the function of one of the missing products?

While playing in the woods with friends, a 14-year-old African-American male is bitten by an insect. Minutes later he notices swelling and redness at the site of the insect bite. Which substance has directly led to the wheal formation?

A 38-year-old man comes to the physician because of severe muscle pain and swelling of his eyelids for 3 days. He has also had fever and chills during this period. For the last 2 days, he has had severe pain in his mouth while chewing. He had an episode of diarrhea a month ago for which he did not seek medical care. He has no history of serious illness. His sister has dermatomyositis. He returned from a hunting trip to eastern Europe 45 days ago. His temperature is 38.1°C (100.6°F), pulse is 80/min, and blood pressure is 130/70 mm Hg. Examination shows periorbital edema and severe generalized muscle tenderness. There are splinter hemorrhages on both hands. Laboratory studies show: Hemoglobin 14.2 g/dL Leukocyte count 12,500/mm3 Segmented neutrophils 60% Eosinophils 18% Lymphocytes 20% Monocytes 2% Serum Glucose 117 mg/dL Creatinine 1.1 mg/dL Alkaline phosphatase 72 U/L Creatine kinase 765 U/L Urinalysis is within normal limits. Which of the following is most likely to have prevented this patient's condition?

A parent presents to her pediatrician requesting information about immunizations for her newborn. The pediatrician explains about basic principles of immunization, types of vaccines, possible adverse effects, and the immunization schedule. Regarding how immunizations work, the pediatrician explains that there are mainly 2 types of vaccines. The first type of vaccine provides stronger and more lasting immunity as it induces both cellular and humoral immune responses. The second type of vaccine produces mainly a humoral response only, and its overall efficacy is less as compared to the first type. Which of the following vaccines belongs to the first type of vaccine that the pediatrician is talking about?

An investigator is studying the clearance of respiratory particles in healthy non-smokers. An aerosol containing radio-labeled particles that are small enough to reach the alveoli is administered to the subjects via a non-rebreather mask. A gamma scanner is then used to evaluate the rate of particle clearance from the lungs. The primary mechanism of particle clearance most likely involves which of the following cell types?

A 42-year-old man undergoes therapeutic hypothermia (target temperature 33°C/91.4°F) following cardiac arrest with return of spontaneous circulation. During the cooling phase, he develops shivering, which increases oxygen consumption and interferes with target temperature achievement. He is already on sedation and neuromuscular blockade is being considered. Evaluate the most appropriate management strategy considering both efficacy and safety.