An 8-year-old boy is brought to his physician by his mother, who is worried by the child's frequent episodes of daydreaming, which have apparently resulted in a decline in school performance. The child's psychomotor development appears normal. EEG recording reveals bilateral and symmetric 3-Hz spike-and-wave discharges, which begin and end abruptly on a normal background. Which of the following is the most likely diagnosis?
A pregnant woman has premature rupture of membranes. Her baby is born 3 days later, at 37 weeks' gestation. The 5-minute APGAR score is 4. Lung sounds are reduced, and the infant appears to be in respiratory distress. Peripheral blood smear with differential counts demonstrates a neutrophil count of 30,000/mL, with toxic granules evident in many neutrophils. Gram stain of buffy coat demonstrates small gram-positive cocci in chains. Which of the following is the most likely causative organism?
A 6-year-old boy has multiple, honey-colored, crusted lesions on his face, periungual areas, and forearms. The first lesion appeared 2 weeks ago on his philtrum. Since then the lesions have spread to his hands and arms. Each began as a small pustule on an erythematous base and eventually ruptured to form the crusted lesions now present. His temperature is 38.1 C (100.6 F), pulse is 100/min, and respirations are 14/min. The remainder of the physical examination is unremarkable. Which of the following is the most appropriate treatment?
A 15-year-old girl has a round, 1-cm cystic mass in the midline of her neck, at the level of the hyoid bone. The mass is deep to the skin and moves slightly when the patient swallows. When the mass is palpated at the same time that the tongue is pulled, there seems to be a connection between the two. The mass has been present for at least 10 years, but only recently bothered the patient because it became infected. Which of the following is the most likely diagnosis?
A 2-year-old boy who emigrated from Eastern Europe 1 year ago is brought to the physician because of fever, cough, and night sweats for 3 weeks. The child's grandmother, who lives with him, has similar symptoms. The child's temperature is 39.2 C (102.6 F), blood pressure is 110/65 mm Hg, pulse is 90/min, and respirations are 28/min. A Mantoux test is reactive, and a chest x-ray film shows a right middle lobe infiltrate and hilar lymphadenopathy. Which of the following is the most appropriate next step in diagnosis?
A mother brings her 6-year-old daughter for evaluation because she has never been able to toilet train her. The child states that she perceives the sensation of having to void, and empties her bladder normally at normal intervals, but is nonetheless wet with urine all the time. Which of the following is the most likely diagnosis?
A neonate is noted to have an abnormally shaped face with a very small jaw. Several hours after birth, the baby develops convulsions and tetany. Serum chemistries show the following:
- Sodium 140 mEq/L
- Potassium 4 mEq/L
- Chloride 100 mEq/L
- Bicarbonate 24 mEq/L
- Magnesium 2 mEq/L
- Calcium 5 mg/dL
- Glucose 100 mg/dL
This child's disorder is associated with aplasia or hypoplasia of which of the following organs?
A 10-year-old girl is brought to the physician because of throat pain, anorexia, and fever for 2 days. Her temperature is 38.9 C (102.0 F). The patient's history is negative for allergic diseases. She has had two episodes of pharyngotonsillitis over the past several years. Examination reveals a purulent exudate in the posterior oropharynx and enlarged tonsils. There is bilateral tender enlargement of anterior cervical lymph nodes. Cardiac and chest auscultation is normal. A rapid strep test is positive. Which of the following is the most appropriate next step in management?
A 12-year-old girl is seen by a pediatrician for a mild case of pneumonia. She is treated with an intramuscular injection of penicillin. About 15 minutes later, she develops extreme itchiness, accompanied by the development of wheals scattered over her chest and extremities. She also begins to wheeze and complain of difficulty breathing. The color of her lips and face remains rosy. Which of the following is the most appropriate first step in management?
A 11-month-old boy is brought to the emergency department by his parents. The child has a fracture of the right femur. The father reports this was sustained as a result of falling out of the crib. The child is also noted to have bruises on his shoulders and back. The rest of his examination is unremarkable. Which of the following is the most appropriate next step in diagnosis?
A 4-week-old male infant has been spitting up his formula feedings for the past few days. He does not vomit bilious material or blood. The spitting up is gradually becoming more frequent, and forceful vomiting ensues. The vomitus seems to shoot straight out and nearly hit the wall. On examination, the baby seems hungry and is chewing his fist. His mucous membranes appear dry. A small, round mass, about the size of an adult thumbnail, is palpated in the upper abdomen. Laboratory data reveal Na⁺ of 133 mEq/L, K⁺ of 3.5 mEq/L, Cl⁻ of 93 mEq/L, and HCO₃⁻ of 29 mEq/L. Which of the following is the most appropriate next step in management?
An infant has had repeated pneumonias and middle ear infections that began at about 5 months of age. At 1 year of age, serum electrophoresis demonstrated hypogam-maglobulinemia. T cell function was normal. By 2 years of age, the child's infection rate has decreased, and repeat serum electrophoresis is normal. Which of the following immunoglobulins was likely decreased in this child during the period of increased susceptibility to infection?
