USLME pediatrie

A 2-week-old male infant is brought to the office by his 28-year-old primiparous mother for the evaluation of jaundice that was noted two days ago. The infant's stool has a lighter color. He is exclusively breastfed. The pregnancy was uncomplicated, and prenatal screening tests for TORCH organisms were all negative. The infant was delivered vaginally with no complications. His temperature is 37.2 C (99F), pulse is 140/min, respirations are 50/min, and capillary refill is < 2 sec. Examination reveals jaundiced skin and mucous membranes. Abdominal palpation reveals hepatomegaly. The initial investigations show the following: Hb 18.0 g/dl, Hct 52%, Bilirubin, Total 5 mg/dl, Bilirubin, Direct 4 mg/dl, Blood type 0 + (The mother's blood type is B-), Coombs' test Negative. What is the most likely diagnosis?

The infant in the following picture presents with hepatosplenomegaly, anemia, persistent rhinitis, and a maculopapular rash. Which of the following is the most likely diagnosis for this child?

A premature infant develops respiratory distress several hours after birth. The infant is placed in an incubator with supplemental oxygen. The physician instructs the nurse to cover the infant's eyes to minimize the chance of damage by the high oxygen tension. Which of the following is characteristic of eye damage produced by exposure to high oxygen tensions in premature infants with respiratory distress?

A 7-year-old boy is brought to the clinic by his mother, who states that he has been complaining of abdominal pain for 2-3 days. He has been afebrile, with no vomiting or diarrhea. His mother states she brought him to the office today because she noticed a rash on his legs that is getting worse, and he is now complaining of knee pain. On examination, there are palpable purpuric lesions on both legs and buttocks. He has pain around his ankle and knee joints with minimal swelling, and no warmth or erythema. Which of the following is the most likely diagnosis?

A 7-year-old boy who has had pain in his right leg for 4 months is being evaluated. The pain is worse at night and is unrelenting, but it can usually be relieved with ibuprofen. On physical examination, there is localized tenderness over the anterior aspect of the right thigh. There is also mild atrophy of the affected limb. A radiograph of the femur reveals a radiolucent nidus with surrounding reactive sclerotic bone. Which of the following is the most likely diagnosis?

A 2-year-old boy is brought to the emergency department due to a cough and a "whistling" sound with breathing. Two days ago, he developed rhinorrhea, fever, a hoarse cry and a progressively worsening, harsh, "barky" cough. His immunizations are up-to-date. His 6-year-old brother also has cold symptoms. His temperature is 37.5C (99.5F), pulse is 140/min, and respirations are 36/min. On examination, he is alert, in mild respiratory distress, has a dry barking cough, hoarse cry, and some clear mucoid rhinorrhea. His pharynx is slightly injected, but without enlargement or asymmetry. The lungs are clear on auscultation. Lateral neck x-rays reveal a mildly narrowed subglottic region. What is the most likely diagnosis?

A 2-year-old child is brought to the physician for a routine visit. He is growing and developing appropriately. He eats a variety of foods including meat, vegetables, and fruits, and drinks 3-4 glasses of whole milk each day. He is starting to put words together into short sentences. His mother has no concerns. Physical examination is unremarkable. Routine laboratory studies show the following: Hemoglobin 9.5 g/dl, RDW 14%, MCV 65 fl, Reticulocyte count 3.0%, Platelet count 212,000/mm3, Leukocyte count 6,500/mm3, TIBC 300 mcg/dl (240-450 mcg/dl), Ferritin 100 ng/ml (7 -140 ng/ml). What is the most likely cause for this child's anemia?

A previously healthy 5-year-old girl is brought to the physician for evaluation of night awakenings. She has woken up screaming in each of the past three nights about one hour after going to sleep. When her parents go to her room, she is crying, sweating, and looks frightened. She does not respond to her parents and does not seem fully awake. When her parents hold her, she calms down and goes back to sleep. The next morning, she does not recall the incident. She started kindergarten this week and has just begun going all day without taking a nap. On examination, she is afebrile and her vital signs are within normal limits. A complete physical examination is unremarkable. What is the most likely diagnosis?

A 17-year-old boy comes to medical attention because of recurrent sinusitis and pneumonia, and persistent watery diarrhea due to Giardia lamblia. His parents and a sister are in excellent health. Physical examination reveals enlarged lymph nodes in cervical, axillary and inguinal regions. A lymph node biopsy shows hyperplastic follicles with an absence of plasma cells. Laboratory investigations show: Hematocrit44%, Leukocyte count9, 800/mm3, Neutrophils55%, Lymphocytes30%, Monocytes5%, CD4 T-cell count1000 cells/mm3, Proteins, serum6.2 g/dL, Albumin5.0 g/dL, Globulin1.2 g/dL. Additional studies demonstrate severely depressed levels of serum IgG, with slightly below-normal levels of IgM and IgA. Which of the following is the most likely diagnosis?

An 8-year-old boy presents with a 2-day history of rash. The rash started on the head and spread downward to his trunk and extremities. He also complains of a fever, cough, and a runny nose for the past 5 days. On physical examination, his temperature is 38.2 C (100.7 F), blood pressure is 88/56 mm Hg, pulse is 76/min, and respirations are 16/min. There is a small, irregular red spot with a central gray color on his buccal mucosa. The rash on his body is erythematous and maculopapular in quality. Which of the following is the most likely diagnosis?

A 3-year-old child presents in clinic with marked erythema of the cheeks, with no prior symptoms. The rash soon involves the arms and has a reticular erythematous maculopapular appearance. The patient has been previously healthy and is not on any medications. He has not been exposed to any other ill individual. Which of the following is the most likely diagnosis?

The mother of a 6-month-old infant is concerned that her baby may be teething. You explain to her that the first teeth to erupt in most children are which of the following?

A 6-month-old previously health child is brought to the doctor's office because of sudden onset of lethargy, constipation, generalized weakness and poor feeding. He has been meeting all development milestones and his immunization schedule is up to date. On further questioning, his parents mention that his diet was recently advanced to a homemade formula of evaporated milk and honey. On physical examination, he has stable vital signs, clear lungs, normal skin turgor and full fontanelles. Which of the following is the most likely explanation for the patient's presentation?

A 15-year-old girl presents to the emergency department with the sudden onset of watery diarrhea tinged with blood. The girl was previously healthy. Her only medications are topical benzoyl peroxide and oral clindamycin for acne vulgaris. Physical examination reveals a slightly distended abdomen that is diffusely tender. Her temperature is 38.1 C (100.5 F). She has not been exposed to any uncooked meat and has not eaten any unusual foods. Which of the following is the most likely diagnosis?

A 22-year-old woman has just delivered a male infant at 41 weeks of gestation. Her medical history is normal and her pregnancy was uncomplicated. She is an assistant in a veterinary clinic. Examination of the infant reveals jaundice, hepatosplenomegaly, and generalized lymphadenopathy. During the examination, he suddenly begins to have tonic-clonic seizures. The CT scan reveals active inflammatory lesions, hydrocephalus and intracranial calcifications. What is the most likely diagnosis of this patient?

A 5-year-old girl is brought to the physician's office for a follow-up visit after recovering from an episode of acute bacterial meningitis. Five weeks ago, she developed pneumococcal meningitis, and was admitted to the hospital, where she underwent lumbar puncture, CT scan of the head, and ceftriaxone therapy. She was discharged in a stable condition. According to the mother, the child has not been performing well in school since her illness. She also noticed that the child has forgotten how to copy figures such as triangles and squares, and is unable to identify colours accurately. What is the most likely cause for the regression of milestones in this patient?

A 5-year-old boy is brought to the physician because of a malodorous discharge coming from his right nostril. His parents report that the child developed frequent sneezing and mucus discharge for one week. They thought it was a common cold. The child is afebrile and in apparent good health. There is no history of allergic diseases or recurrent infections. Examination reveals obstruction of the right nasal fossa with associated purulent discharge from the right nostril. Which of the following is the most likely diagnosis?

A 4-year-old girl is brought to your office by her mother for recent onset of fever and rash. For the past 4 days, she has had headaches, fever, and sore throat. She was apparently normal 4 days ago, and upon presentation of the symptoms, her mother thought that she was having a simple viral fever which would go away with time; however, she then developed a pale pink maculo-papular rash, first on the face and neck, and then it rapidly spread onto the trunk and limbs. On examination, the child is afebrile and doesn't appear ill, but there are few palpable suboccipital and posterior auricular lymph nodes. What is the most likely cause of this patient's condition?

For the past year, a 12-year-old boy has had recurrent episodes of swelling of his hands and feet, which has been getting worse recently. These episodes occur following exercise and emotional stress, last for 2 to 3 days, and resolve spontaneously. The last episode was accompanied by abdominal pain, vomiting, and diarrhea. The results of routine laboratory workup are normal. An older sister and a maternal uncle have had similar episodes, but they were not given a diagnosis. He presents today with another episode as shown in the photographs on the next page. Which of the following is the most likely diagnosis?

During a regular checkup of an 8-year-old child, you note a loud first heart sound with a fixed and widely split second heart sound at the upper left sternal border that does not change with respirations. The patient is otherwise active and healthy. Which of the following heart lesions most likely explains these findings?

A 2-year-old child with minimal cyanosis has an S3 and S4 (a quadruple rhythm), a systolic murmur in the pulmonic area, and a middiastolic murmur along the lower left sternal border. An ECG shows right atrial hypertrophy and a ventricular block pattern in the right chest leads. Which of the following is the most likely diagnosis?

An 18-year-old male undergoes elective hernia repair. During the operation, he suffers considerable blood loss, and receives a blood transfusion. He then experiences an anaphylactic transfusion reaction. He is resuscitated and further hospital course is uncomplicated. His past medical history is significant for recurrent sinopulmonary infections and intermittent episodes of diarrhea since childhood. Which of the following is the most likely cause of his symptoms?

A 2-hour-old male neonate has developed worsening cyanosis over the past few minutes. The infant was vaginally delivered (assisted with forceps) at full term and weighed 4.1 kg (9 lb). The Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. Oxygen is administered by mask but does not relieve the cyanosis. Further examination reveals tachypnea, subcostal retractions, a normal first heart sound, a single and loud second heart sound (S2), and no murmur. Which of the following is the most likely cause of the infant's cyanosis?

A 5-year-old girl presents to the emergency department with acute onset of muscle weakness. The mother carried the girl to the examination room and states that the muscle weakness started in her daughter's legs yesterday. The weakness became worse today and progressed to the trunk and both arms. She was also complaining difficulty of breathing earlier today. She has been otherwise healthy but had a common cold about 10 days ago. On examination, her respirations are 26/min and shallow. She has profound muscle weakness in her lower extremities, and moderate weakness in her upper extremities. Her deep tendon reflexes are absent. A lumbar puncture is performed, which shows increased protein concentration but no pleocytosis. Which of the following is the most likely diagnosis?

A 4-year-old previously healthy but unimmunized boy presents with sudden onset of high fever, inspiratory stridor, and refusal to drink. Of the following causes of inspiratory stridor, which best fits this clinical scenario?

A week-old infant presents blood in his stools. He was born at home, with the father assisting in the delivery; no physician or midwife was present. He has been breast-fed and has been nursing well. On examination, you also note some blood in his nose. He is not jaundiced; a rectal examination and guaic test of the stool confirms that blood is present. His examination is otherwise normal. He is on no medications. Which of the following is the most likely diagnosis?

A 12-year-old American boy comes to you with the complaints of abdominal pain and dark urine. On examination he has normal vitals, icteric sclerae, and abdominal tenderness with a mass palpable in right upper quadrant. His laboratory report shows bilirubin: 6.5 mg/di, negative viral serologies and mild elevations of amylase and lipase. Ultrasonography shows a cystic extra hepatic mass and a gall bladder separated from the mass. What is the most likely diagnosis in this patient?

A 10-year-old boy has been having “bellyaches” for about 2 years. They occur at night as well as during the day. Occasionally, he vomits after the onset of pain. Occult blood has been found in his stool. His father also gets frequent, nonspecific stomachaches. Which of the following is the most likely diagnosis?

During a well-child visit, the grandmother of an 18-month-old patient is concerned because the child’s feet turn inward. She first noticed this when her grandson began to walk. It does not seem to bother the child. On examining his gait, his knees point forward and his feet turn inward. Which of the following is the most likely cause of this condition?

Two weeks after a viral syndrome, a 9-year-old boy presents to your clinic with a complaint of several days of weakness of his mouth. In addition to the drooping of the left side of his mouth, you note that he is unable to completely shut his left eye. His smile is asymmetric, but his examination is otherwise normal. Which of the following is the most likely diagnosis?

A 4-year-old girl is noticed by her grandmother to have a limp and a some-what swollen left knee. The parents report that the patient occasionally com- plains of pain in that knee. An ophthalmologic examination reveals findings as depicted in the photograph. Which of the following conditions is most likely to be associated with these findings?

A 1-month old boy is brought to the emergency department by his mother, who states that he has been having what she describes as "projectile vomiting" for the past several days. She states that he vomits every time she feeds him, and the situation seems to be getting worse, although he does not seem to be in pain. She describes the vomitus as non-bilious, and he has had normal stools with no blood in them. On examination, the infant appears to be mildly dehydrated, his abdomen is soft, and there is a palpable, olive-sized, firm moveable mass in the right upper quadrant. Which of the following is the most likely diagnosis?

A pediatrician examines a 2-month-old infant who had been born at term. The pediatrician hears a continuous murmur at the upper left sternal border. The peripheral pulses in all extremities are full and show widened pulse pressure. Which of the following is the most likely diagnosis?

A 3-week-old infant is being evaluated for hematochezia. His mother states that the infant passed stools j that contain both blood and mucus. There were no complications during her pregnancy, and the infant has been otherwise healthy. On physical examination, his temperature is 37.1 C (98.9 F), pulse is 110/min, and respirations are 18/min. He appears well, and his fontanelle is flat and level. Abdominal examination reveals normal active bowel sounds; his abdomen is nontender to palpation and there is no mass. His diaper contains stool that has bright red blood on it with mucus. Which of the following is the most likely explanation of his hematochezia?

A 7-year-old boy is brought to the physician because of a persistent mucopurulent nasal discharge for 2 weeks following a common cold. The mother also reports that the child has had frequent cough during the day and occasional temperatures up to 38.0 C (100.5 F). The child does not appear critically ill, but he complains of mild pain in the maxillary region and nasal obstruction. Rhinoscopic examination reveals a rivulet of purulent fluid coming from the inferior meatus. The rest of the physical examination is normal. Which of the following is the most likely diagnosis?

A 9-year-old boy presents with a several-day history of progressive arm and leg weakness. He has been well except for an upper respiratory infection 2 weeks ago. The patient is alert and oriented. On repeated examination, the heart rate varies between 60 and 140 beats/min, and the blood pressure (BP) varies between 90/60 and 140/90 mmHg. Respirations are shallow, with a rate of 50/min. There is symmetric weakness of the face and all four extremities. Deep tendon reflexes are absent. Sensation is intact. Which of the following is the most likely diagnosis?

A 6-year-old boy is brought to the emergency department (ED) by the paramedics due to nausea, vomiting, diarrhea and abdominal pain over the past hour. His mother found an open multivitamin supplement bottle and some pills scattered on the kitchen floor. After his admission to the ED, he starts hyperventilating and experiences hematemesis. His blood pressure is 90/60 mmHg, pulse is 130/min, respirations are 50/min and temperature is 37.2 C (99F). Abdominal plain x-ray reveals several small opacities in the stomach and duodenum. Lab results are: Hb 13.5 g/dL, Ht 42%, WBC 10,000/mm3, Platelets 300,000/mm3, Blood Glucose 118 mg/dL, Serum Na 135 mEq/L, Serum K 34 mEq/L, Chloride 102 mEq/L, Bicarbonate 16 mEq/L, BUN 16 mg/dL, Serum Creatinine 1.0 mg/dL, pH 7.30, P02: 90 mm Hg, PC02: 29 mm Hg. What is the most likely diagnosis?

A 3-year-old boy is brought to the office by his mother because he has been having painless passage of black stools for the past few days. Otherwise, his bowel habits are normal. He has no other medical problems. He takes no medication. His vital signs are within normal limits. The physical examination is unremarkable. What is the most likely diagnosis of this patient?

A 2-week-old Caucasian male presents with constipation since birth. He was born full term via a normal vaginal delivery. He did not pass meconium till his 3rd day of life, after he was given a glycerin suppository. He has since stooled every 3–4 days, only with the help of a suppository. The stools are pellet like. He has had increasing abdominal distention. On rectal examination, tone appears normal and the ampulla contains no stool. Which of the following is the most likely cause?

A 44 year old woman delivers a 3120 g (6 lb 14 oz) newborn male. Her pregnancy was normal except that she noted decreased fetal movement compared to her previous pregnancies. She declined an amniocentesis offered by her obstetrician. Physical examination of the newborn reveals an infant with facial features suggestive of Down syndrome. The infant then has bilious vomiting. An x-ray film showing the kidneys, ureters, and bladder (KUB) is performed, which shows a "double bubble" sign. Which of the following is the most likely cause of the abdominal signs and symptoms?

A 9-year-old Caucasian male complains of fever, sore throat and difficulty swallowing. Small tender lymph nodes are palpated in the cervical region. The symptoms subside quickly on penicillin therapy. Ten days later, the patient presents again with fever, skin rash and fleeting joint pain in the lower extremities. Physical examination reveals scattered urticaria and palpable lymph nodes in the cervical, axillary and inguinal regions. Which of the following is the most likely cause of this patient's current complaints?

A 28-month-old female has been living with her mother in a shelter for homeless women and children. She is brought to the Emergency Department in status epilepticus, which is stopped with intravenous lorazepam. She is placed on a cardiac monitor and a wide complex tachycardia is noted. The ventricular tachycardia reverts to sinus tachycardia after defibrillation is performed. Her temperature is 38.5 C (101.3 F), blood pressure is 120/80 mm Hg, pulse is 195, and respirations are 26. Physical examination reveals a lethargic, pale toddler with dilated and reactive pupils, dry mucous membranes, shallow respirations, diaphoresis and brisk deep tendon reflexes. A urine toxicology screen is most likely to detect which of the following substances?

A 4-year-old girl is brought to the office due to seizures that occurred 2 hours ago. This is her first episode. Her parents are also concerned because she is not able to carry on activities that children of her age are expected to do. On examination, there is a red flat lesion covering the left eye area and adjacent facial skin, which does not blanch on pressure, and which the parents say has been present since birth. Other pertinent findings are hemianopia, hemiparesis, and hemisensory disturbances. An x-ray of the skull shows tramline intra-cranial calcifications. What is the most likely diagnosis?

A term neonate is small for date and has a small head. Further physical examination of the infant demonstrates small eyes with short palpebral fissures, a flattened nose, and abnormal palmar creases. With which of the following maternal conditions is this presentation most likely associated?

A 10-day-old infant is brought to the office by her mother for the evaluation of purulent discharge from both eyes. The discharge appeared three days ago, after which the child developed a cough. On examination, the infant's eyes appear normal, except for the presence of purulent discharge. Auscultation reveals diffuse rales without wheezing. Chest radiograph shows a hyperinflated thorax. What is the most likely diagnosis?

A 2-month-old girl presents to her pediatrician's office for well-child care. Her mother complains of excessive tearing of the baby's left eye for the past 4 weeks. Each morning, a yellow crusty discharge is noted along the lashes of the left eye. The conjunctiva appears uninflamed. The right eye is not affected. On physical examination, the infant is otherwise well and achieving adequate weight gain on an exclusive breast milk diet. She is developmentally appropriate, including visually tracking 180 degrees. Which of the following is the most likely diagnosis?

A 3-week-old female infant born at 38 weeks' gestation through an uncomplicated vaginal delivery, presents to the emergency department with 2-day history of fever. The infant had been healthy since birth. Her temperature in the emergency department is 40.0 C (104.0 F). She appears to be quite lethargic. A culture taken from the infant grows group B Streptococcus (GBS) in 24 hours. Which of the following infections is most consistent with this presentation?

A 10-year-old boy is brought to clinic because of increasing weakness and dyspnea over the past 6 months. He has been previously healthy and is on no medications. There is no significant family history of illness. On examination, he appears pale. His hematocrit is 20%, mean corpuscular volume (MCV) is 60/mm3, and iron level is normal. Smear reveals basophilic stippling. Hemoglobin electrophoresis is consistent with the absence of one beta-globin gene. Which of the following is the most likely diagnosis?

The child shown below presents with a 3-day history of malaise, fever to 41.1C (106F), cough, coryza, and conjunctivitis. He then develops the erythematous, maculopapular rash pictured. He is noted to have white pinpoint lesions on a bright red buccal mucosa in the area opposite his lower molars. Which of the following is the most likely diagnosis?

A 3-week-old infant with hypoplastic left heart syndrome comes to the physician for a follow-up visit. The infant was born at term via normal spontaneous vaginal delivery. The patient had the first of 3 palliative heart surgeries shortly after birth. He did well after surgery and was discharged home one week ago. Over the last 24 hours, the infant has difficulty feeding and one episodes of vomiting. On examination, the infant is afebrile, pulse is 160/min, respiratory rate is 55/min, blood pressure is 90/50mmHg, and pulse oximetry is 80% on room air. He is mildly cyanotic, small, but well developed. His cardiovascular exam reveals tachycardia and distant heart sounds with a systolic ejection murmur heard throughout the precordium. His chest radiographs from discharge and today are shown below. What is the most likely diagnosis?

A mother wishes to breast-feed her newborn infant, but is worried about medical conditions that would prohibit her from doing so. You counsel her that of her listed conditions, which of the following is a contraindication to breast-feeding?

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 6-day-old girl who was born at home is being evaluated for bruising and gastrointestinal bleeding. Laboratory findings include partial thromboplastin time and prothrombin time, greater than 2 minutes; serum bilirubin, 4.7 mg/dL; alanine aminotransferase, 18 mg/dL; platelet count, 330,000/mm3; and hemoglobin, 16.3 g/dL. Which of the following is the most likely cause of her bleeding?

A 1-year-old African American infant is in for well-child care. He is primarily breast-fed. His parents do not give him much solid food because he has no teeth. He receives no medications or supplements. His parents are concerned about his bowed legs. On examination, you note some other bony abnormalities including frontal bossing, enlargement of the costochondral junctions, a protuberant sternum (pigeon chest), and severe bowing of the legs. You obtain x-rays to confirm your clinical diagnosis and also note a healing fracture of the left femur. Which of the following is the most likely diagnosis?

A 14-year-old boy presents with sudden onset of pain and swelling of his right testicle. There was no history of trauma, he is not sexually active, and denies any history of penile discharge. On examination, the scrotum is swollen and tender. The cremasteric reflex is absent. A testicular flow scan shows a “cold spot” or absent flow to the affected side. Which of the following is the most likely cause?

A 28-year-old Caucasian female comes to the office due to fever for the past 3 days. She also complains of pain and swelling in her right breast for the past 4 days. She exclusively breastfeeds her 3-month-old baby. On examination, she is febrile. Her right breast is engorged, red and tender, without any area of fluctuation. She wants to know if she can continue to breastfeed. Which of the following is a contraindication to breastfeeding?`

Among the conditions that cause edema of the eyelids is orbital cellulitis. This is a serious infection that must be recognized early and treated aggressively if complications are to be avoided. Which of the following features is useful in differentiating orbital cellulitis from periorbital (preseptal) cellulitis?

A 30-minute-old male newborn is noted to have central cyanosis. He was born to a 16-year-old white female at 28 weeks gestation. His respirations are rapid and shallow at 70/min. His other vital signs are stable. On examination, there is audible grunting, intercostal and subcostal retractions, nasal flaring, and duskiness. On auscultation, fine rales are heard over the lung bases. Nasal oxygenation does not improve his cyanosis. A chest roentgenogram shows fine reticular granularity, predominantly in the lower lobes. Arterial blood gas analysis shows evidence of hypoxemia and metabolic acidosis. What is the most likely diagnosis of this patient?

A 10-year-old patient (pictured below) calls his parents from summer camp to state that he has had fever, muscular pain (especially in the neck), headache, and malaise. He describes the area from the back of his mandible toward the mastoid space as being full and tender and that his earlobe on the affected side appears to be sticking upward and outward. Drinking sour liquids causes much pain in the affected area. When his father calls your office, you remind him that he had refused immunizations for his child on religious grounds. Which of the following preventable diseases has this child acquired?

A healthy 1-year-old child comes to your office for a routine checkup and for immunizations. His parents have no complaints or concerns. The next day, the CBC you performed as customary screening for anemia returns with the percentage of eosinophils on the differential to be 30%. Which of the following is the most likely explanation?

Two weeks after a viral syndrome, a 2-year-old child develops bruising and generalized petechiae, more prominent over the legs. No hepatosplenomegaly or lymph node enlargement is noted. The examination is otherwise unremarkable. Laboratory testing shows the patient to have a normal hemoglobin, hematocrit, and white blood cell (WBC) count and differential. The plateletcount is 15,000/μL. Which of the following is the most likely diagnosis?

A 30-minute-old male newborn is noted to have central cyanosis. He was born to a 16-year-old white female at 28 weeks gestation. His respirations are rapid and shallow at 70/min. His other vital signs are stable. On examination, there is audible grunting, intercostal and subcostal retractions, nasal flaring, and duskiness. On auscultation, fine rales are heard over the lung bases. Nasal oxygenation does not improve his cyanosis. A chest roentgenogram shows fine reticular granularity, predominantly in the lower lobes. Arterial blood gas analysis shows evidence of hypoxemia and metabolic acidosis. What is the most likely diagnosis of this patient?

Friends are considering adopting a “special needs” child from another country. The family has few details, but the information they have received so far suggests the 4-year-old child has had surgery for an endocardial cushion defect, is short for his age, and had a history of what sounds like surgically repaired duodenal atresia at birth. You are suspicious this child may have which of the following syndromes?

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 1400-g infant, born at 35 weeks' gestation, is 42 cm in length and a head circumference of 28 cm. One day after birth, she becomes very irritable, tremulous, and inconsolable. Her cry is high-pitched. Her pulse is 174/min. There are no dysmorphic facial features. To which of the following substances was this newborn most likely exposed in utero?

A 16-year-old female presents to the emergency room with severe right- sided abdominal pain. Her last menstrual period was 2 weeks ago and felt to be normal. She displays painful difficulty in positioning herself on the examination table. Her temperature is 38.5 C (101.3 F), blood pressure is 128/75 mm Hg, pulse is 80/min, and respirations are 22/min. Examination of the throat reveals mild pharyngitis. Her abdomen is diffusely tender, especially the lower abdomen. Rectal examination reveals tenderness anteriorly on the right side. Stool guaiac is negative. A pelvic examination is performed, and there is evidence of cervical tenderness and questionable fullness in the right adnexal area. Which of the following is the most likely diagnosis?

The mother of one of your regular patients calls your office. She reports that her daughter has a 3-day history of subjective fever, hoarseness, and a bad barking cough. You arrange for her to be seen in your office that morning. Upon seeing this child, you would expect to find which of the following?

A 2 and a half-year-old child is brought to the office for the evaluation of easy bruising, nosebleeds, and decreased activity over the past week. He had an upper respiratory infection that was treated with an antibiotic 2 weeks ago. On examination, he is well-developed, seems well-nourished, anicteric, and pale. Pertinent findings include some small palpable posterior cervical lymph nodes, sinus tachycardia, a grade I/VI systolic ejection murmur, ecchymoses on his left shoulder and both lower extremities, and petechiae over his extremities and groin. There is no hepatosplenomegaly. The laboratory findings are as follows: Hemoglobin 7.9 g/dl, Hematocrit 24%, Platelet count 12, 000/mm3, WBC 3,000/mm3, Reticulocyte count 0.5%. A bone marrow biopsy reveal a markedly hypocellular marrow with decreased megakaryocytes and precursors of the erythroid and myeloid cell lines. What is the most likely diagnosis?

The parents of a 16-year-old girl bring their daughter to the Emergency Department due to their concerns regarding her recent behavior. Her mother reports, “She has always been a straight “A” student and has had an uneventful childhood until now.” Her developmental and medical history are insignificant except for a diagnosis of asthma when she was eight-years-old. Over the last two months, she has been spending time with new friends, dressing differently, and has become increasingly defiant. This morning, her parents received a call from her school counselor who reported that the patient missed three days of school last week and is in danger of having to attend next course because she is falling math. Last night, she did not return home until 3 am despite the fact that her curfew was 11 pm. The patient is annoyed and states, “What’s the big deal? I was just hanging out with my friends.” Initially, she refused to answer any questions. Her cooperation improves, however, when assessed without her parents present. Review of symptoms was negative and she confirms that her asthma was controlled. She denies abusing any substances. She confirms that her grades have dropped because she is tired of school. She also says, “I really don’t care if I fail, but I’m not going to next course. Me and my friends have plans.” She would not provide any further details. After interviewing both the parents and the adolescent individually, which of the following is the most appropriate course of action?

A worried and anxious pregnant mother brings her 3-year-old son to the emergency room after he experienced several episodes of vomiting and abdominal pain for the past two hours. His vomit is coffee ground in appearance. He is irritable and lethargic. His BP is 80/40 mmHg and pulse rate is 120/min. Examination shows a normal oropharynx; chest auscultation is within normal limits. Abdomen is soft and mildly tender at the epigastrium; there is no hepatosplenomegaly. Extremities are cold to touch. Initial laboratory studies show: Hemoglobin 10.3 g/L, Leukocyte count 14, 500/mm3, Bicarbonate 18 mEq/L. Chest x-ray is normal limits. Abdominal imaging shows radiopaque tablets in the stomach. Intravenous normal saline is started. Which of the following is the most appropriate next step in management?

A 12-year-old African American male with known sickle cell disease presents with a 2 hours history of right-sided arm weakness ans slurred speech. He has been hospitalized before for pain crises and pneumonia. He takes hydroxyurea, oxycodones as needed, and folic acid. His temperature is 36.6 C, BP is 153/83 mmHg and HR is 112/min with regular rhythm. On physical examination, he has right arm weakness and mild dysarthria. His laboratory values are the following: Hemoglobin 8.2 mg/dL, WBC count 14, 000.mm3, Platelet count 210, 000/mm3, Creatinine 0.9 mg/dL. CT of the head shows no evidence of intracranial bleeding. Which of the following is the best initial management for this patient?

A 1-day-old full-term boy is in the neonatal intensive care unit with cyanosis. His BP is 80/40 mmHg in all 4 extremities, HR is 140/min, and respirations are 55/min. Pulse oxymetry shows 80% and does not improve with 100% inspired oxygen by face mask. He is breathing comfortably, but his fingertips and oral mucosa are blue. A continuous machine-like murmur is heard on auscultation. Chest x-ray shows clear lung fields bilaterally. Which of the following is the best next step in management of this patient?

A 3-year-old boy is brought to the physician for help with toilet training. He recently started day care and screams "no" when teachers try to place him on the toilet. He has bowel movements every other day and strains when he passes hard, pellet-like stools. The boy is a picky eater but loves milk and drinks up to 30 oz of chocolate milk daily. He has no medical problems and takes no medications. His weight and height have been tracking along the 75th percentile. Examination shows a cooperative, well-nourished boy. He runs well and can climb onto the examination table independently. He speaks in short sentences that are mostly understandable. The boy's abdomen is soft, nontender, and nondistended. He has normal Tanner I male genitalia. A small fissure is noted on the anal verge. Which of the following is the best next step in management of this patient?

A 6-week-old girl comes to medical attention because of a bright red plaque on her neck. The plaque is slightly raised, measures 2 cm in greatest diameter, and blanches partially on pressure. The mother reports that the lesion appeared in the second or third week and has been gradually increasing in size. Which of the following is the most appropriate next step in management?

You are examining a newborn infant in the well-baby nursery. The infant was the product of a benign pregnancy and vaginal delivery; he appears to be in no distress. Interestingly, your measurement of fronto- occipital head circumference is about 2 cm larger than the initial measurement done several hours before. Your examination otherwise is significant for tachycardia and a “squishy” feel to the entire scalp. You can elicit a fluid wave over the scalp. Management of this condition should include which of the following?

A 5-year-old boy is brought to his pediatrician's office after he falls from his bicycle and strikes his head against the sidewalk. There were no witnesses to this incident, which occurred 8 hours ago. The child is otherwise healthy, up-to-date on his immunizations, and not taking any medications. On physical examination, his vital signs are stable. He has a 5 × 4 cm abrasion on his forehead. He is alert and oriented to date, place and self. His motor and sensory examinations are normal and reflexes are normal. Which of the following constitutes reasonable management?

The parents of a 16-year-old girl complain that she does not get enough sleep. They recently discovered that she stays awake most nights until 1:00 AM reading and text messaging her friends. She wakes at 6:30 AM for school, and complains of sleepiness during the day. On weekends she sleeps until noon. Her parents have tried taking away her computer and phone, but she still would go to bed at the same time. The parents are looking for advice in dealing with their “night owl” daughter. Which of the following is appropriate advice for this family?

A 15-year-old boy comes to the physician for advice about his facial acne. On examination, the patient has mild to moderate acne, mostly consisting of open comedones, some closed comedones, and a few pustules on the forehead and cheeks. Which of the following is the best advice to give this patient?

A female infant is born full-term to a 24-year-old Caucasian primigravida. The delivery was uncomplicated. The Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. The prenatal course was complicated with asymptomatic bacteriuria that was treated with an antibiotic. The mother took multivitamins during her last trimester, occasionally took acetaminophen for back pain throughout the pregnancy, and denies smoking and alcohol consumption. Physical examination of the infant reveals a blood-tinged vaginal discharge and bilaterally enlarged mammary glands. What is the best next step in the management of this patient?`

The mother of a 2-year-old girl reports that her daughter complains of burning when she urinates and that she has foul-smelling discharge from her vagina. She has some slight staining on the front of her underwear, but denies fever, nausea, vomiting, or other constitutional signs. The child does not attend day care, and she has demonstrated no change in behavior. The physical examination is normal with an intact hymen, but the child’s vulva is reddened and with a malodorous scent noted. Her urinalysis and culture are normal. Management of this condition includes which of the following?

A 12-year-old boy comes to the emergency department at midnight with a complaint of severe scrotal pain since 7 PM. There is no history of trauma. Which of the following is the most appropriate first step in management?

A 12-year-old boy presents with an intensely pruritic rash for 3 days. He just went on a camping trip, during which he wore only short-sleeve shirts and short pants. His temperature is 37.6 C (99.7 F), blood pressure is 96/62 mm Hg, pulse is 65/min, and respirations are 12/min. There are numerous erythematous papules and vesicles on both arms and legs. Most of them are in a linear array. Which of the following is the most appropriate pharmacotherapy?

A 5-year-old boy suddenly begins coughing while eating peanuts. He is choking and gagging. When he is brought to the emergency department, but he is awake and is able to give his name. On physical examination, his vital signs are stable. On examination of the chest, inspiratory stridor and intercostal and suprasternal retractions are apparent. Which of the following is the most appropriate initial step in management?

A 9-year-old boy is rushed to the emergency department after having a seizure. He is visiting his grandparents for the weekend. His past medical history is insignificant. When the grandmother is questioned about any medications, she replies with, "He isn't taking any medications, but I'm taking nortriptyline, and my husband is taking atenolol and enalapril." The boy's blood pressure is 80/40 mmHg and pulse is 90/min. Physical examination reveals dry oral mucosa and dilated pupils. His answers are adequate, but delayed. EKG shows wide QRS complexes. What is the best next step in the management of this patient?

A 1-month-old infant is brought to the office for a routine neonatal visit. His prenatal and birth histories are unremarkable. His vital signs are normal. Examination reveals a harsh, loud holosystolic murmur over the left, lower sternal border. Palpation reveals a thrill over the precordial region. There is no cyanosis, and pulmonary auscultation reveals no rales. Chest radiograph reveals a heart of normal size and a slight increase in pulmonary vascularity. EKG is normal. Which of the following is the most appropriate course of action?

A 19-year-old male college student returns from spring break in Fort Lauderdale, Florida, with complaints of acute pain and swelling of the scrotum. Physical examination reveals an exquisitely tender, swollen right testis that is rather hard to examine. The cremasteric reflex is absent, but there is no swelling in the inguinal area. The rest of his genitourinary examination appears to be normal. A urine dip is negative for red and white blood cells. Which of the following is the appropriate next step in management?

A 7-day-old female neonate is brought to your office for a 2-day history of jaundice and poor feeding. According to the mother, she has vomited twice but doesn't appear febrile. She is regularly breastfed. Her birth history is unremarkable. On examination, she appears listless, and mild jaundice, along with signs of dehydration, are noted. Her blood pressure is 78/52mm Hg, pulse rate is 150/min, and temperature is 36 C (96 F). Her family history is insignificant. What is the most appropriate next step in the management of this patient?

The father of a 1-week-old infant comes to the office in a panic. He has just noticed on his child a right anterior shoulder mass that seems ten- der. The father is an osteosarcoma survivor and fears the child has the same malignancy. In reviewing the baby’s discharge papers, you note the child was a term, appropriate-for-gestational-age vaginal delivery with a birth weight of 3200 g (7 lb, 1 oz). Apgar scores were 9 at 1 and 5 minutes. Your examination is significant for a large firm mass on the right clavicle; the rest of the examination is normal. Management of this problem should include which of the following?

A 7-year-old girl complains of increased urinary frequency, dysuria and itching on urination. Her urinalysis is consistent with a urinary tract infection. This is her 20th infection in the past year, despite adequate antibiotic coverage. Further imaging of her bladder, kidneys and ureter reveals is consistent with vesicoureteral reflux. Which of the following is the next appropriate step?

A 3-year-old girl is believed to have swallowed a marble. She presents to the emergency department unable to speak and begins to become cyanotic. Initial attempts at endotracheal intubation are unsuccessful. Which of the following is the most appropriate next step in management?

A previously normal newborn infant in a community hospital nursery is noted to be cyanotic at 14 hours of life. She is placed on a face mask with oxygen flowing at 10 L/min. She remains cyanotic, and her pulse oximetry reading does not change. An arterial blood gas shows her PaO2 to be 23 mm Hg. Bilateral breath sounds are present, and she has no murmur. She is breathing deeply and quickly, but she is not retracting. While you are waiting for the transport team from the nearby children’s hospital, you should initiate which of the following?

A mother brings her 4-year-old son to see you. She seems to be very concerned about her child's bedwetting. As you explore the history, the mother tells you that she started his toilet training when he was 2 years old. The child responded to his mother's efforts and slowly was able to reduce the frequency of bedwetting. However, he did not completely succeed and still occasionally wets his bed. She has become so concerned that she demands you to order tests and prescribe some drugs to resolve the problem. What is your best next step in the management of this boy?

A 20-year-old female is brought to the Emergency Room by her college roommate who states that the patient vomited all night. The patient complains of a sore throat and says she has not eaten for the last two days. She admits to a "sugar problem" and quit taking her medication because she has not been eating. Examination reveals an ill-appearing woman. Her temperature is 37.9 C (100.2 F), blood pressure is 118/78 mm Hg, pulse is 160/min, and respirations are 30/min. The patient's lips and mucous membranes are dry. There is a fruity odor noted to the patient's breath. The lung and cardiac examination are unremarkable except for mild tachypnea and tachycardia. Laboratory analysis shows: Sodium 130 mEq/L, Potassium 6.1 mEq/L, Chloride 100 mEq/L, Bicarbonate 8 mEq/L, Urea nitrogen 10 mg/dL, Creatinine 1.0 mg/dL, Glucose 680 mg/dL, pH 7.15, pCO2: 30 mm Hg, pO2: 85 mm Hg, Urinalysis is positive for ketones. Which of the following is the most appropriate initial step in management?

A new mother complains that her 6-week-old infant frequently regurgitates small volumes of formula during and after feedings. Physical examination demonstrates a happy baby who has gained half a pound since his last visit. No abdominal masses are noted. Which of the following is the best next step in management?

A 3-year-old girl presents to the pediatrician's office. The mother states that the girl has been having big, bulky stools that float in the toilet. She also has intermittent diarrhea. On examination, her height is 88 cm (34.6 in, <5th percentile) and weight is 15.8 kg (34.8 lb, <5th percentile). In addition, she has an uncle who died of recurrent lower respiratory infections. Which of the following would be most effective for alleviating the gastrointestinal symptoms of this patient?

A 14-year-old girl with a history of seizures is admitted to the hospital with the diagnosis of status epilepticus. Her valproic acid level is in the therapeutic range. You arrange a 24-hour video electroencephalogram (EEG). During the EEG, she has several episodes of tonic and clonic movements with moaning and crying, with no loss of bowel or bladder control. The neurologist tells you that during the events the EEG had excessive muscle artifact but no epileptiform discharges. Which of the following treatments is the most appropriate for this condition?

A 5-year-old African-American boy is brought to the office by his mother due to a painful right knee, fever and chills over the last 2 days. The child was diagnosed with pharyngitis 2 weeks ago, and was treated with a 10-day course of penicillin G. His temperature is 38.8 C (102F) and pulse rate is 102/min. On examination, his right knee joint is swollen and erythematous, with a decreased range of motion. The laboratory findings are significant for leukocytosis and an elevated ESR. X-rays of both the right hip and knee joints are normal. What is the most appropriate treatment for the patient's condition?

A 12-year-old boy comes to the emergency department with severe shortness of breath, cough, and fever. He was diagnosed with cystic fibrosis when he was five years old. He is currently not taking any medications. His temperature is 39.4 C (103F), blood pressure is 80/40 mmHg, pulse is 120/min, and respirations are 30/min. He is excessively using his accessory respiratory muscles. Lung auscultation reveals bilateral lower lobe crackles and expiratory wheezing. Pulse oximetry shows Sa02 of 85% that improves to 92% after oxygen supplementation. Which of the following antibiotics or combinations is the best choice for this patient?

7-month-old boy is brought to his physician because of increased agitation and restlessness. Lung examination reveals crackles and decreased breath sounds bilaterally. Chest x-ray films are notable for bilateral pneumonia. Arterial blood gas analysis reveals an oxygen tension of 45 mm Hg and a carbon dioxide tension of 60 mm Hg. Which of the following is the most appropriate next step in management?

You have just given a 10-year-old boy an injection of pollen extract as prescribed by his allergist. You are about to move on to the next patient when the boy starts to complain about nausea and a funny feeling in his chest. You note that his face is flushed and his voice sounds muffled and strained. Which of the following is the first priority in managing this episode of anaphylaxis?