( New ) Part 7 (1597- 1629) (1530- 1784) PogbaKH 3

A 5-year-old boy suffers from a condition characterized by recurrent fungal and viral infections, thymic hypoplasia, tetany, and abnormal facies. Serum levels of immunoglobulins are mildly depressed, and lymph node biopsy shows lymphocyte depletion of T-dependent areas. Which of the following is the underlying pathogenetic mechanism?

While working in the newborn nursery, you have the chance to counsel a first time mother. She had a healthy pregnancy and good prenatal care. The infant was delivered via normal spontaneous vaginal delivery and is doing well. You are counseling the mother on the benefits of breastfeeding, and she asks you what the differences are between human milk and formula. Which of the following is a true statement?

A newborn is diagnosed with congenital heart disease. You counsel the family that the incidence of heart disease in future children is which of the following?

An otherwise healthy 13-year-old boy has seasonal allergic rhinitis. He complains of excessive rhinorrhea, frequent sneezing, and nasal congestion. He has a nasal voice and breathes with his mouth. He derives some relief from keeping windows closed at home and spending as litde time as possible outdoors in periods of high pollen concentration. However, he is excessively bothered by nasal congestion. Which of the following drugs would be most effective in relieving nasal congestion?

A 7 -year-old Caucasian boy is brought to the emergency room with a severe headache, vomiting, and altered mental status of acute onset. His temperature is 36.7 C (98 F), blood pressure is 130/70 mm Hg, pulse is 60/min, and respirations are 18/min. Neurologic examination reveals nuchal rigidity, but no focal neurologic signs. A CT scan shows blood in the subarachnoid space. Which of the following is the most probable additional finding in this patient?

A 3-year-old boy is brought to the office by his parents for the evaluation of dry eyes and photophobia. He has some difficulty in adapting to darkness. He is a very poor eater, and his diet consists mainly of canned foods, and very rarely, fresh vegetables or milk. Examination reveals dry, scaly skin, follicular hyperkeratosis in the extensor surfaces of the extremities, and dry, silver-gray plaques on the bulbar conjunctiva. What is the most likely diagnosis of this patient?

An infant is due for her first dose of polio vaccine. Her parents have heard that there are two different types of vaccine for polio. They want to know why their daughter needs to get another shot rather than just taking the oral form of the vaccine. You tell the parents the major advantage of the injectable vaccine is which of the following?

An infant can regard his parent’s face, follow to the midline, lift his head from the examining table, smile spontaneously, and respond to a bell. He does not yet regard his own hand, follow past the midline, nor lift his head to a 45° angle off the examining table. Which of the following is the most likely age of the infant?

A child is brought to your clinic for a routine examination. She can put on a T-shirt but requires a bit of help dressing otherwise. She can copy a circle well but has difficulty in copying a square. Her speech is understandable and she knows four colors. She balances proudly on each foot for 2 seconds but is unable to hold the stance for 5 seconds. Which of the following is the most likely age of this child?

A 16-year-old boy with a history of ulcerative colitis presents to the physician complaining of diarrhea and a rash. He states that his appetite has been decreased recently, and also complains of nausea and abdominal pain in addition to watery diarrhea. He has an erythematous rash on his distal arms and legs that "burns". His mother reports that he has had poor concentration and has been irritable lately. Vital signs are stable. Examination reveals a beefy red tongue that appears swollen. Abdominal examination is normal. The rash resembles a sunburn and is located on his distal arms and legs. It is symmetrical and tender to palpation. Neurological examination is normal. This patient's symptoms are most likely due to a deficiency of which of the following vitamins?

A full-term infant is brought to the office on her 6th day of life because her mother noted that she looked "yellow". The mother states that the infant is strictly breast-fed and has been eating every 2-3 hours. On examination, she is noted to be jaundiced over her trunk and face. There is no scleral icterus. She is otherwise healthy. Both the mother and baby are Rh positive. Which of the following is the most likely cause of this infant's jaundice?

A 5-year-old pedestrian is hit by a car in a mall parking lot and he is brought to the emergency department. There was loss of consciousness for less than 1 minute. On evaluation, the child has no neurologic deficits and a CT scan of the head reveals no intracranial abnormalities and no obvious skull fractures. The parents want to know what possible long-term problems there might be. You remember that problems after head trauma may include the development of seizures and that the risk of developing posttraumatic epilepsy is increased by which of the following?

A one-year-old girl is brought to the office for the evaluation of sickle cell anemia. Both her parents have sickle cell trait, and her elder sister has sickle cell anemia. Her vital signs are stable. Her height and weight are appropriate for age. On examination, she appears healthy and normal. Her birth and past medical histories are insignificant. Hemoglobin electrophoresis reveals 40% hemoglobin S. What is the most common presentation of this condition?

A boy is brought to the office by his parents for a routine visit. During the physical examination, he can obey two-step commands, use two- to three-word phrases, and can build a tower of six blocks. According to his mother, he can walk up and down the stairs without help. What is the most likely age of this child?

A 12-year-old boy is brought to the emergency department because of severe pain near his left knee. He has sickle cell disease and has been hospitalized previously for sickle cell crisis. Vital signs are notable for persistent fever. Examination of the left lower extremity reveals a normal knee joint with marked tenderness and swelling over the proximal tibia. Laboratory studies show leukocytosis and elevated ESR. Imaging studies confirm the diagnosis of osteomyelitis. Which of the following organisms is the most likely cause of his condition?

A child is brought to the physician for a routine visit. On examination, the child can name multiple items in the examination room, and can also combine 2 words into a short sentence. His mother estimates that he knows about 200 words. When his mother tries to help him onto the examination table, he says "me do it." Although his mother seems to understand most of what he says, you can only understand about half of his speech. Which of the following is the most likely age of this child?

A 2-year-old boy is brought to the office by his mother because he has not started to walk yet. His birth history is significant for prolonged labor, and his APGAR scores at 1 and 5 minutes were 3 and 5, respectively. His older brother is 4 years old, and has a normal developmental history. On examination, the child has hypotonia, learning disabilities and hyperactive deep tendon reflexes. What is the most likely cause for the child's delayed milestones?

A 2-year-old boy is brought to the office by his parents due to severe diarrhea since yesterday. He has had approximately 20 episodes of non-bloody, non-mucoid stool passage in the last twenty hours, and one episode of bilious vomiting. He is also feeding less than usual. He is febrile, tachycardic and moderately dehydrated. What is the most likely cause of his presentation?

Routine examination of an otherwise healthy kindergarten child with a history of asthma reveals a BP of 140/90 mmHg. Which of the following is the most likely cause of the hypertension?

A 6-year-old boy is seen in the office for evaluation of polyuria. Further questioning reveals several months of headache with occasional emesis. Your physical examination reveals a child who is less than 5% for weight. He has mild papilledema. His glucose is normal, and his first urine void specific gravity after a night without liquids is 1.005 g/mL. Which of the following might also be expected to be seen in this patient?

A 2-year-old girl is brought to the clinic due to fever, irritability and lethargy for the past two weeks. Over the past two months, she has complained of intermittent abdominal discomfort and has lost weight. Abdominal palpation reveals a firm nodular mass in the right flank. No bruits are heard. Abdominal x-ray reveals multiple calcifications in the renal area. Urine examination reveals increased levels of homovanillic acid and vanillylmandelic acid. Which embryonic structure has this mass most likely arisen from?

59) A 9-year-old boy is brought to the emergency department due to an episode of seizures during class. His teacher says that the seizure started suddenly, and he fell to the ground with sustained flexion of the arms and extension of the legs, followed by clonic movements of the whole body. He has also been irritable lately, and his school performance has declined. His parents arrive shortly and say that they recently noticed he was lethargic and frequently complained of headaches, especially in the morning. His medical history is unremarkable. Physical examination reveals decreased muscle strength of the left side of the body, with brisk deep tendon reflexes in the left arm and leg. MRI of the head reveals a space-occupying lesion in the right parietal lobe. What tumor is most likely responsible for this patient's symptoms?

A 2-year-old boy is brought to the pediatrician for a routine well-child visit. He has been growing and developing normally. He is starting to put words together into 2-word phrases. The boy eats a variety of foods including meats, vegetables, and fruits, and drinks 24-28 ounces (700ml) of whole milk each day. Past medical history is unremarkable. His mother has no concerns at today's visit. His physical examination is within normal limits. Laboratory results are as follows: Complete blood count: Hemoglobin 9.4 g/dl, Hematocrit 28%, Mean corpuscular volume 64 fl, Red cell distribution width 14% (normal 11.5%-16.0%), Reticulocytes 3.0%, Platelets 240,000/μL, Leukocytes 7,500/μL, Blood, plasma, and serum, Ferritin 100 ng/ml (7-140 ng/ml), Iron-binding capacity 300 μg/dl (240-450 μg/dl). Which of the following is the most likely cause for this child's anemia?

A newborn is noted to be quite jaundiced at 3 days of life. Laboratory data demonstrate his total bilirubin to be 17.8 mg/dL (direct bilirubin is 0.3 mg/dL). Which of the following factors is associated with an increased risk of neurologic damage in a jaundiced newborn?

A 6-year-old boy is brought to the clinic for the evaluation of a large, red, circular rash on his left thigh which has been present since two weeks and has been enlarging. He has a mild headache and myalgia, but is afebrile. Three weeks ago, he and his family visited relatives at a rural farm in Connecticut and went hiking in the woods. His temperature is 37.2 C (99 F) and pulse is 90/min. He is alert, active, appears non-toxic, and not in distress. On the anterior surface of his left thigh, there is a red ring that is 7 cm in diameter with central clearing, and a central brownish-red macule that is 3 mm in diameter. Which of the following measures would have prevented this condition?

63) A 1-week-old female infant is brought to the office by her 30-year-old African-American mother because she has been "crying a lot." She was born at term. Her mother was diagnosed with gestational diabetes mellitus (GDM) at 24 weeks gestation and had been on insulin injections since. During labor, there was a prolonged second stage due to difficulty in delivering the shoulders. Her Apgar scores were 8 and 10 at 1 and 5 minutes, respectively. Her birth weight is 3.8 kg (8.5 Ib). On examination, the infant is active. On sudden extension of the head, there is extension of all the extremities, except for the left upper extremity. There is crepitus over the left clavicular bone. Which of the following statements is true for this baby?

64) A 12-month-old patient has allergies to multiple foods. The child’s mother has eliminated the foods from the diet and wants to know if these allergies will be lifelong. You tell her that some allergies do get better if the food is eliminated for 1–2 years. In which of the following is the allergy most likely to resolve, with elimination of the food from the diet?

65) A 9-year-old boy is brought to the emergency department by his father due to a sudden onset of difficulty with writing and jerky movements. He recently had a mild sore throat which quickly resolved, but now seems to have recurred and have worsened. He also had a low-grade fever last week, but no chills. Physical examination reveals a pericardial friction rub and subcutaneous nodules over the hands. Laboratory studies show an elevated ESR. What is the most likely cause of this child's symptoms?

66) An 18-month-old girl is brought to the hospital with a history of 6 days of bloody diarrhea. She has been drinking well but has not been wetting her diaper. She has been irritable. On physical examination, she has periorbital edema. She appears pale and is tachycardic. Her CBC shows a hemoglobin of 6 g/dL and a platelet count of 100,000/mm3. Her blood urea nitrogen (BUN) is 50 mg/dL and creatinine is 5.5 mg/dL. Her urinalysis shows gross hematuria. Which of the following is the most likely causative organism for her clinical problem?

67) A 1-year-old child with ALL in remission for 3 months is in the office for a health maintenance visit. He is due for multiple vaccinations including hepatitis B vaccine, inactivated polio vaccine (IPV), varicella vaccine H. influenzae B vaccine (Hib), and pneumococcal vaccine (PCV). You remember that some of these vaccines are live attenuated viruses and are contraindicated in immunocompromised patients. Which vaccine will you not give to this patient?

68) A 3-month-old Jewish infant is brought to the emergency department because of a generalized seizure 1 hour ago. He is lethargic, weighs 2.7kg (61b), and has a doll-like face with fat cheeks, relatively thin extremities, and a protuberant abdomen. His liver is felt 5cm (2in) below the right costal margin. His kidneys are enlarged. His blood sugar level is 40mg/dl. His serum uric acid, total cholesterol, triglycerides and lactic acid levels are elevated. The levels of his liver transaminases are normal. What is the most likely cause of this infant's symptoms?

69) A 4-year-old girl is brought to the physician because of a crusted honey-colored erythema resulting from rupture of tiny vesicles and pustules. Her temperature is 37.7 C (102 F). Skin lesions are distributed over the face and extremities. Physical examination reveals enlargement of lymph nodes in the cervical and axillary regions. Which of the following is the most frequent pathogen of this skin infection?

70) A 4-month-old baby is in for a well-child check and routine immunizations. The baby had a fever of 39°C the day he received his 2-month immunizations. The parents have read about the vaccine on the Internet and express their concerns. Which of the following is an absolute contraindication to giving the diphtheria and tetanus toxoids and acellular pertussis (DTaP)?

71) A 4-day-old boy is brought to the physician for an outpatient follow-up visit. His mother's pregnancy and delivery were uncomplicated. The patient weighed 3.4 kg (7.5 lb) and was 48.2 cm (1'7") long at birth. He did well in the newborn nursery and was discharged from the hospital on day 2 of life. His mother reports that he is now exclusively breastfed and nurses for 10 minutes on each breast every 3 hours. He has two wet diapers/day and has not had a bowel movement for 2 days. He weighs 2.95 kg (6.5 lb) and is 48.2 cm (1'7'') long. He appears jaundiced on the face and chest. The remainder of the physical examination shows no abnormalities. Laboratory studies reveal: Total bilirubin 15 mg/dl, direct bilirubin 1 mg/dl, Infant's blood type 0 positive, Mother's blood type A positive. Which of the following is the most likely cause of this infant's hyperbilirubinemia?

72) A 1-week-old infant is brought to the emergency department due to vomiting and poor feeding. The prenatal and birth histories are unremarkable. The infant's pulse is 140/min, temperature is 37 C (98.7 F), and capillary refill is 2 sec. He has sunken eyes, depressed anterior fontanel, and dry mucus membranes; skin elasticity is reduced. Heart and lungs are clear. There is no abdominal mass. Genital examination shows enlarged clitoris, and fusion of the labioscrotal folds. The initial laboratory work-up reveals the following: Sodium 128 mEq/L, Potassium 5.8 mEq/L, BUN 25 mg/dl. If this patient's karyotype is 46 XX, which of the following is most likely to be increased in this patient's serum?

73) A 6-year-old African-American child is brought in by his father for complaints of easy fatigability and pallor. These symptoms occurred after the son was treated with "some medication" for a recent diarrhea. Physical examination is normal except for pallor and multiple petechiae. Laboratory values are as follows: Hb 8.0 g/dL, WBC 12,000/mm3, Platelets 50,000/mm3, Blood glucose 118 mg/dL, Serum Na 135 mEq/L, Serum K 5.3 mEq/L, Chloride 110 mEq/L, Bicarbonate 18 mEq/L, BUN 38 mg/dL, Serum creatinine 2.5 mg/dL, Total bilirubin 3 mg/dL, Direct bilirubin 0.5 mg/dL, PT 12 seconds, APTT 30 seconds, LDH 900 IU/L, Reticulocyte count 6%. A peripheral blood smear reveals giant platelets and multiple schistocytes. What is the most likely underlying pathophysiology for this boy's pallor?

74) A 4-year-old previously well African American boy is brought to the office by his aunt. She reports that he developed pallor, dark urine, and jaundice over the past few days. He stays with her, has not traveled, and has not been exposed to a jaundiced person, but he is taking trimethoprim sulfamethoxazole for otitis media. The CBC in the office shows a low hemoglobin and hematocrit, while his “stat” serum electrolytes, blood urea nitrogen (BUN), and chemistries are remarkable only for an elevation of his bilirubin levels. His aunt seems to recall his 8-year-old brother having had an “allergic reaction” to aspirin, which also caused a short-lived period of anemia and jaundice. Which of the following is the most likely cause of this patient’s symptoms?

75) A 24-month-old child is seen in the pediatrician's office for a regular health supervision visit. He has no history of developmental delay. He was born by an uncomplicated normal vaginal delivery at term, and he has not had any significant illness or injury prior to this visit. Which of the following motor milestones is most consistent with his age?

76) A 2-year-old girl has severe dental caries of the upper and lower incisors. Her teeth are brushed twice daily with a small amount of fluoride-containing toothpaste. What is the feeding practice most likely to result in this pattern of dental caries?

77) A 3-year-old boy is brought to the emergency department three hours after having a seizure. He has been having severe diarrhea for the last three days. His mother recently read about the importance of maintaining adequate hydration during diarrhea, so she had been giving him a lot of milk mixed with water. On examination, his vital signs are stable and mucus membranes are moist. Initial lab results are: Hb 13 g/dl, WBC 6,000/mm3, Platelets 300,000/mm3, Blood Glucose 98 mg/dl, Serum Na 120 mEq/L, Serum K 3.4 mEq/L, Chloride 92 mEq/L, BUN 22 mg/dl, Creatinine 1.2 mg/dl. What is the most likely cause of this patient's seizure?

78) The state laboratory calls your office telling you that a newborn infant, now 8 days old, has an elevated thyroid stimulating hormone (TSH), and low thyroxin (T4) on his newborn screen. If this condition is left untreated, the infant is likely to demonstrate which of the following in the first few months of life?

79) A 1-year-old boy presents with the complaint from his parents of “not developing normally.” He was the product of an uneventful term pregnancy and delivery, and reportedly was normal at birth. His previous health-care provider noted his developmental delay, and also noted that the child seemed to have an enlarged spleen and liver. On your examination, you confirm the developmental delay and the hepatosplenomegaly, and also notice that the child has short stature, macrocephaly, hirsutism, a coarse facies, and decreased joint mobility. Which of the following is the most likely etiology of his condition?

80) A 22-year-old Caucasian female who has received no prenatal care experiences a stillbirth. This is her first pregnancy. The baby has multiple fractures, blue sclerae and short, bent extremities. Her past medical history is significant for a seizure disorder. She has been taking phenytoin regularly and had no seizure episodes during the pregnancy. She admits to eating poorly and occasionally drinking alcohol during the first trimester. She lives with her boyfriend who abuses her physically. She recalls several episodes of abuse during the pregnancy. Which of the following is most likely responsible for fetal abnormalities?

81) A newborn infant has respiratory distress and trouble feeding in the nursery. The mother has no significant medical history, but the pregnancy was complicated by decreased fetal movement. On physical examination, you note that aside from shallow respirations and some twitching of the fingers and toes, the infant is not moving, and is very hypotonic. In the mouth there is pooled saliva and you note tongue fasciculations. Deep tendon reflexes are absent. Spinal fluid is normal. Appropriate statements about this condition include which of the following statements?

82) A 2-week-old infant presents with hepatosplenomegaly and a thick, purulent, bloody nasal discharge. Coppery, oval, maculopapular skin lesions are present in an acral distribution. The neurologic examination is normal, including head circumference. Which of the following is the most likely cause of this congenital infection?

83) A previously healthy 4-year-old child is brought to the physician for a school physical for kindergarten. His mother has brought in his immunization record and reports that received all his immunizations prior to age 2. He has received only a yearly influenza vaccine since age 2. His physical examination is unremarkable. Which of the following immunizations should he be given during this visit?

84) A 2-year-old boy is being followed for congenital cytomegalovirus (CMV) infection. He is deaf and developmentally delayed. The child’s mother informs you that she has just become pregnant and is concerned that the new baby will be infected and may develop serious consequences. Which of the following is true?

85) A 15-year-old female presents to your office with secondary amenorrhea. As part of your evaluation, you find that she is pregnant. After informing her of the pregnancy, you continue to explain that young mothers have a higher risk of several pregnancy-related complications, including which of the following?

86) A 16-year-old boy who is the backup quarterback for the local high school team is in your office complaining of worsening acne. For the last few months he has noted more acne and more oily hair. On his examination, you note gynecomastia and small testicular volume. He is SMR 5. Which of the following drugs of abuse is the likely explanation for all of his findings?

87) A 41-year-old woman who is 32-weeks pregnant presents to the emergency department in labor. Her pregnancy has been complicated by gestational hypertension. Her medical history is otherwise unremarkable. She does not abuse alcohol, tobacco, or illicit drugs. Despite medical interventions, her preterm labor cannot be arrested, and she delivers a 2 kg (41b, 5oz) female infant. Both she and the child do well after delivery. Which of the following is true regarding immunizations for this infant?

88) An adolescent with type 1 diabetes returns for a follow-up visit after his annual checkup last week. You note that his serum glucose is elevated, and his glycosylated hemoglobin (hemoglobin A1C) is 16.7%. This finding suggests poor control of his diabetes over at least which of the following time periods?

89) As part of your anticipatory guidance to new parents of a healthy new-born, you suggest putting the child in which of the following positions for sleep?

90) A 16-year-old Caucasian male presents to the office with pain and limited motion of the right knee. His right knee, as well as his right ankle, has swelled several times before. He has a history of easy bruising since childhood, and an episode of excessive bleeding after a tooth extraction. His uncle had similar problems. Which of the following is the most likely cause of this patient's joint pain?

91) A mother brings her daughter into the clinic for a routine health-care visit. On examination, you note that she walks alone, knows two words, throws objects, and comes when called. What is the most likely age of this infant?

92) Approximately 19 days after having had a severe sore throat, a 10-year-old girl is taken to a pediatrician because she is complaining that her arms and legs hurt. The mother reports that before the extremity pain began, the child had a rash with irregular boundaries that lasted about a day. Physical examination demonstrates mild fever, as well as swelling and erythema around several large joints. Laboratory studies show an elevated erythrocyte sedimentation rate, and ECG demonstrates a prolonged PR interval. Which of the following is the most likely explanation for these findings?

93) At birth, an infant is noted to have an abnormal neurologic examination. Over the next few weeks he develops severe progressive central nervous system (CNS) degeneration, an enlarged liver and spleen, macroglossia, coarse facial features, and a cherry-red spot in the eye. Which of the following laboratory findings most likely explains this child’s problem?

94) The parents of a 2-year-old bring her to the emergency center after she had a seizure. Although the parents report she was in a good state of health, the vital signs in the emergency center reveal a temperature of 39C (102.2F). She is now running around the room. Which part of the story would suggest the best outcome in this condition?

95) A 2-year-old child is brought to the emergency department with sudden onset of unresponsiveness, miosis, bradycardia, and muscle fasciculations. These findings are most suggestive of poisoning with which of the following?

96) A 2-year-old girl presents with fever of 39.3 C and irritability. She has had an upper respiratory tract infection for 4 days. On examination, the right ear is bulging and has poor movement on insufflation. Which of the following organisms is most likely responsible for these findings?

97) A 16-year-old girl presents with a history of primary amenorrhea. On examination, short stature and a short neck with a low posterior hairline are noted. Chromosomal analysis most likely would reveal which of the following?

98) During the examination of a 2-month-old infant, you note that the infant’s umbilical cord is still firmly attached. This finding prompts you to suspect which of the following?

99) A 2-week-old neonate is brought to the office due to poor feeding and persistent vomiting. He had an episode of jerky movements of his limbs this morning. He was delivered at term with no complications and weighed 2.7kg (6 Ib) at birth. He appears lethargic, irritable and jaundiced. On examination, he weighs 2.2kg (5 Ib). His liver and spleen are enlarged. Bilateral cataracts are evident. Which of the following is most consistent with these findings?

100) A 1-day-old infant appears dusky in the newborn nursery during feeding. Oxygen is immediately administered by nasal cannula. Shortly afterward, she develops tachypnea. On physical examination, her blood pressure from the right upper arm is 50/30 mm Hg, her pulse is 180/min, and her respirations are 60/min. An echocardiogram is consistent with hypoplastic left heart syndrome. Which of the following would likely be found on auscultation?

101) A previously healthy 5-year-old girl is brought to the emergency room from a camping trip because her parents are concerned about rabies. This morning, they found a bat in the child's tent. There were no obvious bite marks on the child. Afterwards, the girl helped her father clean animals he had brought back from a hunt, including squirrels, rabbits, and chipmunks. Later, while packing up the campsite, the child was bitten on the arm by a rat. Her encounter with which of the following animals most warrants post-exposure rabies prophylaxis?

102) A 4-week-old boy is brought to clinic by his mother because of a 1 day history of labored breathing. His birth was uneventful and immunizations have been up to date. His mother reports that the patient developed conjunctivitis on the fourth day of life. On physical examination, he is breathing rapidly at 40 breaths per minute and is afebrile. His chest reveals bilateral inspiratory crackles and a slight wheeze. On chest x-ray, bilateral pneumonia is evident. The leukocyte count is elevated at 15,000 with 40% eosinophils. Which of the following is the most likely pathogen causing the patient's symptoms?

103) 6-month-old male is brought to the office due to fussiness and tugging at his right ear for the past 2 days. He has had a fever of 39.4° C (103° F) for the past 2 days. His past medical history is significant for recurrent ear and lung infections, oral candidiasis, and persistent diarrhea by rotavirus. His temperature is 39.4° C (103° F), pulse rate is 150/min, respirations are 28/min, and blood pressure is 80/60mm Hg. Physical examination reveals an erythematous, bulging right tympanic membrane with poor mobility on pneumatic otoscopy. His lymph nodes are not palpable, and his tonsils are not visualized. His B and T lymphocyte levels are markedly reduced. The chest x-ray reveals an absent thymic shadow. What is the most likely etiology of this patient's condition?

104) A 6-year-old boy had been in his normal state of good health until a few hours prior to presentation to the ER room. His mother reports that he began to have difficulty walking, and she noticed that he was falling and unable to maintain his balance. Which of the following is the most likely cause for his condition?

105) A 9-year-old child has developed headaches that are more frequent in the morning and are followed by vomiting. Over the previous few months, his family has noted a change in his behavior (generally more irritable than usual) and his school performance has begun to drop. Imaging of this child is most likely to reveal a lesion in which of the following regions?

106) A 2-year-old boy is rushed to the emergency department by his 21 -year-old white mother because he had a sudden-onset nosebleed which has now subsided. He never had any previous episodes. He is "sickly" and suffers from a productive cough and diarrhea that "refuses to go." His stools are greasy and foul-smelling. His appetite is normal, although his diet consists mainly of milk. His mother's boyfriend lives with them and is a chronic alcoholic. He was delivered vaginally without any complications. His weight is at the 25th percentile for his age. Physical examination reveals dry skin and dried blood at the nasal turbinates. What is the most likely cause of this child's failure to thrive?

107) An 18-month-old male infant is brought to the office by his parents for a follow-up visit. He has a congenital condition that started at the age of 6 months with repeated vomiting and hypotonia, and progressively evolved into choreoathetosis, spasticity and dystonia. Over the past month, he has started biting his hands and arms, pinching himself and banging his limbs against the wall. His family history is unremarkable. On examination, he has several scars, cuts and bruises over his arms and hands. His uric acid levels are elevated. What is the most likely deficient enzyme in this patient?

108) A 16-day-old infant presents with fever, irritability, poor feeding, and a bulging fontanelle. Spinal fluid demonstrates gram-positive cocci. Which of the following is the most likely diagnosis?

109) A 16-year-old boy presents to the emergency center with a 2-day history of an abscess with spreading cellulitis. While in the emergency center, he develops a high fever, hypotension, and vomiting with diarrhea. On examination you note a diffuse erythematous macular rash, injected conjunctiva and oral mucosa, and a strawberry tongue. He is not as alert as when he first arrived. This rapidly progressive symptom constellation is likely caused by which of the following disease processes?

110) An 18-month-old child presents to the emergency center having had a brief, generalized tonic-clonic seizure. He is now postictal and has a temperature of 40C (104F). During the lumbar puncture (which ultimately proves to be normal), he has a large, watery stool that has both blood and mucus in it. Which of the following is the most likely diagnosis in this patient?

112) The mother and father of a newborn come in for the 2-week check-up. The mother complains of “colic” and asks if she can switch to goat’s milk instead of breast milk. Which of the following should be your main concern about using goat’s milk instead of breast milk or cow’s milk?

115) A 4-day-old infant is brought to the physician for an outpatient follow-up visit. The mother's pregnancy and delivery were uncomplicated. The infant weighed 3.4kg (7 .5 lb) and was 19 in (48.2 cm) long at birth. He did well in the newborn nursery and was discharged from the hospital on day 2 of life. Today his mother reports that he is exclusively breastfed, and nurses for 10 minutes every 3 hours. He has 3-4 wet diapers a day, and has not had a bowel movement for two days. On examination, he weighs 2.95 kg (6.5 lb) and is 19 in (48.2 cm) long. He appears jaundiced on the face and chest. The remainder of the physical examination is unremarkable. Laboratory values are shown below. Total bilirubin 15 mg/dl, direct bilirubin 1 mg/dl, Infant's blood type O positive, Mother's blood type A positive. Which of the following is the most likely cause of this infant's hyperbilirubinemia?

116) A 10-year-old presents with 2 months history of heavy menstrual-like bleeding. Menarche occurred 6 months ago and this first menses consisted of spotting for 3-4 days without cramps. Subsequent periods were light in flow but lasted 6 to 8 days. Which of the following is the most likely cause of her bleeding?

117) A 25-year-old woman comes to your office for counseling. She says that her husband has cystic fibrosis, and that she has no family history of this disease. They are planning to have a child. She wonders what the probability is for their baby to have cystic fibrosis. Which of the following is your best response in this situation?

118) An awake, alert infant with a 2-day history of diarrhea presents with a depressed fontanelle, tachycardia, sunken eyes, and the loss of skin elasticity. Which of the following is the correct percentage of dehydration?

119) A newborn infant is brought to the nursery for evaluation after delivery. The mother reports that the pregnancy was uncomplicated, but she had only two prenatal visits. The infant was born via normal spontaneous vaginal delivery and required no resuscitation. The infant has hepatosplenomegaly on examination. While in the hospital, the infant requires treatment for anemia and hyperbilirubinemia. On subsequent examinations, the infant has clear rhinorrhea and ulcerative lesions on his feet. Which of the following congenital infections is most likely in this patient?

120) A 17 -year-old boy is brought to the emergency department by his father after the boy began threatening him at home. Over the last several months, the father reports, the boy has been increasingly abusive. He was recently involved in a fist fight at school. The boy states that there is nothing wrong. He is otherwise healthy. He denies alcohol use, but does admit to occasional marijuana use. On examination he has acne on his forehead and back and his hairline is receding. There is palpable tissue underneath his nipples bilaterally Heart and lung exams are normal. What substance is this boy most likely abusing?

121) A 16-year-old African American male with sickle cell anemia presents complaining of a 1-week history of exertional dyspnea, fatigue, and generalized weakness. He denies fevers, chills, night sweats, or cough. His only medication is oxycodone for chronic pain. On physical examination, he weighs 68 kg (150 lbs) and is 168cm (66 in) tall His temperature is 36.7C (98F), blood pressure is 120/70 mm Hg, pulse is 76/min, and respirations are 18/min. All organ systems appear normal Laboratory studies show: Hematocrit 20%, Mean corpuscular volume 110 fl, Reticulocyte count 1.0%. Which of the following is the most likely mechanism underlying these findings?

122) In the 2nd week of life, a previously healthy newborn develops diarrhea. The stools are watery and voluminous and continue even when the infant is fasting. Which of the following is the most likely pathogen?

123) A 17-year-old girl presents to the office with a 5-day history of a malodorous vaginal discharge. She is sexually active and uses condoms for sexual intercourse. On examination, a thin, white discharge is seen. A "fishy" odor is produced when KOH is added to the discharge. The vaginal fluid has a pH of 5. Which of the following is the most likely finding on a microscopic examination of the vaginal fluid?

124) A 20-month-old male is brought to ER with high fever, confusion and a skin rash suggestive of measles. He has a history of recurrent respiratory infections over the last 6 months. The patient's family has recently emigrated from a rural Russian province. Which of the following forms of vitamin supplementation should be considered in this patient?

125) A 3-year-old male is brought to the emergency department for evaluation of right neck swelling. His parents noticed a lump on his right neck yesterday, which has since increased in size and is now erythematous and tender. He has been previously healthy except for mild upper respiratory tract symptoms last week. His temperature is 38C (100.4F), pulse is 90/min, and respiratory rate is 25/min. On examination, he is nontoxic appearing. A 5-cm anterior cervical lymph node is palpated on the right side. It is poorly mobile, warm, erythematous, and tender to palpation. There is no fluctuance or induration. What is the most likely organism causing these symptoms?

126) A 5-month-old infant is brought to the office for the evaluation of persistent vomiting, failure to thrive, and developmental delay. His antenatal and postnatal histories are not known to his Caucasian foster parents, who adopted him when he was 4 months old. The physical examination reveals an infant with blonde hair, fair skin and blue eyes. His urine has a peculiar musty odor. His plasma phenylalanine level is 40 mg/dl and tyrosine level is normal. His urinary phenylpyruvic and a-hydroxy phenylacetic acid levels are both increased. What is the most likely etiology of this child's symptoms?

127) A 2 1/2-year-old child is evaluated by a neurologist because of difficulty walking. Neurological examination documents ataxia and mental retardation. The neurologist notes the presence of multiple telangiectasias involving the conjunctiva, ears, and antecubital fossae. The child also has a history of multiple respiratory tract infections. Immunoglobulin studies on the child would most likely demonstrate an absence of which of the following?

128) A premature neonate with respiratory distress syndrome is maintained on mechanical ventilation in a neonatal intensive care unit. Two weeks after delivery, the nurses in the intensive care unit notice that higher ventilation settings are needed and that more secretions are being suctioned from the endotracheal tube. A chest x-ray film shows questionable new infiltrates. Which of the following is the most likely pathogen?

129) A 3-year-old boy is brought by his father to the Emergency Department with fever, headache and neck pain that developed over the past several hours. The father states he is not the birth father, and that he and his wife adopted the boy at 18 months of age after his birth mother abandoned him. Physical examination reveals a lethargic male with a temperature of 39.7 C (103.5 F). There is photophobia, and mildly injected conjunctiva are appreciated. Pupils are equal and reactive and funduscopic examination is unremarkable. The patient has neck stiffness with a positive Kernig's sign. A complete blood count reveals a leukocyte count of 24,000/mm3 with 64 segmented neutrophils and 25 bands. A lumbar puncture is performed that reveals elevated CSF pressure, decreased glucose, and elevated protein. A Gram's stain shows gram-negative pleomorphic rods. There is no growth on blood agar. Growth on chocolate agar reveals white colonies. Which of the following is the most likely pathogen?

130) A 2-week-old boy in the neonatal intensive care unit had a birth weight of 1200 g. Ultrasound of the head reveals grade II intraventricular hemorrhage and periventricular leukomalacia. An ophthalmologic examination reveals retinopathy of prematurity of both eyes. In addition, a hearing screen demonstrates bilateral hearing deficits. Which of the following is the most important determinant of this child's neurodevelopmental outcome?

131) A 9-year-old boy is brought to the pediatric clinic by his mother, who noticed that the left side of his mouth has started to droop over the past several days. In addition, he is unable to close his left eye completely and complains of it burning. Review of systems reveals a cold approximately two weeks ago and recent decreased taste sensation. Physical examination reveals a well-nourished male with normal vital signs. There is left eye ptosis and mild erythema of the left conjunctiva. His smile is asymmetrical on the left. Laboratory evaluation, including a complete blood count and chemistry profile, are normal. Which of the following infections is most closely associated with this patient's condition?

132) A 6-week-old child arrives with a complaint of “breathing fast” and a cough. On examination you note the child to have no temperature elevation, a respiratory rate of 65 breaths per minute, and her oxygen saturation to be 94%. Physical examination also is significant for rales and rhonchi. The past medical history for the child is positive for an eye discharge at 3 weeks of age, which was treated with a topical antibiotic drug. Which of the following organisms is the most likely cause of this child’s condition?

133) A 12-year-old girl comes to the physician for an annual examination. She has been in good health for the past year and has no complaints. She began having menses this year and, after a few irregular cycles, is now having a monthly period. Past medical history is significant for multiple episodes of otitis media as a child. Past surgical history is unremarkable. She takes no medications and has no known drug allergies. Physical examination is unremarkable. If not currently immune, which of the following immunizations should this patient most likely receive?

134) An infant is brought to the office for health maintenance visit. On examination, the infant turns when her name is called. She is able to say "mama." Her mother mentions that she also says "dada" at home. She is able to look for her mother when she gets frightened. She also waves bye-bye to the doctor when the doctor steps out of the examination room. What age of this child is most consistent with these developmental milestones?

135) A 4-year-old male is brought to the physician with fever and headache. His symptoms began two days ago with low-grade fever, cough, and congestion. Last night, he developed a temperature of 102 F (38.9 C) and became fussy and less active. Today, he is crying and complaining of a headache. His parents report that he has vomited twice today. In the office, his temperature is 102.5 F (39 C), pulse is 110/min, and respiratory rate is 20/min. On examination, he is irritable and shows signs of photophobia. His oropharynx is erythematous. Nuchal rigidity is present and when the neck is flexed, the patient flexes his lower extremities. The remainder of the physical examination is normal. Lumbar puncture is performed and the results are shown below. CSF: Glucose 60 mg/dL, Protein 80 mg/dL, RBC 10/mm3, WBC 100/mm3, Neutrophils 10%, Lymphocytes 70%, Monocytes 20%, Gram stain negative. Which of the following organisms is most likely responsible for this patient's presentation?

136) A 12-year-old boy is brought to the emergency department with a temperature of 39.1 C (102.4 F) at home, difficulty speaking, and odynophagia for 2 days, Physical examination reveals marked erythema of the right tonsil pillar and edema of the uvula with deviation to the left. In addition to anaerobic bacteria, which of the following organisms is most likely to be isolated from a tonsillar pillar aspirate?

137) A neonate is noted to have many abnormalities, a number of which are located in the midline. The infant has cleft lip and cleft palate. His eyes are very small and have fissures of the iris, shallow supraorbital ridges, and slanted palpebral fissures. He is deaf, and the ears are low set and malformed. Each hand has six fingers and a simian crease. Which of the following congenital abnormalities of the brain is particularly likely to be present in this infant?