You see an 8-year-old boy in accident and emergency who fell off his bike 3 days ago and scraped his left calf. The cuts are now angry, red and painful. You note he is a big boy and plot his growth: his weight is on the 99th centile and height is on the 75th centile. You note mild gynaecomastia and stretch marks on his abdomen which are normal skin colour. His past medical history is unremarkable except for mild asthma. What is the most likely cause of his large size?

A 16-year-old boy is brought to the GP by his parents. They are concerned he is the shortest boy in his class. He is otherwise well. His height and weight are on the 9th centile. His father plots on the 75th centile and his mother on the 50th centile for adult height. On examination, his testicular volume is 8 mL, he has some fine pubic and axillary hair. The rest of the physical examination is normal. On further questioning you elicit from his father that he was a late bloomer and did not reach his full height until he was at university. What is the most likely cause of the boy's short stature?

An 8 year old known asthmatic is brought into accident and emergency by ambulance as a 'blue call'. He has been unwell with an upper respiratory tract infection for the past 2 days. For the past 24 hours his parents have given him 10 puffs of salbutamol every 4 hours, his last dose being 90 minutes ago. The ambulance staff have given him a nebulizer but he remains agitated with a heart rate of 155, respiratory rate of 44 and sub/intercostal recessions and on auscultation there is little air movement heard bilaterally. Saturations in air are 85 per cent. He is started on 'back to back' nebulizers with high flow oxygen. How severe is his asthma exacerbation and what other bedside test would support this?

A 6-year-old boy with a history of anaphylaxis to peanuts is brought in by ambulance unconscious. He was attending a children's birthday party. His mother says there was a bowl full of candy and he may have eaten a Snickers bar but she is not sure and she did not have his EpiPen with her. His face and lips are swollen and erythematous, he is still breathing but weakly and there is wheeze. His pulse is tachycardic and thready. Which type of shock is this?

A newborn baby is born to non-consanguineous parents. She is noted to have puffy feet on her 1st day check. She weighs 2.0 kg with widely spaced nipples and absent femoral pulses. You have asked your registrar to review her as you think she may have Turner's syndrome. She agrees and asks you to send blood tests for karyotyping. Which is the chromosomal diagnosis of Turner's syndrome?

A baby is born and you are asked to do the baby check at 6 hours post-natal age. You go to see the baby and mum states that he has not yet had a feed. You advise they stay in hospital until the feeding is established. This is the first child of non-consanguineous parents. On day 4 when you review the baby he has still not had an adequate intake, has lost over 10 per cent in birth weight and is markedly hypotonic. Your consultant asks you to request genetic testing for Prader- Will syndrome. What is the inheritance of Prader-Willi syndrome?

An infant is delivered by cesarean section at 34 weeks' gestation because of preterm labor. There is no history of ruptured membranes, maternal fever, or abnormalities in fetal heart rate monitoring. The infant requires assisted ventilation with a bag-mask device and 100% oxygen in the delivery room. His Apgar scores are 5 and 7 at 1 and 5 minutes, respectively. An umbilical cord arterial pH is 7.23 and base deficit is 3 mmol/L. He is admitted to the newborn nursery, but transferred to the neonatal intensive care unit (NICU) within 1 hour for respiratory distress manifested by tachypnea and grunting. His arterial blood gas results (obtained on room air) upon admission to the NICU are: pH, 7.20; Pco2, 70 mm Hg; Po2, SO mm Hg, and base deficit 10 mmol/L. Of the following, the MOST common cause for this infant's respiratory distress is

A 12-year-old child who recently emigrated from southeast Asia has beta-thalassemia for which she has required frequent transfusions. She presents today with polyuria and polydipsia. On your initial evaluation, you detect a grade II/VI systolic murmur with a gallop rhythm, palpate the liver 4 em below the costal margin, and determine that the girl is well below the 5th percentile for height. Of the following, the MOST likely diagnosis is

A 2-year-old girl is rushed by ambulance to the emergency department for sudden-onset ataxia. Her parents have yet to arrive. On physical examination, the girl is afebrile, yet diaphoretic, with some nystagmus on far lateral gaze. Her ataxia has resolved. The remainder of physical examination findings are normal. Of the following, the MOST likely diagnosis for this child is

You are examining a 2-day-old term newborn prior to discharge. On physical examination, you note a 5 x 5 em mass in the right abdomen. The remainder of her physical examination findings are normal. Of the following, the MOST likely diagnosis is

An 18-year-old pregnant girl presents to your clinic with complaints of discomfort in her knees and hands. She denies any swelling or erythema of these areas or recent trauma. She takes no regular medications, and she has been healthy until 6 days ago, when she developed these complaints. She did receive a rubella vaccination about 1 month ago because on her first visit to an obstetrician she was found to have a negative serum titer to rubella. Her physical examination findings are normal. Of the following, the MOST likely diagnosis is

A 12-month-old boy presents for evaluation of severe eczema. His parents state that their son's eczema started soon after birth and has not responded to topical corticosteroids. The parents also are concerned that the infant has had frequent otitis media, sinus infections, and one episode of Streptococcus pneumoniae pneumonia requiring hospitalization last month. During your review of the laboratory studies performed, you notice that the infant has thrombocytopenia (20x103/mcL [20x109/L]) and small platelets. Of the following, the MOST likely diagnosis for this infant is

A 2-year-old girl presents for evaluation of fussiness, low-grade fever, and what her parents describe as "growing pains." On physical examination, you palpate a non tender mass deep in the right periumbilical area and note mild purple discoloration of the eyelids. Of the following, the MOST likely diagnosis is

A 12-year-old basketball player has complained of right knee pain immediately after games for 2 weeks. Although he had complained of knee pain intermittently earlier in the season, there is no history of swelling or injury of the knee. Physical examination findings of the knee are remarkable for full range of motion no effusion, and swelling over the proximal right tibia that is tender to palpation. Of the following, the MOST likely diagnosis is

You see a 7-day-old baby boy the day that his newborn screening test is reported to show a low thyroxine concentration of 7.8 mcgldL (100.4 nmol/L) and a thyroid-stimulating hormone concentration of 25 mcU/mL. The baby had a birth weight of 3,000 g and now weighs 3,100 g and is 48.3 em long. He looks healthy, and the thyroid is not palpable. The mother reports that she isbreastfeeding, and the baby seems to be feeding well. He is her first child. The mother tells you that she takes thyroid hormone for an underactive thyroid and has needed to take calcium and vitamin D since she was a small child "to keep her calcium up." You look at her more closely and realize that she is plump, quite short (perhaps 4 ft 10 in), has a round face, and has short stubby fmgers. She says that her mother also had short stature and similar problems. She has one brother who has similar problems and a sister who is 5 ft 6 in and does not have a problem with her calcium. Of the following, this baby and his mother MOST likely have

A 10-year-old child recently had cognitive testing that showed a full scale intelligence quotient of 105. On achievement testing, he performed at the 3rd percentile in reading and at the 50th percentile in math. Of the following, these findings MOST likely represent

An 11-year-old Caucasian boy who has no significant past medical history presents to the emergency department with a 3-day history of brown urine. He reports no dysuria, urgency, frequency, or abdominal or flank pain. His vital signs reveal: temperature, 99°F (37.2°C); blood pressure, 141/84 mm Hg; heart rate, 92 beats/min; and respiratory rate, 24 breaths/min. Significant findings on physical examination include moderate periorbital and leg edema. His urinalysis reveals moderate blood and 4+ protein. The serum complement 3 (C3) and C4 concentrations are both low. Of the following, the MOST likely cause of his hematuria is

A 16-year-old boy presents with a very swollen, painful right knee. He is a soccer player, but there is no history of recent injury. During the interview, you notice the boy has injected conjunctivae. Of the following, further evaluation MOST likely will reveal

You diagnose attention-deficit/hyperactivity disorder in a 10-year-old boy and recommend treatment with methylphenidate. His mother asks about potential adverse effects of the treatment. Of the following, the MOST common adverse effect of treatment is

You are asked to evaluate a 15 year-old boy who presented to the emergency department with gross hematuria that began the day before. He ran his first marathon yesterday. He reports no dysuria, urgency, frequency, or abdominal or flank pain. His vital signs and physical examination findings are normal. Urinalysis reveals: specific gravity, 1.010; pH, 6.0; large blood; no protein; 0 to 2 red blood cells; and 0 to 2 white blood cells. A serum creatinine is 2.7 mgldL (238.7 mcmoi!L). His complete blood count is normal. Of the following, the MOST likely cause of his hematuria and renal failure is

The mother of a 4-year-old otherwise healthy-appearing boy brings him in for evaluation because he had profound generalized body odor (bromhidrosis) for the past several days. Upon careful questioning, the mother recalls an episode of sneezing followed by a 3- to 4-day history of a purulent, blood-tinged nasal discharge. Of the following, the most likely cause of the body odor is

A newborn has microcephaly, dysmorphic features (including a prominent forehead, protuberant ears, and micrognathia), bilateral hip dislocation, clinodactyly, and a single transverse palmar crease bilaterally. Peripheral blood chromosome analysis reveals an unbalanced translocation that results in partial trisomy 9. Of the following, the MOST appropriate statement to include when discussing the diagnosis with the parents of this infant is that

You are asked to see a 14-year-old girl who developed pubic hair at age 11 years and breast buds at age 12 years, but has not reached menarche. She is a gymnast who practices 2 hours a day. Breast tissue is Sexual Maturity Rating (SMR) 2 and pubic hair is SMR 4. She is 57 in tall and weighs 86 lb. The results of gonadotropin laboratory studies are a luteinizing hormone concentration of 18 miU/mL (18 lUlL) (normal adult female, 2 to 70 miU/mL [2 to 70 lUlL]) and a follicle-stimulating hormone concentration of 40 miU/mL (40 lUlL) (normal adult female, 1 to 30 miU/mL [1 to 30 lUlL]). Of the following, the MOST likely cause of the primary amenorrhea in this patient is

You are seeing a newborn boy for the first time. Several prenatal ultrasonographic examinations revealed bilateral hydronephrosis. The boy's weight and height are appropriate for gestation, and his physical examination findings are unremarkable. Postnatal ultrasonography reveals severe bilateral hydronephrosis. Of the following, the MOST likely cause of the hydronephrosis is

Over the past week, you and your colleagues have seen a number of previously healthy children younger than 2 years of age who present with fever, coryza, cough, vomiting, and diarrhea. Several of the children have required hospitalization for respiratory distress and pneumonia. You suspect that influenza virus infection is the cause of these illnesses. Of the following, the MOST rapid test to confirm the diagnosis in these patients is

A 4-year-old boy presents with a history of chronic upper and lower respiratory tract infections. His weight is 15 kg (25th percentile), height is 97 em (lOth percentile), temperature is 98.1 °F (36.8°C), and pulse oximetry is 96% on room air. On physical examination, he coughs intermittently and has mild clubbing. On nasal examination, you note purulent rhinorrhea and nasal polyps (Item Q143A). Auscultation of the heart reveals a regular rate and rhythm, with the point of maximal impulse displaced to the right. Of the following, the MOST likely diagnosis is

A 12-year-old child is struck in the right eye by a baseball. He now complains of double vision when he looks to the left. On physical examination, you note marked swelling and bruising circumferentiaUy around the boy's right eye. His pupillary reflexes are normal, he has no blood in the anterior chamber of the eye, and his optic disc margins are sharp. He has dysconjugate gaze to the left but not to the right. His vision is 20/20 out of the left eye and 20/30 out of the right eye. Other findings on his neurologic examination are normal. Of the following, the MOST likely diagnosis is

A 2-year-old boy who has been followed by your practice since birth presents for a health supervision visit. On careful physical examination, you have difficulty locating the right testis. In reviewing your records, you note that this is a new rmding. Of the following, the MOST likely diagnosis is

You are evaluating a newborn boy who has lax abdominal musculature and bilateral undescended testes. Other findings on physical examination are normal. Of the following, the MOST likely urologic abnormality in this boy is

A 7-year-old child presents with a scalp lesion characterized by patchy areas of hair loss with palpable suboccipital nodes. Of the following, the MOST likely diagnosis is

During the health supervision visit of a 2-year-old boy who is new to your practice, you note a productive cough that his mother says has been present for several months. His weight is below the 5th percentile. Fine crackles are present in his lungs bilaterally, and he has mild clubbing of the fingers. The remainder of his physical examination findings are unremarkable. A chest radiograph reveals poorly defined bronchovascular markings and a few cystic spaces bilateraUy, prompting you to order computed tomography scan of the chest, which reveals diffuse bronchiectasis. Of the following, the MOST likely diagnosis is

A child presents for her 2-week evaluation after being delivered by a midwife at home. The parents are concerned that they have never seen her turn her head, which makes it difficult for her to feed at the breast. They also note that her back does not appear normal. On physical examination, her hairline appears low posteriorly. You confirm that she does not turn her head, and when placed prone, does not turn her head to the side. Her right scapula appears to be higher than the left, and you note that the spine does not appear to be perfectly straight, suggesting congenital scoliosis. You obtain an anteroposterior radiograph of the cervical spine, which shows multilevel segmentation anomalies (Item Q165A) in the mid to lower cervical spine. Of the following, the condition that is MOST consistent with these findings is

A mother brings her 12-month-old boy to you because he holds his head tilted to the right. She tells you that he periodically draws up both his legs and cries. The child has developed normally, but does not yet walk or cruise. On physical examination, he has mildly increased deep tendon reflexes in the upper and lower extremities, but other findings are normal. Of the following, the study MOST likely to establish this boy's diagnosis is

You are evaluating a 10-year-old boy who has intermittent urinary incontinence. Voiding cystourethrography detects a urethral stricture. Of the following, the MOST likely cause of this boy's urethral stricture is

An infant is born following a pregnancy complicated by no prenatal care and reduced fundal height for gestation on examination during labor. Fetal heart rate tracings are nonreassuring. Physical examination of the infant reveals a birthweight of 1,800 g, flattened facies, low-set ears, respiratory distress, a large flank mass on the left, and joint contractures. Renal ultrasonography documents a single left multicystic and dysplastic kidney; the right kidney is absent. Of the following, the BEST explanation for these findings is

A father brings his 2-year-old daughter to you because he has noticed "funny eye movements" over the past 2 weeks. Upon physical examination, you find that the child has pendular nystagmus, her head is tilted to the right, and she nods her head. Other findings on the physical examination are normal. Of the following, the MOST likely diagnosis is

A 15-year-old agitated and delusional boy presents to the emergency department. Physical examination reveals tachycardia, sweating, and pupils that are dilated and react slowly, but there is no nystagmus, and the eyelids and conjunctivae are normal. Of the following, the substance that MOST likely was abused by this boy is

The parents of an 8-year-old girl who has asthma would like to know more about possible triggers. The girl has had mild persistent asthma since age 5 years and frequently has increased symptoms in the fall that coincide with starting school. During the fall, she experiences increased rhinorrhea, sneezing, and ocular pruritus. These nasal and ocular symptoms have occurred each fall for the past 3 years but generally do not occur at other times of the year. Of the following, the MOST likely trigger for the patient's asthma exacerbations is

A 7-year-old girl is hospitalized after the acute onset of fever, rapid development of hypotension, diffuse erythema of the skin, rapidly accelerating renal failure, and multisystem organ involvement. Toxic shock syndrome (TSS) is diagnosed. Of the following, the MOST likely finding associated with TSS caused by toxin-producing Streptococcus pyogenes is

A 4-month-old is brought to clinic by his parents for evaluation of bilateral droopy eyes. His mother believes this has developed just over the last week. The child recently started taking cereal in addition to breastfeeding and has been constipated. Physical examination reveals droopy eyelids and 1 + deep tendon reflexes diffusely. Of the following, the MOST likely diagnosis is

You are evaluating a 2-year-old boy because he bangs his head on his bed before he goes to sleep. His mother has no other concerns about his behavior. There have been no recent changes in the family or stresses that she can identify. Physical examination findings are normal except for excoriated skin on the boy's forehead and minimal ecchymosis. Of the following, the MOST likely diagnosis is

A 10-year-old girl presents to the emergency department with a 1-day history of brown urine. She reports no dysuria, urgency, frequency, or abdominal or flank pain. Her vital signs include: temperature, 98.8°F (37.1 °C); blood pressure, 165/97 mm Hg; heart rate, 84 beats/min; and respiratory rate, 20 breaths/min. On physical examination, moderate periorbital edema is evident, but there are no other abnormalities. Urinalysis reveals moderate blood and 4+ protein. The serum complement 3 (C3) concentration is low, and the C4 concentration is normal. Of the following, the MOST likely cause of this girl's hematuria is

Several weeks ago, a boy presented with fever, malaise, headache, and a skin lesion. The lesion began as a red papule and slowly enlarged to form a large annular ring with a flat erythematous border. Today he complains of recurrent joint pains that are particularly severe in his knees. Of the following, the MOST Likely diagnosis is

An 18-month-old girl is brought to your clinic because her mother feels she is pale. She has no relevant findings on past medical history and eats a regular diet. She is alert and interactive but has significant pallor. The remainder of the physical examination results are normal. A complete blood count reveals a normal white blood cell count and platelet count. The hemoglobin concentration is 4.5 g/dL (45 giL) and mean cell volume is 74 fL. Of the following, the MOST likely diagnosis is

A newborn female has a cardiac murmur. Before the cardiologist arrives to evaluate her, she has a seizure. Results of laboratory testing include a serum calcium concentration of 5.0 mgldL (1.25 mmoUL). Subsequently, echocardiography reveals an aortic arch anomaly. Of the following, the MOST appropriate test to obtain to aid in the diagnosis of this infant is

A 15-year-old girl who is hirsute has had menses six times in the past year. She is overweight (body mass index of 35 kg!M2) and has a blood pressure of 110175 mm Hg. Her cholesterol concentration is 170 mg/dL (4.4 mmoUL), with a high-density lipoprotein cholesterol concentration of 55 mgldL (1.4 mmoUL) and fasting triglyceride value of 74 mgldL (0.84 mmoUL). Her fasting blood glucose value is 108 mgldL (6.0 mmoUL), and a 2-hour post-oral glucose blood glucose value is 115 mgldL (6.4 mmoUL). Of the following, the MOST likely diagnosis for this patient is

A 14-year-old boy presents to the emergency department with a 2-week history of bilateral leg edema and a 3-day history of abdominal swelling. His vital signs are: temperature, 98.4°F (36.9°C); blood pressure, 125/67 mm Hg; heart rate, 84 beats/min; and respiratory rate, 20 breaths/min. Physical examination shows moderate ascites and 2+ leg edema. His urinalysis reveals negative blood and 4+ protein. Serum complement concentrations are ordered and found to be normal. Of the following, the MOST likely cause of his edema and proteinuria is

An anxious 16-year-old girl presents to the emergency department complaining of a sudden onset of feeling that she is unable to breathe. She also complains of tingling around her lips and fingertips. Upon further questioning, you learn that she has had frequent similar episodes in the past. She has no history of asthma, and she has no chest pain or fever. Physical examination reveals a respiratory rate of 30 to 40 breaths/min, oxygen saturation on room air of 99%, no intercostal retractions, and no fever. No wheezing or crackles are evident on chest auscultation; breath sounds are good bilaterally. The balance of findings on the physical examination, including a complete neurologic evaluation, are normal. Of the following, the symptom that BEST distinguishes the correct diagnosis from compensatory hyperventilation is

You are seeing a 6-month-old boy for a health supervision visit. On physical examination, you note bilateral, non tender scrotal swelling. The scrotum transilluminates. The remainder of the physical examination findings are normal. Of the following, the MOST likely diagnosis is

A 12-year-old African-American girl presents to your office with a 2-day history of gross hematuria. She describes the urine as brown. She states that she has had an upper respiratory tract infection for about 3 days. She denies dysuria, urgency, or frequency. Her vital signs and physical examination findings are normal. Urinalysis reveals: specific gravity, 1.025; pH, 6.5; large blood; no protein; too numerous-to-count red blood cells; and 0 to 2 white blood cells. Serum electrolyte concentrations are normal. Of the following, the MOST likely cause of her gross hematuria is