Allergy & Immunology
Which of the following is true about IgA?
IgA provides defense against local infections in the respiratory, gastrointestinal, and genitourinary system.
A 16-year-old weightlifter presents with the complaint of chest pain along the right lower and midsternal border. He had just started a weightlifting program at school when he began to notice the chest wall discomfort after his third session. The pain is somewhat sharp and constant. It occurs mostly at rest. It increases some with inspiration. The pain does not radiate, and he has no other complaints. He is in no distress and his vital signs are completely normal. Examination of the heart reveals normal S1 and S2. No murmurs or rubs are heard. The lungs are clear. The abdomen is soft and benign.
Which of the following will most likely result in a diagnosis?
Palpation of the costochondral junctions
A febrile 17-year-old girl with a history of vomiting, diarrhea, myalgia, and altered mental status is admitted to the intensive care unit for what is believed to be toxic shock syndrome (TSS).
Which of the following best describes a common characteristic of the rash associated with the acute phase of this illness?
Diffuse macular erythroderma
A full-term female is born after a normal prenatal course to a 42-year-old G2P2 mother. After 24 hours, the infant appears very fussy, has a distended abdomen, and has not passed her meconium. Physical examination reveals a child with upward-slanting palpebral fissures, epicanthal folds, and generalized hypotonia.
Which of the following is the most likely diagnosis?
Hirschsprung disease
The parents of a 16-year-old boy present with multiple concerns about the behavior of their son. They are fearful that he is "using drugs." They describe him as apathetic and uninterested in school, and in the extracurricular activities he once enjoyed. Although often lethargic with little to no apparent energy, he becomes easily frustrated and angry, often lashing out at his parents over "minuscule things like being asked to take out the trash." His academic performance has declined, along with his overall appearance and dress. He has several "new friends," whom he refuses to introduce to his parents.
Which of the following substances is most likely to be detected on a urine drug screen in this patient?
Tetrahydrocannabinol (THC)
You are paged by the newborn nursery to evaluate a 2-day-old infant in respiratory distress. Physical examination is remarkable for cyanosis, nasal flaring, retractions, and a prominent heart murmur. A chest radiograph shows a boot-shaped heart and absent thymic shadow. While awaiting an echocardiogram, the infant develops severe hypocalcemic seizures.
What is the most likely diagnosis?
22q11.2 deletion syndrome
A 17-year-old patient is hospitalized with new-onset heart failure. He presents with hepatomegaly, bilateral pitting edema of lower extremities, and shortness of breath. He has a negative prior medical history except for a viral URI 10 days ago. Physical exam, CXR, and ECG findings are nonspecific. Endocardial biopsy is performed, which shows inflammatory infiltrates.
What is the most likely underlying cause of this patient's heart failure?
Myocarditis
An 18-year-old college freshman requests a prescription for malaria prophylaxis. She is traveling to an area in Africa where malaria is known to be resistant to chloroquine.
Which of the following antimicrobials is an appropriate alternative prophylactic medication for this patient?
Doxycycline
A 15-year-old boy presents as a new patient in your office. His mother reports that her son has always had developmental delays, poor eye contact, decreased social interests, and hand flapping. He has been diagnosed with low tone, as well as joint laxity. Physical examination reveals macrocephaly with large protuberant ears and a long face with a prominent jaw.
What additional clinical finding is most likely?
Macroorchidism
The mother of 2 children, 7 and 10 years of age, approaches you before their well-child exam due to behavior concerns. She and her husband divorced 2 months ago. Since the divorce, her 10-year-old daughter has had difficulty sleeping and a poor appetite. Her son has complained of almost daily headaches (that are mild and do not prevent activity) or belly pain and has had a decline in school performance.
In addition to examining each of the children and investigating for other pathologies, which of the following is the most appropriate advice?
Refer the children to a psychologist.
A 15-year-old girl presents with a 2- to 3-week history of diarrhea and abdominal pain. Several Giardia trophozoites with easily identified flagella are noted on stool microscopy.
Which of the following is known to increase the risk of giardiasis?
Selective immunoglobulin A deficiency
An electrocardiogram (ECG) demonstrates an upright T wave in V1.
For which of the following is this ECG finding abnormal?
A 3-year-old
A 2-year-old in day care presents for evaluation. Today, her mother learned that a case of meningococcal meningitis has occurred in one of the adults working at the care center. None of the children are ill, and none of the other adults working at the center are ill.
Which of the following do you recommend?
Your patient and all children (as well as adult workers) who have had close contact with the infected index case should be prophylaxed with appropriate antibiotics.
Soon after birth, a term male is noted to have noisy respirations that appear to be due, at least in part, to choanal stenosis, documented by difficulty passing a small feeding tube through either nares. He is also noted to have symmetrical midface hypoplasia caused by bony deficiency of the lateral portion of the orbital bones and bilateral zygoma and maxillary hypoplasia. Associated findings include a cleft palate, hypoplasia of the lower eyelids associated with absent lower eyelashes, and micrognathia.
Which of the following complications is most likely to occur?
Conductive hearing loss
A 15-year-old boy presents for a well-child exam. His mother recently read that suicide is one of the leading causes of death in adolescents; she is concerned about her son's mental health and reports that she has a history of depression. The patient reports some mild fatigue. He shares that his grades have not been as high as they once were, but he is passing alli his courses. He is trying to cut down on junk food and is eating out less often; he currently weighs 170 lb and has lost 5 lb since last year's visit. He reports difficulty falling asleep at night and often falls asleep 2-3 hours before his alarm wakes him. His mother reports that he has been less outgoing for the past few months. You conduct a more in-depth evaluation for depression.
Which of the following characteristics place this patient at high risk for the condition currently being evaluated?
Maternal history of depression
A 12-year-old girl requires a blood transfusion after sustaining major trauma in a motor vehicle accident. A few minutes into receiving the blood transfusion, she develops generalized hives, angioedema, and shortness of breath.
Which of the following congenital immunodeficiencies would increase her risk of developing anaphylaxis after this treatment?
Selective immunoglobulin A deficiency
A 6-year-old girl presents for evaluation with her parents after the school nurse had observed their daughter from time to time "jerking her hands, feet, and neck-almost in a dance-like manner." On physical examination, she is afebrile with stable vital signs. She is irritable and uncharacteristically uncooperative. She exhibits generalized hypotonia and difficulty performing fine motor skills (eg., writing her name). She nearly falls during Romberg testing. She is unable to hold her hands straight above her head; instead, her arms and palms consistently turn outward
Which of the following organisms is the most likely cause of the neurologic findings in this patient?
Group A B-hemolytic Streptococcus
The parents of a 4-year-old boy are concerned -over the last several weeks their son has been limping, and now he complains of back pain. They deny that he has been febrile. There is no history of recent trauma, although he is described as "always on the go." On physical examination, his temperature is 38.1°C (100.6°F). He refuses to bend forward and is tender over L3 and L4. Loss of lumbar lordosis is also noted. A plain radiograph shows narrowing of the disc space between L3 and L4.
Which of the following is most likely to be identified during additional evaluation of this patient?
Erythrocyte sedimentation rate of 88 mm/hour
An 8-year-old boy with short stature is noted to have dysmorphic facial features, which include a triangular-shaped face with downslanting palpebral fissures, hypertelorism, and a short, webbed neck. Musculoskeletal findings include joint laxity and pectus deformity. The 15* heart sound is normal and followed by a systolic ejection click, which is louder on inspiration; a systolic ejection murmur is best heard at the 2nd left intercostal space.
Review of this patient's past medical history is most likely to reveal which of the following?
Bleeding diatheses
A 5-year-old boy is brought in by his new foster mother for a placement evaluation and exam. He was removed from his previous home due to concern for neglect and physical abuse The foster mother states he has become increasingly upset when they leave for school in the morning-refusing to get in the car to leave for school on some mornings. His teacher reports that he will cry at the door for over an hour after his foster mother leaves and has difficulty transitioning to school activities. His foster mother also states that he has begun having difficulties at bedtime, including leaving his room frequently and sneaking into her room at night and falling asleep on the floor next to her side of the bed. Otherwise, he play: happily with his foster siblings, tells stories, and reads with others.
What is the most appropriate counseling to provide this patient's foster mother?
Separation anxiety disorder can be improved with positive discipline strategies, teaching self-regulation skills, and therapy.
During evaluation of a 3-year-old boy with a history of recurrent infection, laboratory findings include an elevated serum IgE level of 10,000 IU/mL.
This patient is at greatest risk of having an infection caused by which of the following organisms?
Staphylococcus aureus
You are on duty in the emergency department when a group of 4 companions bring in their friend, a 16-year-old female. She has scars from acute and chronic intravenous drug use.
She is acutely ill with a temperature of 40 °C (104 °F), HR 130 bpm, and RR 18 breaths/minute. She is in apparent distress. Her systemic venous pressure is elevated, and the jugular venous pulse contour is dominated by large c-v waves that swell with each inspiration. Your auscultatory examination reveals a Grade 3/6 pansystolic murmur, which is heard best at the lower left sternal border and radiates to the lower right sternal border and which accentuates to Grade 4/6 intensity with inspiration. The liver seems to pulsate with each systole.
A chest x-ray reveals scattered focal, white, fluffy opacities.
Which of the following is the most likely heart abnormality?
Tricuspid regurgitation
A child has been admitted and intubated for epiglottitis. Cultures of both the epiglottis and blood were positive for Haemophilus influenzae Type b (Hib). A week later, a classmate of the intubated child is admitted with culture-confrmed Hib meningitis.
In which of the following contacts exposed to this child would you recommend chemoprophylaxis?
All attendees in preschool and child care centers with 2 cases of invasive Hib (in the past 60 days), where partially or unimmunized children are in attendance
During an evaluation following a 10-minute generalized tonic-clonic seizure, a 7-year-old boy is noted to have 9 café au lait macules over his anterior and posterior trunk. All lesions measure between 7 and 12 mm. He has no previous history of a seizure disorder.
Which of the following bony abnormalities is most likely to be identified upon continued evaluation?
Sphenoid dysplasia
A 17-year-old boy presents to your office with his mother due to recent changes in his behavior. His mother reports that during the past 5 weeks, he sleeps < 3 hours per night without feeling tired. His appetite has decreased, and he has lost 5lb. He speaks faster and much more than usual. He has been skipping class and not doing homework, focusing instead on his new idea to start his own construction company. He also got a traffic ticket for speeding and spent $2,000 on shoes and clothing using his mother's credit card. During the visit, the patient is very happy and does not understand why he is seeing a doctor, especially now when he feels so excited and happy about his life, which is in great contrast to his past. When he was in the 10th grade, he was treated for an episode of major depression. He denies any drug or alcohol use. He does not take any medications at this time. His vital signs and physical exam are unremarkable except for weight loss. His urine drug screen is negative.
Which of the following conditions is the most likely cause of this patient's symptoms?
Bipolar disorder