USMLE Step 3 Quiz: Well Child And Adolescent Care

What this quiz covers

This quiz focuses on Well Child And Adolescent Care, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 3.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Initiate treatment with lisinopril for hypertension.
2. Order a full endocrine workup including thyroid studies and a cortisol level.
3. Recommend intensive lifestyle modification and schedule follow-up blood pressure checks. (correct answer)
4. Refer the patient for bariatric surgery evaluation.

Explanation: This patient has Class II obesity (BMI >120% of the 95th percentile) and Stage 2 hypertension (BP ≥95th percentile + 12 mm Hg or ≥140/90). The first-line treatment for obesity-related hypertension in adolescents is comprehensive lifestyle modification, including diet, physical activity, and behavior change. Antihypertensive medication is typically reserved for persistent hypertension after a trial of lifestyle changes, or for symptomatic or Stage 2 hypertension. However, lifestyle intervention is always the initial step. Follow-up BP checks are needed to confirm the diagnosis of sustained hypertension before starting medication. (A) Starting medication immediately is premature without first attempting lifestyle modification and confirming sustained hypertension over several visits. (B) Endocrine causes of obesity are rare. A workup is only indicated if there are specific signs, such as growth failure, which is not present here. (D) Bariatric surgery is an option for severe obesity but is considered only after failure of intensive lifestyle modification.

Question 2

1. Initiate a trial of oral desmopressin before bedtime.
2. Implement a daytime bladder training program with timed voiding.
3. Reassure the parents and recommend motivational therapy, such as a star chart. (correct answer)
4. Restrict the child's fluid intake after 2:00 PM.

Explanation: This child has primary monosymptomatic nocturnal enuresis, which is bedwetting in a child who has never achieved nighttime dryness and has no other lower urinary tract symptoms. In a 6-year-old, this is often a developmental issue. The first-line management is education, reassurance, and positive reinforcement (motivational therapy). The family should be counseled that it is common and not the child's fault. (A) Pharmacotherapy like desmopressin is considered a second-line treatment, typically reserved for older children (≥7 years) or when initial behavioral therapies fail and the enuresis is causing significant distress. (B) Bladder training is used for daytime incontinence or bladder overactivity, not isolated nocturnal enuresis. (D) While modest fluid restriction in the evening (1-2 hours before bed) is reasonable, severe restriction throughout the afternoon is unnecessary and can lead to dehydration.

Question 3

1. Check a complete blood count and ferritin level. (correct answer)
2. Switch the child to 2% milk to reduce caloric intake from milk.
3. Recommend an over-the-counter multivitamin without iron.
4. Reassure the parents that picky eating is a normal developmental phase.

Explanation: This child's history of excessive cow's milk intake (>24 ounces/day) and limited diet of iron-rich foods places her at high risk for iron deficiency anemia. Cow's milk is low in iron, and excessive intake can cause microscopic gastrointestinal bleeding and interfere with iron absorption. The clinical finding of pallor further raises suspicion. Therefore, the most appropriate next step is to screen for anemia with a complete blood count (which would show microcytic anemia) and to assess iron stores with a ferritin level. (B) Children between ages 1 and 2 should drink whole milk for adequate fat for brain development. The issue is the quantity of milk, not its fat content. (C) If the child is iron deficient, an iron supplement is needed, not a multivitamin without iron. (D) While picky eating can be normal, this child's specific dietary pattern has significant medical risks that should not be dismissed.

Question 4

1. Refer the patient directly to a pediatric orthopedic surgeon.
2. Reassure the family that this is a benign finding and re-screen in one year.
3. Order standing posteroanterior and lateral spine radiographs. (correct answer)
4. Initiate a physical therapy referral for core strengthening exercises.

Explanation: A scoliometer reading of 5 to 7 degrees is considered a positive screen and warrants further investigation. The appropriate next step is to obtain standing PA and lateral spine radiographs to confirm the presence of scoliosis and to measure the Cobb angle, which quantifies the curve's severity. Referral to orthopedics is indicated based on the results of the imaging (e.g., for a Cobb angle >20-25 degrees or if significant growth remains), not on the screening result alone. Reassurance is inappropriate for a positive screen, and physical therapy should not be initiated without a confirmed diagnosis and severity assessment.

Question 5

1. Explain that cereal in the bottle is a choking hazard and that infants this age do not need supplemental water. (correct answer)
2. Acknowledge his efforts and suggest limiting water to 2 ounces per day to prevent toxicity.
3. Endorse the use of rice cereal in the bottle as it is a common practice to improve infant sleep.
4. Advise that rice cereal is only for reflux and to switch from water to a pediatric electrolyte solution.

Explanation: This response correctly addresses two common and potentially harmful parenting misconceptions. First, adding cereal to a bottle is not recommended as it does not improve sleep, can lead to overfeeding, and poses a choking risk. Second, infants under 6 months of age receive all their hydration needs from breast milk or formula and should not be given supplemental water; doing so can lead to oral water intoxication and hyponatremia. The other options are incorrect as they either endorse a harmful practice or provide inappropriate alternative advice.

Question 6

1. Inform the patient that parental consent is required for contraceptive prescriptions for minors.
2. Encourage the patient to discuss her decision with her parents before providing a prescription.
3. Prescribe a suitable method of contraception without notifying her parents. (correct answer)
4. Schedule a joint meeting with the patient and her mother to facilitate communication.

Explanation: In most jurisdictions, minors have the legal right to consent to confidential reproductive health services, including contraception, without parental notification or consent. The physician's primary obligation is to the patient. Withholding contraception pending parental involvement creates a barrier to essential medical care and increases the risk of unintended pregnancy. While encouraging open communication with parents is often beneficial, it should not be a prerequisite for providing care, especially when the patient explicitly requests confidentiality.

Question 7

1. Refer for a formal hearing evaluation to rule out hearing impairment.
2. Administer a standardized autism-specific screening tool. (correct answer)
3. Reassure the parents that boys often exhibit delayed speech development.
4. Schedule a follow-up in 6 months to re-evaluate his language skills.

Explanation: The child exhibits multiple red flags for autism spectrum disorder (ASD), including impaired social communication (lack of pointing, poor eye contact), restricted interests, and repetitive behaviors (hand flapping, lining up toys). The American Academy of Pediatrics recommends universal ASD screening at 18 and 24 months. Given the specific concerns, the most appropriate next step is to use a validated, autism-specific screening tool like the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F). While hearing loss can cause speech delay, it does not explain the other signs. Reassurance or delaying evaluation is inappropriate given the number of concerning features.

Question 8

1. Acknowledge their concern, state that the recommended schedule is safe, and strongly recommend adhering to it. (correct answer)
2. Agree to their proposed alternative schedule to ensure the child receives at least some vaccines.
3. Inform them that the practice has a strict policy against deviating from the CDC schedule.
4. Provide them with informational pamphlets and defer the vaccination decision to the next visit.

Explanation: The most appropriate initial approach to vaccine hesitancy is to use a presumptive and patient-centered technique. This involves acknowledging the parents' concerns, validating their role in their child's health, directly addressing their specific misconception (the safety and efficacy of the recommended schedule), and providing a clear, strong recommendation. While agreeing to an alternative schedule may be a last resort to prevent complete refusal, it is not the best initial response as it prolongs the period of susceptibility to disease. A rigid policy may cause the family to leave the practice, and deferring the decision misses a crucial opportunity for education and timely protection.

Question 9

1. Admit the infant to the hospital for inpatient phototherapy.
2. Advise temporarily supplementing with formula to decrease enterohepatic circulation.
3. Reassure the mother, encourage continued frequent breastfeeding, and follow up in 24-48 hours. (correct answer)
4. Obtain a direct bilirubin, CBC, and reticulocyte count to evaluate for hemolysis.

Explanation: This infant's presentation is consistent with breastfeeding jaundice. The weight loss is within the acceptable limit (<10%), and the diaper output suggests adequate milk intake. The total bilirubin level of 14 mg/dL at 96 hours of age falls in the low-intermediate risk zone on the Bhutani nomogram and is well below the threshold for phototherapy. Further workup for pathologic jaundice is not indicated in the absence of risk factors or a rapidly rising bilirubin. The best management is to optimize breastfeeding, provide reassurance, and ensure close follow-up to monitor weight and bilirubin levels.

Question 10

1. Obtain a venous blood sample to confirm the lead level. (correct answer)
2. Refer the family to the local health department for a home environmental assessment.
3. Initiate oral chelation therapy with succimer.
4. Provide nutritional counseling and recheck a capillary sample in 3 months.

Explanation: Capillary blood lead samples have a high rate of false positives due to external contamination. Therefore, any elevated capillary lead level (≥3.5 µg/dL per 2021 CDC guidelines) must be confirmed with a venous blood draw. All other actions, such as public health referral, nutritional counseling, or consideration of chelation therapy (which is reserved for much higher levels, typically >45 µg/dL), should only be undertaken after the elevated level is confirmed via a venous sample.

Question 11

1. No lipid screening is necessary at this time.
2. Fasting lipid panel. (correct answer)
3. Hemoglobin A1c.
4. Non-fasting total cholesterol and HDL cholesterol.

Explanation: The American Academy of Pediatrics recommends universal lipid screening for all children between ages 9 and 11. In addition, they recommend selective screening for children with risk factors, such as a family history of premature cardiovascular disease (defined as <55 years in a male first-degree relative). This patient qualifies for screening on both counts. Because he has a specific high-risk family history, a fasting lipid panel is the preferred test to accurately measure LDL cholesterol and guide potential management. A non-fasting panel is an acceptable alternative for universal screening but is less ideal in high-risk scenarios. HbA1c is not indicated.

Question 12

1. Underlying celiac disease or other malabsorptive process.
2. Normal physiologic anorexia of toddlerhood.
3. Insufficient protein and fat intake in his diet.
4. Excessive milk intake causing early satiety. (correct answer)

Explanation: Excessive milk consumption is a common cause of poor appetite and inadequate intake of other foods in toddlers. Milk is low in iron and can cause early satiety, displacing more calorie- and nutrient-dense foods from the diet. The recommended daily milk intake for a toddler is 16-24 ounces. This child's intake of 32 ounces is likely filling him up, leading to refusal of other foods and subsequent poor weight gain. While physiologic anorexia is common, a drop of 25 percentile points on the growth chart is not normal. His diet is likely adequate in protein and fat, but lacks variety. Celiac disease is less likely than this very common nutritional issue.

Question 13

1. Attempt an automated photoscreening test in the office.
2. Refer the patient to a pediatric ophthalmologist. (correct answer)
3. Schedule a return visit in 3 months to reattempt the vision screen.
4. Reassure the parents that intermittent eye crossing is normal at this age.

Explanation: The detection of strabismus (misalignment of the eyes, in this case esotropia) on physical examination is an immediate indication for referral to a pediatric ophthalmologist. Strabismus can lead to amblyopia ('lazy eye'), a condition of reduced vision in one eye that can become permanent if not treated early. The positive finding on the cover-uncover test supersedes the need for or results of visual acuity screening. Delaying referral or providing reassurance is inappropriate as early intervention is critical to preserve vision. While intermittent strabismus can be normal in the first few months of life, it is abnormal in a 4-year-old.

Question 14

1. Prescribe a course of oral fluoride supplements for the child.
2. Recommend brushing the child's teeth with a non-fluoridated toothpaste.
3. Apply topical fluoride varnish in the office and refer to a dentist. (correct answer)
4. Advise switching the nighttime bottle content from milk to water.

Explanation: The physical examination findings are classic for early childhood caries (ECC), often called 'baby bottle tooth decay.' The patient requires prompt evaluation by a dentist. In the primary care setting, the application of topical fluoride varnish is a key evidence-based intervention to prevent and arrest the progression of caries. It is recommended for all children starting at tooth eruption. Oral fluoride supplements are only for children with fluoride-deficient water sources. Fluoridated toothpaste (rice-grain amount) is recommended. Simply switching to water is insufficient as it does not address the existing decay.

Question 15

1. Reassure the mother that a startle reflex indicates normal hearing.
2. Refer for a diagnostic audiological evaluation to be completed before 3 months of age. (correct answer)
3. Perform an office-based screening test with otoacoustic emissions today.
4. Re-evaluate at the 2-month visit and refer only if concerns persist.

Explanation: Any infant who does not pass the newborn hearing screen requires formal audiologic evaluation. The national goal is to follow the '1-3-6' rule: screen by 1 month, diagnose by 3 months, and enter intervention by 6 months. After a failed screen, the next step is a formal diagnostic evaluation (e.g., auditory brainstem response test), not just another screen. Parental observation and the startle reflex are unreliable indicators of hearing. Delaying referral would violate the standard of care and could lead to worse language and developmental outcomes if hearing loss is present.

Question 16

1. Advise starting an iron-fortified infant cereal and re-evaluate at the 12-month visit.
2. Obtain a complete blood count and serum ferritin level. (correct answer)
3. Recommend increasing supplementation with vitamin D drops to 800 IU daily.
4. Reassure the mother that pallor is a common finding in fair-skinned infants.

Explanation: This infant has multiple risk factors for iron deficiency anemia (exclusive breastfeeding beyond 6 months without iron supplementation) and clinical signs (pallor, decreased activity). Universal screening for anemia is recommended between 9 and 12 months, but this infant's symptoms warrant diagnostic testing with a complete blood count and ferritin level. Simply starting iron-fortified cereal without confirming the diagnosis is insufficient given the clinical signs. Vitamin D supplementation is important but does not address the concern for anemia. Reassurance is inappropriate as it dismisses clear signs of a potential medical problem.

Question 17

1. Admit to the hospital for intravenous fluid resuscitation with normal saline.
2. Prescribe an oral antiemetic and advise parents to give diluted juice at home.
3. Supervise a trial of an oral rehydration solution in the office. (correct answer)
4. Advise the mother to stop breastfeeding for 24 hours and offer soy formula.

Explanation: This infant has clinical signs consistent with mild dehydration (weight loss <5%, tacky mucous membranes, slightly increased heart rate, normal mental status). The initial treatment of choice for mild to moderate dehydration is oral rehydration therapy (ORT) with an oral rehydration solution (ORS). An in-office trial of ORT is appropriate to ensure the infant can tolerate the fluids without vomiting before being sent home with a detailed plan. IV fluids are reserved for severe dehydration or ORT failure. Diluted juice is hyperosmolar and can worsen diarrhea. Breastfeeding should be continued alongside ORT.

Question 18

1. Obtain a bone age radiograph of the left wrist.
2. Measure serum LH, FSH, and estradiol levels.
3. Refer to a pediatric endocrinologist for primary amenorrhea.
4. Reassure the mother and patient that this represents a normal progression of puberty. (correct answer)

Explanation: The normal sequence of female puberty is thelarche (breast budding), followed by pubarche (pubic hair development), a growth spurt, and finally menarche. Menarche typically occurs about 2 to 2.5 years after the onset of thelarche, usually during Tanner stage 3 or 4 of breast development. This patient, at Tanner stage 2, is at the beginning of her pubertal development. It is entirely normal that she has not yet reached menarche. Therefore, the most appropriate action is reassurance. A workup for delayed puberty or primary amenorrhea is not indicated at this time.

Question 19

1. Clear for full sports participation as flow murmurs are common in adolescents.
2. Obtain a chest radiograph and a complete blood count in the office.
3. Refer to cardiology for an electrocardiogram and echocardiogram. (correct answer)
4. Restrict from contact sports but allow participation in conditioning exercises.

Explanation: This patient has two major red flags for hypertrophic cardiomyopathy (HOCM): a family history of sudden death in a young relative and a dynamic murmur that increases with maneuvers that decrease preload (standing from a squat, Valsalva). HOCM is a leading cause of sudden cardiac death in young athletes. The patient must be restricted from sports participation pending further evaluation. The definitive next step is referral to a cardiologist for an ECG and echocardiogram. A chest x-ray is not the primary diagnostic tool. Reassurance is inappropriate given the concerning findings.

Question 20

1. Initiate treatment with a selective serotonin reuptake inhibitor.
2. Clear him for sports but strongly advise him to utilize school counseling services.
3. Immediately refer the patient to a child and adolescent psychiatrist.
4. Conduct a detailed clinical interview to assess for diagnostic criteria and acute safety risks. (correct answer)

Explanation: A positive screening test (a PHQ-9 score of ≥10 indicates at least moderate depression) requires a comprehensive clinical evaluation by the primary care physician. This includes a detailed interview to confirm the diagnosis of major depressive disorder according to DSM-5 criteria, assess for comorbidities, and perform a thorough safety assessment (including suicidality, self-harm, and access to means). Initiating medication or referring to psychiatry before conducting this assessment is premature. Clearing for sports without a full evaluation and plan is insufficient to address the patient's significant mental health needs.