USMLE Step 2 Quiz: Growth Development And Preventive Care

What this quiz covers

This quiz focuses on Growth Development And Preventive Care, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.

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. Reassurance and anticipatory guidance (correct answer)
2. Referral for physical therapy evaluation
3. MRI of the brain and spine
4. Serum creatine kinase level

Explanation: The patient is demonstrating age-appropriate developmental milestones. At 9 months, an infant should be able to sit unsupported, babble, and develop a pincer grasp, all of which this child is doing. Crawling is a variable milestone, with a wide range of normal onset; some healthy infants skip crawling altogether. The finding of rocking on hands and knees is a pre-crawling behavior, indicating that gross motor development is progressing normally. Therefore, the most appropriate next step is to reassure the mother and provide anticipatory guidance about the normal variability in achieving this milestone.

Question 2

1. Measles, mumps, and rubella (MMR)
2. Varicella
3. Inactivated poliovirus (IPV) (correct answer)
4. Hepatitis A

Explanation: The standard pediatric immunization schedule in the United States includes the second doses of several vaccines at the 4-month well-child visit. These include Diphtheria, tetanus, and acellular pertussis (DTaP); Haemophilus influenzae type b (Hib); Pneumococcal conjugate (PCV13); and Inactivated poliovirus (IPV). The rotavirus vaccine is also typically given. MMR, Varicella, and Hepatitis A vaccines are all first given at or after 12 months of age.

Question 3

1. DTaP, IPV, MMR, and Varicella (correct answer)
2. Tdap, IPV, and MMR
3. DTaP and IPV only
4. MMR and Varicella only

Explanation: According to the CDC immunization schedule, children should receive booster doses of certain vaccines between 4 and 6 years of age before starting school. This child is due for his fifth dose of DTaP, fourth dose of IPV, second dose of MMR, and second dose of varicella. He has only received one dose of MMR and varicella previously (typically given at 12-15 months), and the second doses are recommended at this age. He also needs boosters for DTaP and IPV. Tdap is not used for the primary series or boosters in children under age 7.

Question 4

1. Forward-facing car seat in the back seat
2. Rear-facing car seat in the back seat (correct answer)
3. Booster seat with a seatbelt in the back seat
4. Rear-facing car seat in the front passenger seat with the airbag disabled

Explanation: The American Academy of Pediatrics (AAP) recommends that all infants and toddlers ride in a rear-facing car seat for as long as possible, until they reach the highest weight or height allowed by their car seat's manufacturer. This provides the best protection for the head, neck, and spine in the event of a crash. A 6-month-old infant must be in a rear-facing car seat. All children under age 13 should ride in the back seat. Placing a rear-facing seat in the front is extremely dangerous due to the risk of injury from the passenger-side airbag.

Question 5

1. Triple diapering and follow-up in 2 weeks
2. Referral to an orthopedic surgeon (correct answer)
3. X-ray of the hips
4. Reassurance, as this is a common finding

Explanation: The physical examination findings describe a positive Barlow maneuver (dislocation of the hip with adduction) and a positive Ortolani maneuver (relocation of the dislocated hip with abduction). These findings are indicative of developmental dysplasia of the hip (DDH). A positive Ortolani or Barlow sign in an infant older than 2 weeks is a definitive indication for referral to an orthopedic surgeon for further evaluation and management, typically with a Pavlik harness. X-rays are not the preferred imaging modality in infants under 4-6 months because the femoral heads are cartilaginous; ultrasound is used instead. However, given the positive physical findings, direct referral is the most appropriate step. Triple diapering is ineffective and not recommended.

Question 6

1. Bring the child to the emergency department immediately
2. This is a normal reaction; manage with antipyretics and reassurance (correct answer)
3. Administer a dose of aspirin to reduce the fever
4. The child should not receive any further doses of the MMR vaccine

Explanation: The MMR vaccine is a live attenuated vaccine. A common and expected reaction, occurring 7-12 days after administration, is a fever and/or a mild rash. This represents a mild, non-contagious form of the measles infection as the body mounts an immune response. This reaction is self-limited and can be managed symptomatically with antipyretics (acetaminophen or ibuprofen). It is not an allergic reaction or a contraindication to future doses. Aspirin should be avoided in children due to the risk of Reye syndrome. Emergency department evaluation is not necessary for this expected vaccine reaction in an otherwise well-appearing child.

Question 7

1. Referral for physical therapy
2. X-ray of the lower extremities
3. Reassurance that this is within the normal range of development (correct answer)
4. Blood work including creatine kinase and thyroid studies

Explanation: The normal range for walking independently is broad, typically between 9 and 16 months. A child is not considered to have a significant gross motor delay until they are not walking by 18 months. This child is demonstrating appropriate prerequisite skills for walking, such as pulling to a stand and cruising. Her other developmental domains (language, fine motor) are also on track. Therefore, the most appropriate course of action is to reassure the parents that her development is within the normal range and to continue monitoring at subsequent well-child visits.

Question 8

1. Cranial ultrasound (correct answer)
2. Genetic testing for Sotos syndrome
3. Endocrine evaluation for hormonal abnormalities
4. Reassurance and follow-up in 1 month

Explanation: The rapid increase in head circumference crossing two major percentile lines, along with signs of increased intracranial pressure (tense fontanelle, split sutures, irritability), is highly concerning for hydrocephalus. In an infant with an open anterior fontanelle, a cranial ultrasound is the initial imaging modality of choice. It is non-invasive, does not require sedation, and can effectively visualize the ventricles to assess for dilation. MRI would be the next step if the ultrasound is abnormal or inconclusive. Reassurance is inappropriate given the red flags. While some genetic syndromes cause macrocephaly, the acute signs of increased pressure must be evaluated first.

Question 9

1. Serum lead level (correct answer)
2. Fasting lipid panel
3. Tuberculin skin test
4. Urinalysis

Explanation: Universal screening for lead exposure is recommended at 12 and 24 months of age for children enrolled in Medicaid or living in areas with a high prevalence of older housing. Even for other children, risk assessment is crucial. Living in a house built before 1978 (especially before 1960) is a major risk factor for lead exposure from paint chips and dust. Therefore, a serum lead level is indicated. A fasting lipid panel is not routinely recommended until ages 9-11. Tuberculin skin testing is only for children with specific risk factors. Urinalysis is not a routine screening test at this age in an asymptomatic child.

Question 10

1. Place the infant on her back to sleep on a firm surface (correct answer)
2. Use a soft mattress and bumper pads for comfort
3. Co-sleep with the infant in the parents' bed for close monitoring
4. Allow stomach sleeping once the infant can roll over independently

Explanation: The single most effective action to reduce the risk of SIDS is to place infants on their back ('supine') for every sleep, for naps and at night. This should be done on a firm, flat sleep surface without any soft bedding, pillows, or bumper pads. While infants who can roll from back to stomach and stomach to back independently can be allowed to remain in the sleep position they assume, parents should continue to place them on their back initially. Co-sleeping in the same bed is a risk factor for SIDS and suffocation and is discouraged. Room-sharing (infant in a separate bassinet or crib in the parents' room) is recommended.

Question 11

1. Inadequate caloric intake (correct answer)
2. Malabsorption due to celiac disease
3. Congenital heart disease
4. Chronic renal insufficiency

Explanation: This infant presents with failure to thrive, specifically affecting weight ('wasting') while length and head circumference are preserved. This pattern is classic for caloric insufficiency. The history points to several potential reasons for inadequate calories: the infant may not be getting enough calories from breast milk if the mother's diet is deficient, and the homemade pureed fruits and vegetables may be low in caloric and fat density compared to iron-fortified cereals and commercial baby foods. Other causes like celiac disease, heart disease, or renal disease are less likely given the preserved linear growth and lack of other specific symptoms.

Question 12

1. Global developmental delay
2. Isolated language disorder
3. Hearing impairment
4. Autism spectrum disorder (correct answer)

Explanation: The patient's presentation includes several red flags for autism spectrum disorder (ASD). These include impaired social communication and interaction (poor eye contact, not responding to name, lack of pointing for joint attention) and restricted, repetitive patterns of behavior or interests (lack of pretend play). While he does have a language delay, the social communication deficits are the most prominent and specific features pointing towards ASD. Hearing impairment should be ruled out, but it would not explain the lack of pointing or pretend play. Global developmental delay involves delays in at least two developmental domains, but this child's presentation is most characteristic of ASD.

Question 13

1. The child should receive prophylactic antibiotics for one year
2. He will require lifelong monitoring for autoimmune disease
3. This condition is self-limited and typically resolves within 1-2 weeks (correct answer)
4. He should be permanently restricted from contact sports

Explanation: Transient synovitis is the most common cause of hip pain in children aged 3-10. It is a benign, self-limited inflammatory condition that typically follows a viral illness and resolves within 1-2 weeks with supportive care (rest, NSAIDs). Parents should be counseled that this condition has no long-term consequences and does not require prolonged antibiotics, ongoing monitoring, or activity restrictions once resolved. Accurate counseling helps reduce parental anxiety and prevents unnecessary interventions.

Question 14

1. Continue iron-fortified formula and solids until age 2
2. Transition to 2% milk and limit to 16 ounces per day
3. Transition to whole milk and limit to 16-24 ounces per day (correct answer)
4. Transition to skim milk and encourage a variety of solids

Explanation: At 12 months of age, infants should transition from formula or breast milk to whole cow's milk. Whole milk is recommended until age 2 to provide adequate fat for brain development. Milk intake should be limited to 16-24 ounces per day to ensure the child does not fill up on milk and has an appetite for a variety of solid foods, which are crucial for obtaining iron and other nutrients. Excessive milk intake is a common cause of iron deficiency anemia in toddlers. 2% or skim milk is not recommended for children under 2 years. Continuing formula is unnecessary for a healthy, growing 1-year-old.

Question 15

1. Cerebral palsy
2. Brachial plexus injury (correct answer)
3. Spinal muscular atrophy
4. Congenital hypothyroidism

Explanation: An asymmetric Moro reflex is a classic red flag that points to a focal neurologic or musculoskeletal problem on the side with decreased movement. The most common cause of an asymmetric Moro reflex in a newborn is a brachial plexus injury (e.g., Erb's palsy) sustained during delivery. Other possibilities include a fractured clavicle or humerus. Cerebral palsy is typically not diagnosed in the newborn period and often presents with abnormalities of tone. Spinal muscular atrophy would cause symmetric weakness. Congenital hypothyroidism presents with poor feeding, hypotonia, and prolonged jaundice.

Question 16

1. Diphtheria, tetanus, acellular pertussis (DTaP)
2. Pneumococcal conjugate (PCV13)
3. Inactivated poliovirus (IPV)
4. Rotavirus (correct answer)

Explanation: The rotavirus vaccine is a live attenuated oral vaccine. The virus can be shed in the stool of the vaccinated infant for up to two weeks. This poses a theoretical risk of transmission to severely immunocompromised household contacts, such as the sibling receiving chemotherapy. Therefore, the live rotavirus vaccine should be withheld. All other recommended vaccines for a 2-month-old (DTaP, Hib, PCV13, IPV) are inactivated and can be safely administered to infants living with immunocompromised individuals.

Question 17

1. Formal audiology evaluation (correct answer)
2. Referral for developmental-behavioral pediatrics
3. Magnetic resonance imaging of the brain
4. Observation with follow-up in 6 months

Explanation: This patient presents with an expressive language delay. By age 2, a child should typically have a vocabulary of at least 50 words and be using two-word phrases. A crucial first step in the evaluation of any speech or language delay is to rule out hearing impairment. The child's history of recurrent otitis media further increases the suspicion for a conductive hearing loss due to middle ear effusion. A formal audiology evaluation is the definitive test to assess hearing ability. The other options are less appropriate as the initial step.

Question 18

1. Growth hormone deficiency
2. Constitutional growth delay
3. Familial short stature (correct answer)
4. Hypothyroidism

Explanation: This child's growth pattern is most consistent with familial short stature. Key features include a low-normal height percentile that is maintained consistently over time and a normal growth velocity (typically >4-5 cm/year for a preschooler). Although his parents are of 'average' height, their genetic potential may still place the child on a lower percentile. Growth hormone deficiency and hypothyroidism would typically present with a slowing of growth velocity and falling off the growth curve. Constitutional growth delay is characterized by a similar pattern but is often associated with delayed bone age and a later pubertal growth spurt, which cannot be determined yet in a 4-year-old, but familial short stature is more likely given he has been on this curve since birth.

Question 19

1. Hemoglobin A1c for diabetes
2. Non-fasting lipid panel for dyslipidemia (correct answer)
3. Serum lead level for lead toxicity
4. Thyroid-stimulating hormone for hypothyroidism

Explanation: The American Academy of Pediatrics (AAP) and the National Heart, Lung, and Blood Institute (NHLBI) recommend universal lipid screening for all children between the ages of 9 and 11. This is done to detect familial hypercholesterolemia and other lipid disorders early. A non-fasting panel is acceptable for initial universal screening. Screening for diabetes, lead toxicity, or hypothyroidism is not universally recommended at this age for an asymptomatic child without specific risk factors.

Question 20

1. She should receive the first dose now, as it can be given starting at age 6.
2. She should wait until age 11-12 to begin the vaccine series. (correct answer)
3. The vaccine is only recommended for sexually active adolescents.
4. She should receive it only if she has specific risk factors for HPV infection.

Explanation: The Advisory Committee on Immunization Practices (ACIP) routinely recommends HPV vaccination for all adolescents at age 11 or 12 years, although the series can be started as early as age 9. The goal is to complete the series before the onset of sexual activity, as the vaccine is most effective when given before any exposure to HPV. While it can be given at age 9, the routine recommendation is to start at age 11-12. It is a universal vaccine, not based on risk factors or sexual activity.