A 6-year-old boy presents to the pediatrician with his parents. He is fully vaccinated and met most developmental milestones. His fine motor milestones are delayed; at present, he cannot eat by himself and has difficulty in self-dressing. His intelligence quotient (IQ) is 65. He listens quietly while spoken to and engages in play with his classmates. He neither talks excessively nor remains mute, but engages in normal social conversation. There is no history of seizures and he is not on any long-term medical treatment. On his physical examination, his vital signs are stable. His height and weight are normal for his age and sex, but his occipitofrontal circumference is less than the 3rd percentile for his age and sex. His neurologic examination is also normal. Which of the following is the most likely diagnosis?
Q102
A 4-year-old boy presents with a recent history of frequent falls. The images below depict his movements when he tries to get up from the floor. Which of the following is the most likely diagnosis in this patient?
Q103
A 3-year-old boy is brought to the physician because of a 5-day history of yellowing of his eyes and skin. He has had generalized fatigue and mild shortness of breath over the past 2 months. Examination shows pale conjunctivae and scleral jaundice. The spleen is palpated 4 cm below the left costal margin. Laboratory studies show a hemoglobin concentration of 8.5 g/dL and a mean corpuscular volume of 76 μm3. A peripheral blood smear shows round erythrocytes that lack central pallor. Which of the following is the most likely cause of the splenomegaly seen in this child?
Q104
A 5-month-old girl is brought to the physician because of a red lesion on her scalp that was first noticed 2 months ago. The lesion has been slowly increasing in size. It is not associated with pain or pruritus. She was born at 37 weeks' gestation after an uncomplicated pregnancy and delivery. Her older sister is currently undergoing treatment for a fungal infection of her feet. Examination shows a solitary, soft lesion on the vertex of the scalp that blanches with pressure. A photograph of the lesion is shown. Which of the following is the most appropriate next step in management?
Q105
A 7-year-old girl is brought to the physician by her parents for the evaluation of pubic hair development. She has a history of a fracture in each leg and one fracture in her right arm. Her performance at school is good. There is no family history of serious illness. She takes no medications. Vital signs are within normal limits. Genital examination shows coarse, dark hair along the labia. The breast glands are enlarged and the breast bud extends beyond the areolar diameter. There are several hyperpigmented macules with rough, serpiginous borders of different sizes on the lower and upper extremities. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?
Q106
A 13-year-old female comes to your office complaining of dry, scaling skin (Figure A). She is particularly concerned about the appearance of her skin around her peers. She indicates that she did not start having problems until she was 5 years of age, after which her skin has progressively become drier and scalier. She has tried all types of over-the-counter moisturizers with no resolution. What is the most likely diagnosis?
Q107
A 2-year-old girl is brought to the physician by her mother for a well-child examination. She is at the 55th percentile for height and the 40th percentile for weight. Vital signs are within normal limits. Physical examination shows no abnormalities. She is able to follow simple commands, such as “close your eyes, then stick out your tongue,” but she is unable to follow 3-step commands. She knows approximately 75 words, and half of her speech is understandable. She can say 2-word phrases, and she is able to name many parts of the body. Assuming normal development, which of the following milestones would be expected in a patient this age?
Q108
A 3-year-old girl is brought to the physician by her parents for complaints of breast development and pubic hair growth for the past 6 months. She has no significant birth or medical history. The temperature is 37.0°C (98.6°F), the pulse is 88/min, and the respirations are 20/min. Physical examination shows enlarged breasts at Tanner stage 3 and pubic hair at stage 2. Height and weight are in the normal range. On GnRH stimulation testing, a luteinizing hormone (LH) response of < 5 IU/L is detected. What is the most appropriate next step in diagnosis?
Q109
A 3-year-old boy is brought to the physician because he is easily fatigued and has not gained weight. He eats 3 meals and has 3 to 4 bowel movements daily with bulky stools that float. He had recurrent episodes of sinusitis in infancy. He is at the 15th percentile for height and 5th percentile for weight. Examination shows pale conjunctivae. A few scattered expiratory crackles are heard in the thorax. There is abdominal distention. Which of the following is the most likely underlying cause of this patient's failure to thrive?
Q110
A 6-month-old girl is brought to the physician because of drooling and excessive crying for 3 days. She calms down when cuddled or with a pacifier in her mouth. She feeds well and has no vomiting or diarrhea. She was breastfed exclusively for 5 months. She is given no medications and was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines and is meeting all developmental milestones. At the clinic, her weight is 7.3 kg (16 lb 1 oz) and her height is 65.8 cm (25.9 in) in length. She appears irritable. Her pulse is 124/min, the respirations are 32/min, the blood pressure is 92/63 mm Hg, and the temperature is 36.8°C (98.2°F). On physical examination, she has no conjunctivitis, cervical lymphadenopathy, or pharyngeal erythema. Which element of the physical examination is most likely to be present in this patient?
Growth/Development US Medical PG Practice Questions and MCQs
Question 101: A 6-year-old boy presents to the pediatrician with his parents. He is fully vaccinated and met most developmental milestones. His fine motor milestones are delayed; at present, he cannot eat by himself and has difficulty in self-dressing. His intelligence quotient (IQ) is 65. He listens quietly while spoken to and engages in play with his classmates. He neither talks excessively nor remains mute, but engages in normal social conversation. There is no history of seizures and he is not on any long-term medical treatment. On his physical examination, his vital signs are stable. His height and weight are normal for his age and sex, but his occipitofrontal circumference is less than the 3rd percentile for his age and sex. His neurologic examination is also normal. Which of the following is the most likely diagnosis?
A. Attention deficit hyperactivity disorder
B. Autism
C. Intellectual disability (Correct Answer)
D. Obsessive-compulsive disorder
E. Tic disorder
Explanation: ***Intellectual disability***
- The boy's **IQ of 65** falls below the diagnostic threshold of 70 for intellectual disability, and he exhibits **adaptive deficits** in fine motor skills (difficulty eating and dressing) and **developmental delays**.
- His **microcephaly (occipitofrontal circumference less than 3rd percentile)** is also associated with certain forms of intellectual disability, further supporting this diagnosis.
*Attention deficit hyperactivity disorder*
- This condition is characterized by **inattention, hyperactivity, and impulsivity**, none of which are prominently described in the boy's presentation (he listens quietly and engages in normal conversation).
- While academic difficulties might occur, **significant adaptive and intellectual delays** as described are not typical primary features of ADHD.
*Autism*
- Autism spectrum disorder involves persistent deficits in **social communication and interaction** and **restricted, repetitive patterns of behavior, interests, or activities**.
- The boy's ability to engage in "normal social conversation" and play with classmates, along with an absence of repetitive behaviors or restricted interests, makes autism less likely.
*Obsessive-compulsive disorder*
- OCD is characterized by the presence of **obsessions (recurrent, persistent thoughts, urges, or images)** and/or **compulsions (repetitive behaviors or mental acts)**.
- The boy's symptoms do not include any mention of obsessions or compulsions.
*Tic disorder*
- Tic disorders involve **sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations**.
- There is no mention of tics in the boy's presentation, making this diagnosis unlikely.
Question 102: A 4-year-old boy presents with a recent history of frequent falls. The images below depict his movements when he tries to get up from the floor. Which of the following is the most likely diagnosis in this patient?
A. Cerebral palsy
B. Lambert-Eaton syndrome
C. Friedreich ataxia
D. Duchenne muscular dystrophy (Correct Answer)
E. Guillain-Barré syndrome
Explanation: ***Duchenne muscular dystrophy***
- The description of a 4-year-old boy with frequent falls and the depicted movements to get up from the floor (Gowers' sign) are classic presentations of **Duchenne muscular dystrophy (DMD)**.
- DMD is an **X-linked recessive disorder** characterized by progressive muscle weakness due to the absence of **dystrophin**.
*Cerebral palsy*
- **Cerebral palsy** is a group of permanent movement disorders that appear in early childhood and is caused by **abnormal brain development or damage**.
- While it can manifest with gait abnormalities and falls, it typically involves **spasticity**, ataxia, or dyskinesia, and does not specifically present with Gowers' sign from progressive muscle weakness.
*Lambert-Eaton syndrome*
- **Lambert-Eaton Myasthenic Syndrome (LEMS)** is an **autoimmune disorder** affecting the neuromuscular junction, leading to weakness that *improves* with repetitive muscle use.
- It most commonly affects adults, often in association with **small cell lung cancer**, and is characterized by proximal muscle weakness, not typically in a young child with this specific presentation.
*Friedreich ataxia*
- **Friedreich ataxia** is an **autosomal recessive neurodegenerative disease** that primarily affects the nervous system and heart.
- It presents with progressive gait and limb ataxia, dysarthria, and scoliosis, but not with **Gowers' sign** due to primary muscle weakness, which is specific to muscular dystrophies.
*Guillain-Barré syndrome*
- **Guillain-Barré syndrome (GBS)** is an acute, typically **post-infectious, autoimmune neuropathy** causing rapid onset of weakness, often ascending paralysis.
- It is an acute condition, not a chronic progressive disorder presenting in early childhood with Gowers' sign.
Question 103: A 3-year-old boy is brought to the physician because of a 5-day history of yellowing of his eyes and skin. He has had generalized fatigue and mild shortness of breath over the past 2 months. Examination shows pale conjunctivae and scleral jaundice. The spleen is palpated 4 cm below the left costal margin. Laboratory studies show a hemoglobin concentration of 8.5 g/dL and a mean corpuscular volume of 76 μm3. A peripheral blood smear shows round erythrocytes that lack central pallor. Which of the following is the most likely cause of the splenomegaly seen in this child?
A. Metabolite accumulation
B. Work hypertrophy (Correct Answer)
C. Neoplastic infiltration
D. Reticuloendothelial hyperplasia
E. Extramedullary hematopoiesis
Explanation: ***Work hypertrophy***
- The patient's presentation is consistent with **hereditary spherocytosis**, characterized by **hemolytic anemia**, jaundice, and **splenomegaly**.
- **Work hypertrophy** of the spleen's red pulp occurs due to its increased function in removing abnormal, rigid spherocytes from circulation, leading to its enlargement.
*Metabolite accumulation*
- This typically occurs in **lysosomal storage diseases** where defective enzymes lead to the buildup of specific metabolites within splenic macrophages.
- Conditions like **Gaucher disease** or **Niemann-Pick disease** cause splenomegaly through this mechanism, but do not present with spherocytes and hemolytic anemia.
*Neoplastic infiltration*
- This type of splenomegaly results from the infiltration of the spleen by **malignant cells**, such as in **leukemias** or **lymphomas**.
- While neoplastic infiltration can cause anemia, it is generally associated with different peripheral smear findings and systemic symptoms, not hereditary spherocytosis.
*Reticuloendothelial hyperplasia*
- While related to increased splenic activity, **reticuloendothelial hyperplasia** is a broader term encompassing the proliferation of macrophages and other immune cells in response to chronic infections or certain immune disorders.
- In hemolytic anemia, the primary driver of splenic enlargement is the excessive workload of removing red blood cells, which is best described as **work hypertrophy**.
*Extramedullary hematopoiesis*
- This refers to blood cell production occurring outside the bone marrow, often in the spleen or liver, as a compensatory mechanism in severe **bone marrow failure** or chronic hemolytic states.
- While it can contribute to splenomegaly in some chronic hemolytic anemias (e.g., thalassemia major), the primary cause of splenomegaly in hereditary spherocytosis is the *increased destruction* of abnormal RBCs by the spleen.
Question 104: A 5-month-old girl is brought to the physician because of a red lesion on her scalp that was first noticed 2 months ago. The lesion has been slowly increasing in size. It is not associated with pain or pruritus. She was born at 37 weeks' gestation after an uncomplicated pregnancy and delivery. Her older sister is currently undergoing treatment for a fungal infection of her feet. Examination shows a solitary, soft lesion on the vertex of the scalp that blanches with pressure. A photograph of the lesion is shown. Which of the following is the most appropriate next step in management?
A. Intralesional bevacizumab
B. Reassurance and follow-up (Correct Answer)
C. Systemic griseofulvin
D. Topical ketoconazole
E. Laser ablation
Explanation: ***Reassurance and follow-up***
- This presents a **superficial infantile hemangioma** (strawberry nevus), a benign vascular tumor appearing shortly after birth
- Key features include: red lesion, blanches with pressure, progressive growth during first months of life, soft consistency
- Most infantile hemangiomas are **self-resolving** with spontaneous involution typically beginning after 1 year of age
- **Observation and reassurance** are appropriate for uncomplicated lesions without functional impairment or significant cosmetic concern
- Proliferative phase lasts approximately 6-12 months, followed by gradual involution over several years
*Intralesional bevacizumab*
- Bevacizumab is an anti-VEGF monoclonal antibody used for certain cancers and macular degeneration
- Not a standard treatment for typical infantile hemangiomas
- Would only be considered in complex cases unresponsive to first-line therapies
*Systemic griseofulvin*
- Griseofulvin is an oral antifungal medication for dermatophyte infections of hair, skin, and nails
- The lesion's characteristics (red, vascular, blanching) are inconsistent with fungal infection
- Sister's fungal foot infection is a **red herring** and not relevant to this patient's diagnosis
*Topical ketoconazole*
- Ketoconazole is an antifungal agent for superficial fungal infections like tinea capitis or seborrheic dermatitis
- The lesion blanches with pressure (indicating vascular nature), ruling out fungal etiology
- Not appropriate despite family history of fungal infection
*Laser ablation*
- Pulsed dye laser may be used for hemangiomas that are ulcerated, in critical locations, or causing functional impairment
- Generally reserved for **complicated or resistant cases**, not first-line management
- This uncomplicated lesion is expected to resolve spontaneously without intervention
Question 105: A 7-year-old girl is brought to the physician by her parents for the evaluation of pubic hair development. She has a history of a fracture in each leg and one fracture in her right arm. Her performance at school is good. There is no family history of serious illness. She takes no medications. Vital signs are within normal limits. Genital examination shows coarse, dark hair along the labia. The breast glands are enlarged and the breast bud extends beyond the areolar diameter. There are several hyperpigmented macules with rough, serpiginous borders of different sizes on the lower and upper extremities. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?
A. Osteogenesis imperfecta
B. McCune-Albright syndrome (Correct Answer)
C. Congenital adrenal hyperplasia
D. Tuberous sclerosis
E. Neurofibromatosis type I
Explanation: ***McCune-Albright syndrome***
- This syndrome presents with the classic triad of **precocious puberty**, **polyostotic fibrous dysplasia** (leading to recurrent fractures), and **café-au-lait spots**. The patient's pubic hair, enlarged breast glands, history of fractures, and hyperpigmented macules fit this description.
- It is caused by a **somatic activating mutation** in the *GNAS* gene, leading to overproduction of hormones.
*Osteogenesis imperfecta*
- This condition is characterized by **brittle bones** and recurrent fractures, but it is typically associated with **blue sclerae**, **hearing loss**, and **dentinogenesis imperfecta**.
- It does not cause **precocious puberty** or **pigmented skin lesions**.
*Congenital adrenal hyperplasia*
- Patients typically present with **virilization** (e.g., precocious pubic hair), but it would also cause **clitoromegaly** and **hyperpigmentation of the genitalia**, along with electrolyte abnormalities depending on the enzyme deficiency.
- It is not associated with **recurrent fractures** or **café-au-lait spots**.
*Tuberous sclerosis*
- This neurocutaneous disorder is characterized by **seizures**, **intellectual disability**, and various skin lesions such as **ash-leaf spots**, **facial angiofibromas**, and **Shagreen patches**.
- It does not present with **precocious puberty**, **recurrent fractures**, or the specific type of **hyperpigmented macules** described.
*Neurofibromatosis type I*
- This condition is associated with numerous **café-au-lait spots** (usually smooth-bordered), **neurofibromas**, axillary and inguinal freckling, and Lisch nodules.
- It does not typically cause **precocious puberty** or **recurrent fractures** from fibrous dysplasia.
Question 106: A 13-year-old female comes to your office complaining of dry, scaling skin (Figure A). She is particularly concerned about the appearance of her skin around her peers. She indicates that she did not start having problems until she was 5 years of age, after which her skin has progressively become drier and scalier. She has tried all types of over-the-counter moisturizers with no resolution. What is the most likely diagnosis?
A. Atopic dermatitis
B. Seborrheic dermatitis
C. Miliaria
D. Psoriasis
E. Ichthyosis vulgaris (Correct Answer)
Explanation: ***Ichthyosis vulgaris***
- This condition is characterized by **dry, scaling skin** that often appears in childhood (around age 5) and progressively worsens, fitting the patient's history.
- It is caused by a **mutation in the filaggrin gene**, leading to impaired skin barrier function and increased transepidermal water loss.
*Atopic dermatitis*
- While it presents with **dry skin and can be severe**, it is typically characterized by **eczematous lesions** (red, inflamed, itchy patches) and a history of allergies or asthma.
- The patient describes "dry, scaling skin" without mentioning significant itching or inflammation often seen in atopic dermatitis.
*Seborrheic dermatitis*
- This condition presents with **greasy, yellowish scales** on areas rich in sebaceous glands, such as the scalp, face, and chest.
- It does not typically manifest as widespread dry, scaling skin that progressively worsens throughout childhood.
*Miliaria*
- Also known as **heat rash** or prickly heat, miliaria results from blocked sweat ducts and manifests as small, itchy bumps or blisters, often in humid conditions.
- It is an acute condition and does not present as chronic, progressively worsening dry, scaling skin.
*Psoriasis*
- Psoriasis typically presents with **well-demarcated, erythematous plaques** covered with silvery scales, often on extensor surfaces like elbows and knees.
- While it involves scaling, the description of "dry, scaling skin" that progressively worsens from childhood fits ichthyosis more precisely than the characteristic plaques of psoriasis.
Question 107: A 2-year-old girl is brought to the physician by her mother for a well-child examination. She is at the 55th percentile for height and the 40th percentile for weight. Vital signs are within normal limits. Physical examination shows no abnormalities. She is able to follow simple commands, such as “close your eyes, then stick out your tongue,” but she is unable to follow 3-step commands. She knows approximately 75 words, and half of her speech is understandable. She can say 2-word phrases, and she is able to name many parts of the body. Assuming normal development, which of the following milestones would be expected in a patient this age?
A. Hops on one foot
B. Engages in role-playing
C. Separates easily from parents
D. Pedals a tricycle
E. Builds a tower of 6 cubes (Correct Answer)
Explanation: ***Builds a tower of 6 cubes***
- At 2 years old, children typically develop fine motor skills enabling them to stack **6 to 7 cubes** to build a tower, demonstrating good hand-eye coordination.
- This milestone aligns well with the described cognitive development, such as following multi-step commands and early language acquisition.
*Hops on one foot*
- **Hopping on one foot** is a gross motor skill usually achieved later, typically around **4 years of age**.
- A 2-year-old child is more likely to be developing skills like running, jumping with two feet, or walking up and down stairs.
*Engages in role-playing*
- While toddlers engage in **imitative play**, true imaginative **role-playing** with complex scenarios and multiple characters typically develops later, around **3 years of age or older**.
- At 2, play is often more focused on mimicking observed actions.
*Separates easily from parents*
- At 2 years old, many children are still experiencing **separation anxiety**, especially in unfamiliar situations.
- **Easy separation** from parents is a milestone typically achieved later as children develop more independence and social confidence, often closer to 3 or 4 years of age.
*Pedals a tricycle*
- **Pedaling a tricycle** requires coordinated gross motor skills, balance, and cognitive understanding that are typically developed around **3 years of age**.
- A 2-year-old may be able to sit on a tricycle and push with their feet, but not yet pedal efficiently.
Question 108: A 3-year-old girl is brought to the physician by her parents for complaints of breast development and pubic hair growth for the past 6 months. She has no significant birth or medical history. The temperature is 37.0°C (98.6°F), the pulse is 88/min, and the respirations are 20/min. Physical examination shows enlarged breasts at Tanner stage 3 and pubic hair at stage 2. Height and weight are in the normal range. On GnRH stimulation testing, a luteinizing hormone (LH) response of < 5 IU/L is detected. What is the most appropriate next step in diagnosis?
A. Perform leuprolide stimulation test to measure testosterone
B. Measure baseline estradiol levels and perform pelvic ultrasound (Correct Answer)
C. Measure FSH levels to evaluate pituitary function
D. Calculate LH:FSH ratio from previous GnRH test
E. Repeat GnRH stimulation test to confirm LH response
Explanation: ***Measure baseline estradiol levels and perform pelvic ultrasound***
- This patient presents with **precocious puberty** (breast development and pubic hair at age 3). The **low LH response** (<5 IU/L) to GnRH stimulation confirms **peripheral (gonadotropin-independent) precocious puberty**.
- In peripheral precocious puberty, sex hormones are produced **autonomously** (independent of pituitary control), which **suppresses** the hypothalamic-pituitary-gonadal axis through negative feedback.
- The next step is to **identify the source** of autonomous sex hormone production. **Measuring estradiol levels** confirms elevated estrogen, and **pelvic ultrasound** evaluates for ovarian causes such as **ovarian cysts** or **tumors** (e.g., granulosa cell tumor), which are common causes of peripheral precocious puberty in girls.
- Other causes to consider include **McCune-Albright syndrome** (café-au-lait spots, polyostotic fibrous dysplasia) or exogenous estrogen exposure.
*Measure FSH levels to evaluate pituitary function*
- Measuring FSH is **not helpful** in this clinical context because the low LH response to GnRH stimulation **already indicates** that the pituitary is suppressed.
- In peripheral precocious puberty, both LH and FSH are **suppressed** due to negative feedback from peripherally produced sex hormones. Measuring FSH would simply confirm what we already know - that the pituitary axis is not activated.
- The priority is to find the **source** of the sex hormones, not to further characterize pituitary suppression.
*Perform leuprolide stimulation test to measure testosterone*
- Leuprolide is a **GnRH agonist** used to evaluate **central precocious puberty**, where the HPG axis is prematurely activated.
- This test is **not indicated** for peripheral precocious puberty, which has already been confirmed by the low LH response.
- Additionally, measuring testosterone would not be useful in a female patient presenting with estrogenic signs (breast development).
*Calculate LH:FSH ratio from previous GnRH test*
- The **LH:FSH ratio** is useful in diagnosing **central precocious puberty**, where an LH-predominant response (LH:FSH ratio >0.6-1.0) is characteristic.
- Since the LH response is already **low** (<5 IU/L), confirming peripheral precocious puberty, this ratio would not provide diagnostic value.
- The focus should be on investigating the **peripheral source** of sex hormones.
*Repeat GnRH stimulation test to confirm LH response*
- Repeating the GnRH stimulation test is **unnecessary** when the initial test provides clear results.
- The low LH response (<5 IU/L) definitively indicates peripheral precocious puberty, and repeating the test would only delay appropriate diagnostic workup for the underlying cause.
Question 109: A 3-year-old boy is brought to the physician because he is easily fatigued and has not gained weight. He eats 3 meals and has 3 to 4 bowel movements daily with bulky stools that float. He had recurrent episodes of sinusitis in infancy. He is at the 15th percentile for height and 5th percentile for weight. Examination shows pale conjunctivae. A few scattered expiratory crackles are heard in the thorax. There is abdominal distention. Which of the following is the most likely underlying cause of this patient's failure to thrive?
A. Impaired intestinal amino acid transport
B. Mucosal damage from excessive gastric acid
C. Intestinal inflammatory reaction to gluten
D. Small intestine bacterial overgrowth
E. Exocrine pancreatic insufficiency (Correct Answer)
Explanation: **Exocrine pancreatic insufficiency**
- The patient's presentation with **failure to thrive**, **bulky, floating stools** (suggestive of **steatorrhea**), abdominal distension, and recurrent sinusitis points strongly towards **cystic fibrosis**.
- **Cystic fibrosis** is a genetic disorder causing thick, viscous secretions that obstruct exocrine ducts, most notably in the **pancreas** (leading to malabsorption) and respiratory tract (recurrent infections).
*Impaired intestinal amino acid transport*
- This condition is typically associated with specific genetic disorders like **Hartnup disease** or **cystinuria**, which primarily affect amino acid absorption without the widespread symptoms seen here.
- While it can contribute to nutritional deficiencies, it does not explain the **respiratory symptoms** or the characteristic **fat malabsorption** implied by floating stools.
*Mucosal damage from excessive gastric acid*
- This might suggest conditions like **Zollinger-Ellison syndrome** or severe GERD, which can cause malabsorption due to inactivation of pancreatic enzymes or damage to the small intestine.
- However, it does not account for the **recurrent sinusitis** or the specific type of malabsorption (steatorrhea) typically associated with pancreatic insufficiency.
*Intestinal inflammatory reaction to gluten*
- This describes **celiac disease**, which presents with **malabsorption**, abdominal distension, and failure to thrive.
- However, **celiac disease** is not typically associated with **recurrent sinusitis** or the early-onset, severe growth failure and pulmonary issues often seen in cystic fibrosis.
*Small intestine bacterial overgrowth*
- SIBO can cause **malabsorption**, abdominal distension, and failure to thrive, but it does not directly lead to **recurrent sinusitis**.
- While SIBO can be a complication of other malabsorptive conditions, it is not the primary underlying cause suggested by the comprehensive clinical picture, especially the respiratory component.
Question 110: A 6-month-old girl is brought to the physician because of drooling and excessive crying for 3 days. She calms down when cuddled or with a pacifier in her mouth. She feeds well and has no vomiting or diarrhea. She was breastfed exclusively for 5 months. She is given no medications and was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines and is meeting all developmental milestones. At the clinic, her weight is 7.3 kg (16 lb 1 oz) and her height is 65.8 cm (25.9 in) in length. She appears irritable. Her pulse is 124/min, the respirations are 32/min, the blood pressure is 92/63 mm Hg, and the temperature is 36.8°C (98.2°F). On physical examination, she has no conjunctivitis, cervical lymphadenopathy, or pharyngeal erythema. Which element of the physical examination is most likely to be present in this patient?
A. The rooting reflex
B. Crying on frontal sinus palpation
C. Eruption of mandibular incisors (Correct Answer)
D. Closure of the anterior fontanel
E. Erythema and fluctuance of the submandibular area
Explanation: ***Eruption of mandibular incisors***
- The patient's age (6 months), **drooling**, and **irritability** strongly suggest **teething**, which commonly involves the eruption of the mandibular incisors.
- Teething pain and discomfort can be relieved by pacifiers or cuddling, consistent with the patient's presentation.
*The rooting reflex*
- The **rooting reflex** is a primitive reflex typically present at birth and usually disappears by **4 months of age**; this patient is 6 months old.
- Its presence would not explain the current symptoms of irritability and drooling.
*Crying on frontal sinus palpation*
- **Frontal sinuses** are typically underdeveloped or absent in infants and children until later ages (around 6-10 years old), so their palpation is not clinically relevant in a 6-month-old.
- Crying on palpation would only be significant if the sinuses were developed and inflamed, which is unlikely and not indicated by other symptoms.
*Closure of the anterior fontanel*
- The **anterior fontanel** typically remains open until **12-18 months of age**, allowing for brain growth; abnormal closure at 6 months would be a concerning finding but is not indicated by the drooling and irritability.
- Premature closure of the fontanel is usually associated with microcephaly or other cranial abnormalities, not teething symptoms.
*Erythema and fluctuance of the submandibular area*
- **Erythema** and **fluctuance** in the submandibular area suggest an **infection or abscess**, which would likely be accompanied by fever and other signs of systemic illness not present in this patient.
- While teething can cause local inflammation, it does not typically lead to a submandibular abscess without other contributing factors.