A 42-year-old man who is employed as a construction worker presents to his primary care physician with complaints of moderate headaches and profuse sweating. He reports the need to carry up to 3 additional shirt changes to work because they drench quickly even with tasks of low physical exertion. His coworkers have commented about his changing glove and boot sizes, which have increased at least 4 times since he joined the company 10 years ago. Physical examination is unremarkable except for blood pressure of 160/95 mm Hg, hyperhidrosis, noticeably large pores, hypertrichosis, widely spaced teeth, and prognathism. Which of the following best explains the patient’s clinical manifestations?

Increased serum insulin-like growth factor 1 (IGF-1)

Increased thyroid-stimulating hormone

A 5-year-old boy presents to the pediatrician for a well child visit. He is meeting his developmental milestones and is in the 15th percentile for height and 70th percentile for weight. His parents report that he complains of fatiguing easily and having trouble participating in sports. They are concerned he is not getting enough sleep and state that sometimes they hear him snore. The patient has a past medical history of a supracondylar fracture of the humerus, which was appropriately treated. He is doing well in school but is sometimes bullied for being small. The patient eats a balanced diet of milk, fruit, and some vegetables. His parents have been trying to get him to drink more milk so he can grow taller. His temperature is 99.5°F (37.5°C), blood pressure is 90/48 mmHg, pulse is 100/min, respirations are 19/min, and oxygen saturation is 98% on room air. On physical exam, the patient appears well. HEENT exam is notable for conjunctival pallor and a unilateral clear middle ear effusion. Cardiac exam reveals a benign flow murmur. Pulmonary exam is clear to auscultation bilaterally. The patient's gait is stable and he is able to jump up and down. A full set of labs are ordered as requested by the parents including a serum vitamin D level, B12 level, and IGF level. A selection of these lab values are seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 4.3 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 1.1 mg/dL Ca2+: 9.9 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following would you expect to find in this patient?

Decreased oxygen saturation when the patient sleeps

An 8-year-old boy presents to his pediatrician for a well visit. His parents state that he has been doing well in school and has many friends. The patient is a member of the chess club and enjoys playing video games. He has a past medical history of asthma which is treated with albuterol. The patient is in the 99th percentile for weight and 30th percentile for height. His temperature is 99.5°F (37.5°C), blood pressure is 122/88 mmHg, pulse is 90/min, respirations are 11/min, and oxygen saturation is 98% on room air. The patient's body mass index is 39.1 kg/m^2 at this visit. On physical exam, you note a young boy who maintains eye contact and is excited to be at the doctor's office. Cardiopulmonary exam is within normal limits. Abdominal exam reveals normal bowel sounds and is non-tender in all 4 quadrants. Neurological and musculoskeletal exams are within normal limits. Which of the following is the most likely outcome in this patient?

Slipped capital femoral epiphysis

An 18-month-old boy is brought to the physician by his mother because of concern that he has not yet begun to walk. He was born at term and exclusively breastfed until 15 months of age. His mother says he has been well, apart from an episode of high fever and seizure 4 months ago for which she did not seek medical attention. He has an older brother who is currently receiving medical treatment for failure to thrive. His parents have no history of serious illness; they are of normal height. His last vaccine was at the age of 4 months. He is at the 20th percentile for length, 10th percentile for weight, and 50th percentile for head circumference. Physical examination shows dry mucous membranes and erosion of the enamel on the lingual surface of the incisors and carious molars. He has frontal bossing. His wrists are widened, his legs seem bent, and there is beading of the ribs. Which of the following is the most likely underlying cause of this patient's delay in walking?

Defective growth plate mineralization

Deficiency of osteoclasts to reabsorb bone

Osteoid proliferation in the subperiosteal bone

Mutation of fibroblast growth factor receptor 3

A pathologist receives a skin biopsy specimen from a patient who is suspected to have developed graft-versus-host disease (GVHD) following allogeneic stem-cell transplantation. The treating physician informs the pathologist that he is specifically concerned about the diagnosis as the patient developed skin lesions on the 90th-day post-transplantation and therefore, by definition, it should be considered a case of acute GVHD. However, the lesions clinically appear like those of chronic GVHD. The pathologist examines the slide under the microscope and confirms the diagnosis of chronic GVHD. Which of the following findings on skin biopsy is most likely to have helped the pathologist to confirm the diagnosis?

Complete separation of the dermis and epidermis

Focal vacuolization in the basal cell layer

Lymphocytic infiltration of the superficial dermis

Diffuse vacuolization in the basal cell layer

Impact of chronic disease on growth for USMLE Step 2 CK: High-Yield Pediatrics Lessons

Pathophysiology - The Growth Thief

Nutritional Deficit: The core issue. Results from ↓intake (anorexia), malabsorption, or ↑metabolic demand, diverting calories from growth.
Inflammatory Cytokine Storm:
- Key mediators: TNF-α, IL-1, IL-6.
- Effects: Induce anorexia, ↑catabolism, and cause Growth Hormone (GH) resistance.
Hormonal Dysregulation:
- GH-IGF-1 Axis Disruption: ↓IGF-1 (the "workhorse" of growth) despite normal/↑GH.
- Glucocorticoid Excess: Directly inhibits cartilage growth in the epiphyseal plate.
- Hypogonadism: Delays pubertal growth spurt.
Direct Tissue Insults:
- Chronic acidosis (e.g., RTA) and hypoxia (e.g., cyanotic heart disease) impair cellular growth processes.

GH-IGF-1 Axis in Growth Disorders

⭐ The key hormonal finding in growth failure of chronic disease is GH resistance: characterized by normal or ↑GH levels with paradoxically ↓IGF-1 levels.

System-Specific Impacts - Disease Deep Dive

Congenital Heart Disease (CHD):
- Cyanotic CHD > Acyanotic CHD for growth impact.
- Mechanisms: Chronic hypoxia, increased caloric needs, feeding difficulties.
Chronic Kidney Disease (CKD):
- Key factors: Metabolic acidosis, renal osteodystrophy, anemia, and growth hormone (GH) resistance.
- Uremic toxins disrupt the GH-IGF-1 axis.
Gastrointestinal (IBD - Crohn's):
- Mechanisms: Malabsorption, systemic inflammation (↑ TNF-α, IL-6), and poor appetite.
- Weight is affected more than height initially.

⭐ In Crohn's disease, growth failure can be the sole presenting feature, preceding GI symptoms by years.

Weight-for-age growth charts for children with IBD

Assessment - Growth Detective Work

History is Key: Detailed 3-day dietary recall, systemic symptoms (fever, diarrhea, pain), birth history, and developmental milestones.
Clinical Clues:
- Weight-for-height (Wasting): Indicates acute malnutrition.
- Height-for-age (Stunting): Indicates chronic malnutrition.
- Look for specific signs: pallor, edema, clubbing, organomegaly.
Core Investigations:
- Bone Age X-ray (left hand & wrist): Crucial; often delayed more than chronological age.
- Screening Labs: CBC, ESR, CRP, Urinalysis, Stool exam, LFT, KFT.

⭐ In nutritional growth failure, the sequence of impact is always: Weight → Height → Head Circumference.

Management - The Growth Boosters

Nutritional Rehabilitation: Cornerstone of management.
- High-calorie diets: ↑ intake by 25-50% over RDA.
- Enteral feeds (NG/gastrostomy) if oral intake is inadequate.
- Micronutrient supplementation (Iron, Zinc, Vit D).
Disease-Specific Therapy: Treat the underlying condition aggressively.
- e.g., Anti-TNF agents in Crohn's disease, gluten-free diet in Celiac disease.
Hormonal Therapy: For persistent growth failure despite other measures.
- Recombinant Human Growth Hormone (rhGH).
- Indications: Chronic Renal Insufficiency (CRI), Turner Syndrome, SGA.
- Dose for CRI: 0.045-0.050 mg/kg/day.

⭐ In Chronic Renal Insufficiency, rhGH therapy is approved for pre-dialysis patients to promote catch-up growth before transplantation.

High‑Yield Points - ⚡ Biggest Takeaways

Chronic disease first impacts weight, then height, and lastly head circumference.

The most common mechanism is inadequate caloric intake due to anorexia or malabsorption.

Catch-up growth is a key feature and occurs once the underlying disease is controlled.

Bone age is a more reliable indicator of growth potential than chronological age and is usually delayed.

Growth failure is most severe during infancy and puberty.

Consider endocrinopathies (hypothyroidism) and renal disease as non-nutritional causes.

Continue reading on Oncourse

CONTINUE READING — FREE

or get the app

App Store|Google Play