Differential Diagnosis for a 17-month-old Male with Weight Below Expected for Corrected Age

• Single Most Likely Diagnosis:
  • Failure to Thrive (FTT): The patient's weight is below expected for corrected age, and despite the mother's report of adequate intake, the child is not gaining weight as expected. This, combined with a history of prematurity, makes FTT a likely diagnosis.
• Other Likely Diagnoses:
  • Inadequate Nutrition: Despite the mother's report of adequate intake, it's possible that the child is not receiving sufficient calories or nutrients for growth, which could be due to inappropriate supplementation or feeding practices.
  • Gastroesophageal Reflux Disease (GERD): This condition can lead to feeding difficulties and poor weight gain, especially in premature infants.
  • Developmental Delay or Disorder: Children with developmental delays or disorders may have feeding difficulties or poor appetite, leading to inadequate weight gain.
• Do Not Miss Diagnoses:
  • Cystic Fibrosis: A genetic disorder that can cause malabsorption and poor weight gain, despite adequate calorie intake.
  • Celiac Disease: An autoimmune disorder that can cause malabsorption and poor weight gain if left untreated.
  • Hypothyroidism: A condition that can cause growth delays and poor weight gain if left untreated.
  • Inborn Errors of Metabolism: A group of genetic disorders that can cause poor weight gain, developmental delays, and other systemic problems.
• Rare Diagnoses:
  • Chromosomal Abnormalities (e.g., Turner Syndrome): Certain chromosomal abnormalities can cause growth delays and poor weight gain.
  • Congenital Heart Disease: Untreated congenital heart disease can cause poor weight gain and growth delays due to increased energy expenditure.
  • Chronic Infections (e.g., HIV, Tuberculosis): Chronic infections can cause poor weight gain and growth delays due to increased energy expenditure and malabsorption.
  • Genetic Syndromes (e.g., Prader-Willi Syndrome): Certain genetic syndromes can cause poor weight gain and growth delays, often with other systemic features.