Differential Diagnosis for a 9-Year-Old Boy Who Eats Plenty but is Always Sick and Skinny
- Single Most Likely Diagnosis
- Celiac Disease: This condition is characterized by an immune reaction to gluten, leading to malabsorption of nutrients. It's a common cause of failure to thrive in children, despite adequate food intake.
- Other Likely Diagnoses
- Gastroesophageal Reflux Disease (GERD): Chronic vomiting or discomfort after eating can lead to malnutrition and failure to gain weight.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic inflammation, leading to malabsorption and weight loss.
- Cystic Fibrosis: Although less common, this genetic disorder can cause malabsorption due to pancreatic insufficiency, leading to poor growth and frequent illnesses.
- Chronic Infections (e.g., tuberculosis, parasitic infections): Recurrent or persistent infections can consume the body's energy and nutrients, leading to weight loss and failure to thrive.
- Do Not Miss Diagnoses
- Diabetes Mellitus: Uncontrolled diabetes can lead to weight loss and failure to thrive due to excessive glucose loss in the urine.
- HIV/AIDS: Immunodeficiency can cause chronic illnesses, malabsorption, and failure to gain weight.
- Lymphoma or other malignancies: Although rare, cancer can cause unexplained weight loss, fatigue, and recurrent illnesses in children.
- Rare Diagnoses
- Congenital disorders of glycosylation: These are a group of rare genetic disorders affecting the body's ability to properly glycosylate proteins, leading to malabsorption and failure to thrive.
- Mitochondrial disorders: Conditions like Kearns-Sayre syndrome or Pearson syndrome can cause malabsorption, weight loss, and failure to thrive due to mitochondrial dysfunction.
- Chronic intestinal pseudo-obstruction: This rare condition is characterized by impaired intestinal motility, leading to malabsorption, weight loss, and recurrent illnesses.