📊 Definition
• Inadequate growth (weight > length/height affected first)
• Weight <5th percentile OR weight <80% ideal for age
• Crossing ≥2 major percentile lines (downward)
• Multifactorial: most cases due to inadequate nutrition from complex biologic/environmental factors
🩺 Causes by Mechanism
• Inadequate intake (most common): poor feeding, neglect, formula mixing errors, oral-motor dysfunction, GER, food allergy
• Malabsorption: celiac disease, CF, pancreatic insufficiency, IBD, protein-losing enteropathy
• Increased metabolic demand: hyperthyroidism, chronic infection, heart disease, malignancy
• Defective utilization: inborn errors of metabolism
⚠️ Red Flags for Organic Disease
• Onset since birth (congenital, chromosomal, metabolic)
• Deceleration of head circumference (microcephaly)
• Dysmorphic features, organomegaly, chronic diarrhea
• Vomiting (especially bilious or projectile)
• Recurrent infections, failure to pass meconium (Hirschsprung)
📋 Evaluation & Management
• Detailed diet/feeding history (24-hour recall)
• Plot accurate growth measurements (WHO charts <2 years)
• Initial labs: CBC, ESR, CRP, electrolytes, LFTs, UA, lead, celiac screen (TTG IgA)
• Sweat chloride test if CF suspected
• Hospitalization for severe malnutrition, suspected abuse/neglect, or failed outpatient management
📌 Decision strategy: Most FTT is psychosocial/environmental (inadequate intake). Organic causes are less common. Weight loss before length/height loss indicates malnutrition. Caloric trial ± multi-disciplinary team improves outcomes.