Diagnostic Algorithm for a Child with Failure to Thrive (FTT)

Definition of Failure to Thrive (FTT)

Failure to thrive (FTT) is a condition in which a child’s growth is significantly below the expected norms for their age and sex. It is typically defined as:

Weight below the 3rd or 5th percentile for age on standardized growth charts.
Weight-for-height or BMI below the 3rd percentile.
Crossing two or more major growth percentiles downward over time.

Step 1: History & Physical Examination

Anthropometric assessment:
Weight, height, head circumference, BMI (plot on growth charts).
Compare with previous growth trends.
Detailed history:
Dietary: Breastfeeding, formula intake, complementary feeding, feeding techniques.
Medical: Prematurity, congenital diseases, chronic infections, GI symptoms (vomiting, diarrhea, constipation).
Family: Parental heights, growth patterns, genetic conditions.
Social/Psychosocial: Parental stress, neglect, poverty, caregiver-child interaction.
Physical examination:
Malnutrition signs: Muscle wasting, dry skin, brittle hair.
Systemic examination: Cardiac murmurs (congenital heart disease), hepatosplenomegaly (chronic infections/metabolic disorders), neurodevelopmental delay (cerebral palsy, metabolic disorders).

Step 2: Identify Organic vs. Non-Organic FTT

Organic FTT: Due to medical conditions affecting nutrient intake, absorption, or metabolism.
Non-Organic FTT (NOFTT): Due to environmental, psychosocial, or behavioral factors without a medical cause.

Step 3: Laboratory Workup (If organic cause suspected)

Basic labs:
CBC (anemia, infection).
Electrolytes, renal/liver function tests (metabolic disorders).
Urinalysis (renal disease, UTI).
Nutritional evaluation:
Serum albumin, prealbumin (malnutrition).
Iron, zinc, vitamin D levels.
Endocrine & metabolic:
Thyroid function tests (hypothyroidism).
Blood glucose (diabetes, metabolic disorders).
Gastrointestinal:
Stool for fat, reducing substances (malabsorption).
Celiac serology (celiac disease).
Sweat chloride test (cystic fibrosis).
Genetic testing:
If dysmorphic features, neurodevelopmental delay, or syndromic suspicion.

Management Based on Cause

Non-Organic Failure to Thrive (NOFTT)

Primary issue: Inadequate caloric intake due to psychosocial factors.
Interventions:
Parent/caregiver education: Feeding techniques, appropriate nutrition.
Caloric supplementation: High-energy, protein-rich diet.
Behavioral therapy: For feeding aversion.
Social work referral: Assess home environment, food security.
Close follow-up: Monitor weight gain weekly or biweekly.

Organic Failure to Thrive (OFTT) (Treat underlying cause)

GI disorders (GERD, celiac disease, malabsorption) → Specialized diets, enzyme replacement.
Endocrine (hypothyroidism, growth hormone deficiency) → Hormonal therapy.
Chronic illnesses (congenital heart disease, cystic fibrosis, chronic infections) → Disease-specific management.

Red Flags Indicating Urgent Evaluation

Severe malnutrition (weight-for-height < -3 SD).
Signs of neglect or abuse.
Failure to gain weight despite adequate caloric intake.
Developmental regression or neurological signs.