Failure to thrive

Background

Non-specific term indicating inappropriate weight loss or insufficient weight gain, due to insufficient caloric intake, caloric absorption, or excessive caloric demand.
Separated into pediatric and adult (often seen in geriatric populations or in those with chronic illnesses).

Defined as weighing <5th percentile for age and sex, or weight deceleration crossing two major growth lines on a growth chart.
Does not imply a defect in social, intellectual, or emotional development, but if untreated may lead to any combination of those.
Classically divided into endogenous (medical) and exogenous (psychosocial or environmental) causes

A detailed history and physical examination (including accurate height and weight) are usually sufficient to establish a cause. Over 80% of cases are due to insufficient caloric intake from exogenous causes.
- History should focus on breastfeeding technique, frequency, and duration, or amount of formula and method of preparation.
- Observed feeds can often be useful to identify problems.
If an endogenous cause is suspected, specific lab tests or imaging studies may be helpful to evaluate for metabolic abnormalities, the presence of infections, malignancy, or anatomic malformations. Additional testing should be ordered on a case by case basis and is only recommended if a specific etiology is suspected.