Failure to thrive (FTT) is the inability to maintain a normal growth pattern in weight, stature, and occasionally in head growth. Definitions are varied and include a fall in weight below the 2nd percentile relative to corrected gestational age and sex or growth deceleration that crosses two major percentiles on a standardized growth chart. It is most common in infancy, and the condition is nonorganic (50%), organic (25%), or mixed (25%) in etiology. The diagnosis is made after complete history and physical examination with comparison of the measurements of length (supine in children < 3 years of age), weight, and head circumference (maximal occipital-frontal circumference) to standard measurements. In cases of deficient caloric intake or malabsorption, the patient’s head circumference is normal and the weight is reduced out of proportion to length/height. In general, FTT is due to decreased intake, increased output, increased caloric demand, or some combination of all three. The differential diagnosis of FTT is lengthy. Nonorganic disorders are more common and include poor feeding technique, disturbed maternal-child interaction, emotional deprivation, inadequate caloric intake, and child neglect. Organic causes are numerous.
Failure to Thrive. This infant has not been able to maintain a normal growth pattern. Note skin folds in upper extremities due to loss of subcutaneous fat. (Photo contributor: Lawrence B. Stack, MD.)
Management and Disposition
Depending on history, physical findings, the social situation, and ability to ensure close monitoring by a primary care physician, most cases can be managed as outpatients. The primary care provider can assist in determining whether outpatient management is indicated. If the diagnosis of FTT is made in the emergency department, admission is suggested to complete the evaluation. That the child presented to the emergency department could be the only indicator of a poor social environment or inadequate access to medical care. Simple initial testing includes CBC, urinalysis, electrolytes, BUN, creatinine, ESR, and CRP. If the history and physical exam suggest it, liver function tests, screening thyroid studies, prealbumin, and lead testing are appropriate. For very young infants, it is important to document a normal newborn screen. Early involvement of social services may facilitate the evaluation and follow-up. Treatment will vary according to the underlying disorder and often involves a team approach.
FTT in neglected children is accompanied by signs of developmental delays, emotional deprivation, apathy, poor hygiene, withdrawn behavior, and poor eye contact.
The major contributor to FTT is caloric inadequacy. Dietary history should include details of formula preparation, volume consumed, and, in toddlers, the volume of juice consumed.
Failure to Thrive. Accentuation of the gluteal folds secondary to loss of subcutaneous fat in an infant with FTT. (Photo contributor: Andrew H. Urbach, MD.)