Nonorganic Failure-to-Thrive

The infant with failure to thrive poses a formidable dilemma. On the one hand, the differential diagnosis of the infant with poor growth or weight loss is practically coextensive with the lexicon of serious disease in childhood; on the other hand, the indiscriminant "ruling out" of one occult possibility after another assures only high cost, iatrogenic complications, persistent anxiety, and, in most cases, diagnostic failure. The evaluation of failure-to-thrive (FTT) cannot be efficient if the physician investigates nonorganic etiologies only after exhaustively exploring all imaginable organic causes. Emotional or environmental disorders so frequently lie at the root of growth failure that the physician should consider these nonorganic etiologies, like any common causes, in parallel with (and often before) the search for occult organic disease. PREVALENCE OF ORGANIC AND NONORGANIC FTT FTT (usually defined as a weight persistently below the third percentile for age, or weight less than 80% of ideal weight for age) is a common problem, accounting for 3% to 5% of admissions to pediatric academic hospitals. The prevalence of FTT, however, varies widely depending on the location of the physician's practice. In tertiary care settings, many patients with poor growth already have clearly recognized underlying organic diseases. When such underlying conditions are not readily apparent, aggressive evaluations in inpatient referral facilities have been reported to yield organic diagnoses in about half of the children investigated.