Approach to growth faltering: Clinical sciences

Growth faltering refers to the inability to gain or maintain adequate weight as a consequence of malnutrition. Growth faltering is most frequently caused by insufficient caloric intake, but it can also result from an underlying condition that’s associated with increased metabolic requirements or malabsorption.

When a pediatric patient presents with growth faltering, you should first obtain measurements of weight and height or length; and plot the results on a standardized growth chart.

Next, review the growth parameters. If your patient’s weight-for-age or BMI is more than 2 standard deviations below the mean for age and biological sex on multiple occasions; or if their weight-for-age has crossed 2 major percentile lines; your patient’s growth is faltering.

Here’s a clinical pearl! In some circumstances, a low or decelerating weight-for-age represents a normal variant of growth. For example, preterm infants whose growth parameters haven’t been adjusted for gestational age may appear to have insufficient weight gain.

Conversely, infants born large for gestational age experience catch-down growth in the first 6 months of life, and may appear to have faltering growth while their weight is regressing to their expected growth trajectory. Finally, a child with familial short stature may have a consistently low but appropriate weight-for-age. When in doubt, check your patient’s weight-for-length or weight velocity, to determine whether a low weight-for-age requires further evaluation.

Now that you’ve identified growth faltering, your next step is to obtain a focused history and physical exam. Be sure to ask whether your patient has a chronic health condition, a history of frequent infections, or a significant developmental delay. Additionally, find out if your patient has had frequent vomiting or an abnormal stooling pattern.

When it comes to the physical exam, some signs to look out for include characteristic facial features that suggest a genetic condition, as well as abnormal cardiac findings, hepatosplenomegaly, and lymphadenopathy. Next, assess for the presence of an underlying health condition.

First, let’s discuss health conditions that are associated with excessive energy expenditure. History might reveal genetic conditions; inborn errors of metabolism; immunodeficiencies; hyperthyroidism; anemia; or chronic cardiac, pulmonary, liver, or renal disease. If your patient has a chronic health condition that increases energy expenditure, this is probably contributing to their faltering growth.

Here’s another clinical pearl! In some cases, faltering growth could be related to an unrecognized condition, so use clues from the history and exam to focus your diagnostic evaluation. For example, if your patient has developmental delay, hypotonia, or characteristic facial features, consider ordering genetic studies to look for mutations or microdeletions. For those with symptoms suggesting hyperthyroidism, order a TSH and free T4. If the exam reveals pallor, a CBC may reveal low hemoglobin; and if you suspect liver or renal disease, a CMP might demonstrate elevated transaminases or creatinine.
Finally, you can obtain a chest X-ray to look for pulmonary disease and consider an echocardiogram if you suspect structural heart disease.

Let’s move on and discuss patients whose history and exam findings do not suggest a condition that increases energy expenditure. In this case, you should assess your patient’s stooling pattern and consistency.

Some patients may report constipation; diarrhea; or steatorrhea, which is a term that describes bulky, greasy, foul-smelling stools. In this case, consider conditions associated with malabsorption, like celiac disease and cystic fibrosis.

Next, order labs, including a tissue transglutaminase IgA, or anti-tTG IgA; a total IgA; and a fecal elastase level. Also, consider ordering a sweat chloride test, especially if your patient has had recurrent respiratory infections.

Now, a positive anti-tTG IgA and normal total IgA are highly suggestive of celiac disease, which you can confirm with endoscopy and duodenal biopsy.

Even though celiac disease can present with anemia, abdominal distension, and rash; in some cases, poor weight gain is the only manifestation.

On the flip side, a low fecal elastase in combination with an elevated sweat chloride is consistent with cystic fibrosis. In this condition, pancreatic insufficiency leads to steatorrhea and malabsorption.

Here’s another clinical pearl! Shwachman Diamond syndrome is another genetic condition that is associated with pancreatic insufficiency and malabsorption. Children with this syndrome often have skeletal abnormalities and experience frequent infections and bone marrow failure. Additionally, intestinal infection from Entamoeba histolytica is a rare cause of malabsorption and poor weight gain. Affected patients typically develop abdominal pain, bloody diarrhea, and fever after traveling to a tropical location.

Alright, let’s switch gears and discuss patients who describe a normal stooling pattern and consistency. In this case, consider causes related to inadequate caloric intake, so assess for upper gastrointestinal losses.

If your patient reports vomiting or regurgitation, think of pyloric stenosis and gastroesophageal reflux disease (GERD). (??)