A thorough patient history, physical examination, and review
of past and present growth data are the first steps in the evaluation
of failure to thrive (see Table 30-3). Often,
the history will yield clues that may either direct further testing or
eliminate the need for extensive testing. The physician’s
role is to determine whether the child’s failure to thrive
is primarily due to insufficient caloric intake, energy wasting,
an increased caloric requirement, or altered growth potential. Dietary
assessment should include a 24-hour dietary recall and/or
completion of a 3-day food diary and observation of feeding when possible.
Global assessment of parent-child interactions should also be undertaken.
Clinical signs of protein-energy malnutrition may be present: loss
of skin turgor, little subcutaneous fat, lack of activity (apathy),
emaciation, sparse or lusterless hair, and poor nail growth. Additionally,
there may be skin hypopigmentation or hyperpigmentation, rash, and
edema. When needed, investigations should be selected
on the basis of patient history and physical examination rather
than ordered as a matter of routine. Laboratory tests not suggested
by the patient history and physical examination are rarely helpful.
A complete blood count, serum electrolytes, blood urea nitrogen,
creatinine, albumin, calcium, phosphorus, alkaline phosphatase,
urinalysis, and urine culture may assist in excluding systemic disease.
Other more specific tests sometimes employed in the evaluation are
shown in Table 30-4, and an algorithm is
provided in Figure 30-1.