A. Case study
B. More information
C. Editors' comments
E. CPD questions (South Africa)
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A. Case study
When a 10-month-old
boy was not gaining weight sufficiently, his mother took him to his
pediatrician. The child was born after a normal gestational period and
had a healthy birth weight. According to his growth curve, he had not
gained sufficient weight since about 4 months of age. He had only recently
been able to sit without support. He was thus somewhat behind in reaching
his milestones. His mother breastfed him from birth, but switched to
a cow's milk-based formula when her son was 3 months old, as she did
not want to breastfeed any longer. Except for the past 2 weeks, he had
drunk well. During these two weeks, he became less active, slept for
longer periods and appeared to tire while feeding.
What could be causing these symptoms? Could they be food-related? The
causes of such symptoms in children of this age may or may not be related
to food. To start, the pediatrician examined the child for all the obvious
possible causes of these symptoms, e.g., cardiac disease, infection,
etc. He did some routine tests, including urine and blood tests. The
child's temperature was not raised.
|When the doctor
received the test results, the white blood cell count was normal
and there were no signs of urinary tract infection. The only abnormality
was that the child had iron deficiency anemia. Although the symptoms
that the child was experiencing were some of the classical symptoms
of anemia, he had no clinical signs. The hemoglobin was not decreased,
but the MCV and MCHC were both decreased. This indicated that he
was in the earlier stages of anemia, and would explain why he had
no clinical signs.
What could be the cause of the anemia? Should a medical practitioner
in this case suggest iron-rich dietary sources and possibly a supplement?
Or should other possible causes be excluded first? There are in fact
many causes of iron deficiency anemia, which can be divided into the
a. Maternal iron deficiency during pregnancy
b. Insufficient dietary intake of iron due to inappropriate weaning
practices (most often the cause)
c. Blood losses through stools or urine
d. Insufficient iron absorption
e. Insufficient red blood cell hemoglobin manufacturing (the least likely
child's gestational age is an important factor to consider. Full-term
infants have a reserve of iron that is adequate to meet their requirements
for the first 4 to 6 months of life. In premature infants, the reserve
will probably last only for approximately 6 weeks, and extra intake
to prevent deficiency may be required. Because this child had a normal
gestational age, we can assume that he had sufficient iron reserves
until 4 to 6 months age. He had also received an iron-fortified formula
since the age of 3 months.
To determine the
cause of the anemia, the possibilities were investigated in the order
of the most likely to the least likely cause:
a. Maternal iron deficiency during pregnancy:
This was not thought to be a problem.
b. Insufficient dietary intake:
Infants of this age can present with iron deficiency anemia due to an
excessive intake of fluids such as unmodified milk, juice or tea. This
can result in a comparatively lower solid food intake. A diet history
revealed that the child had a sufficient dietary iron intake. He was
receiving an iron-fortified formula plus additional dietary sources.
c. Losses through stools or urine:
The child had no history of bleeding or gastrointestinal illness, and
the urine tests did not show any blood loss. The possibility of worm
infestation always needs to be excluded, especially in children who
often play outside or with pets. The child's stools did not show any
signs of worm infestation. But when an occult blood test was done, it
showed blood in his stools.
Chronic occult bleeding resulting in anemia can have many causes. The
most common ones are lesions in the gastrointestinal tract, and the
ingestion of cow's milk in susceptible individuals. These are thus the
possibilities that should be investigated first. Because the methods
for diagnosing gastrointestinal lesions are more time-consuming and
expensive than for diagnosing an adverse reaction to milk, it was decided
to explore a sensitivity to cow's milk first.
can be caused by severe milk allergy. Under the age of 1 year, however,
occult bleeding is more likely to be caused by the irritation of the
gastrointestinal lining by milk protein (a non-IgE reaction). This results
in chronic low-level bleeding, leading to anemia.
Is it worth doing a skin prick test or a serum-specific IgE test
to milk? There is a very good chance that it is a non-IgE-mediated
reaction, and the test results would thus be negative. This would
indicate only that it is not an IgE-mediated reaction. It would
be prudent to exclude milk from the diet and observe whether the
child's symptoms improve. By this method, both IgE and non-IgE-mediated
reactions can be identified. If milk is not the cause of the occult
bleeding, the symptoms would not improve with the exclusion of milk.
When the cow's milk formula was changed to a soya formula, the stools
were re-examined. No blood was present, which suggests that exposure
to cow's milk caused the occult blood loss, which in turn caused anemia.
It was thus not
necessary to investigate possibilities d or e (above) as potential causes
of the anemia.
The child was continued
on the soya formula and given an iron supplement for 3 months. After
a few weeks, the child's symptoms resolved completely.
|TIP for Allergy Advisor users:
When searching for "milk", one has the opportunity
to choose which type of milk (i.e., cow, mare, goat), which
milk product or which individual protein component (e.g.,
casein, caseinate, whey, etc.) of milk one would like more
information on. The "Adverse reactions" tab can
be selected to reveal the adverse reactions to cow's milk
that have been reported in the literature. They are divided
into "IgE & Immune reactions" and "Other