What was making boy lethargic and pale?

Part of the routine care of infants and young children is screening for iron deficiency anemia and lead poisoning at 9 to 12 months of age and then again at 18 to 24 months of age.

Both conditions are disturbingly common in Philadelphia, given the high rate of poverty - a key risk factor for anemia - and the many older homes that contain lead-based paint.

So it was no surprise recently when I found I had a year-old patient with anemia.

This little boy's hemoglobin was 9 (normal is 12). I contacted his mother and learned his diet included too much milk and not enough iron-rich foods, both common culprits in developing iron deficiency, the most common cause of anemia. I immediately prescribed iron medicine for him and scheduled a follow-up appointment in one month to repeat his labs and follow his growth and development.

I hung up the phone and started to review another child's lab result, which also showed iron deficiency anemia. This child's red blood cells were smaller than normal, which is typical of iron deficiency anemia. Yet the little boy I'd just treated had cells close to normal in size. Still, I knew this was common, and with a follow-up visit in a month, I was reassured that I'd made the right decision.

Two months later, the boy was back in my office. He had not gained much weight from his last visit, and he seemed pale and less energetic. The laboratory called me the next day: His hemoglobin had dropped to 5, less then half of normal, putting a strain on almost all of his organ systems trying to compensate for this degree of anemia.

I quickly contacted his mother. She assured me that she had given her son his iron every day, decreased his milk to two cups daily, and was feeding him more iron-rich foods.

"What now?" she asked, the fear apparent in her voice.

I told her to bring her son to our emergency room, where our pediatric hematologist would meet them.


Solution:

The hematologist obtained several other lab results and called me. The boy would need a blood transfusion and would have to be hospitalized for a day or two. The specialist added several more tests, including one to measure how fast red blood cells called reticulocytes are made by the bone marrow and released into the blood. Reticulocytes are in the blood for about two days before developing into mature red blood cells.

The more anemic you are, the higher your reticulocyte count should be. Yet this child's was less then 1 percent, when we would have expected it to be more than 5 percent.

Why wasn't his bone marrow doing its job?

TEC, or transient erythroblastopenia of childhood, was first described in 1970. It is one of the most common causes of decreased red blood cell production in young children. It's usually detected through routine screening, as with our patient, or when a parent notices a child seems tired and pale.

Why it occurs is still unknown, but there is usually a viral infection before children develop TEC. The anemia typically resolves in a month or two and usually does not recur.

After one transfusion of red blood cells, my little patient recovered nicely. On his last repeat blood test, he had a robust hemoglobin of 12 and was bouncing happily around the exam room, his rosy cheeks signaling his complete recovery.

Daniel R. Taylor, D.O., is an associate professor at Drexel University College of Medicine and director of community pediatrics and child advocacy at St. Christopher's Hospital for Children.