[Iron deficiency anemia is not always simple].

Background: Malabsorption of oraliron is rare, and more frequently suspected than proved. It could be due to prolonged iron deficiency.

Case reports: Case no. 1: A boy was admitted at the age of 5 months for recurrent bronchitis. His hemoglobin was 8.2 g/dl, mean corpuscular volume (MCV) 60 micron3, mean corpuscular hemoglobin (MCH) 15 ng and mean corpuscular hemoglobin concentration (MCHC) 25 gHb/dl. The serum iron was 1 microgram/dl, iron binding capacity (IBC) was 284 micrograms/dl and ferritin was 14.9 ng/ml. Dietary iron was inadequate. The patient was given ferrous sulfate but iron deficiency persisted at the ages of 11 months and 3 years, probably due to poor compliance. Similar hematologic data (Hb: 6.4 g/dl, MCV 55 micrograms/m3, MCH 13.9 ng, MCHC 24 gHb/dl) were found at the age of 9 years. The patient was then given ferrous sulfate orally as test but the serum iron levels were unchanged during the 4 hours following ingestion. A parenteral iron preparation (iron-dextran, 500 mg) improved the hematologic data. 6 months later, a new oral test with ferrous sulfate improved the serum iron level. Case no. 2: A boy with complex congenital cardiopathy was operated on in the neonatal period and given oral iron at the age of 9 months because of anemia with microcytosis and hypochromia. This anemia was still present at 17 months and was associated with normal or high serum ferritin. Electrophoresis of hemoglobin was normal. At the age of 4 yr 5 mo, Hb was 9.7 g/dl, MCV 62.8 micrograms/m3, MCH 18.4 ng, iron 16 micrograms/dl and ferritin 94.1 ng/ml. An oral test with ferrous sulfate failed to increase the serum iron. The patient was then given parenteral iron-dextran without benefit, and a second oral test remained ineffective. After a second course of parenteral iron-dextran, Hb was 11.5 g/dl, MCV 74.1 micrograms/m3, MCH 23.7 ng while the serum iron remained low (23 micrograms/dl) and ferritin increased to 587 ng/ml. A third oral test with ferrous sulfate was still ineffective, as was a test using 4 mg/kg iron.

Conclusion: The first patient suffered from iron malabsorption, presumably due to iron deficiency. The second patient could have abnormal metabolism and/or abnormal ferritin.