The Case

He was a previously healthy child, no significant past medical history, and term birth. He was up to date on vaccinations and regularly follows up with his pediatrician. Mom states about a week ago he started developing fevers up to 102F at home with some associated coughing and runny nose. These symptoms mostly resolved a few days ago with no further fevers, but he seemed lethargic per the parents so they took him to the pediatrician yesterday and insisted on bloodwork. They got a callback today that his hemoglobin was 5 g/dL and he should come to the ER. The parents say he has been acting normally today, no fatigue, and no fevers. They say he has been having normal intake and normal elimination. No blood noted in his bowel movements. No family history of anemia or cancer.

On exam, he had normal vital signs. He was well appearing and interactive. He had pale mucous membranes, but no signs of infection noted, no hepato/splenomegaly, no rashes, n bruising, and no petechiae noted.

The Differential

Oncologic

Think about leukemia in children with other symptoms including easy bruising/bleeding, fevers of unknown origin, fatigue, nonspecific pain and petechiae. This child had no family history of cancers and his fevers seemed to be related to a URI and had resolved, mom reported no easy bruising, no abnormal bleeding, and no petechiae were seen on exam.

Iron Deficiency

Think about iron deficiency in children with inadequate dietary intake or with causes of chronic occult blood loss. Mom states he takes a multivitamin daily, they have no family history of inflammatory bowel disease. He does drink cow’s milk however, several times a day.

Genetic

There are many genetic causes of anemia in childhood: sickle cell, thalassemias, GDPD deficiency. Most newborn screens pick up these diseases but you can also inquire about family history. This child followed closely with his pediatrician, mom was not aware of anything positive on his newborn screen, she did know of a great uncle with some sort of thalassemia in the family but, no one else she can think of.

Hemolytic

Other causes to think about are hemolytic anemias including HUS, drug induced hemolysis, and DIC. This child’s infectious symptoms had resolved at this point and he had no reported episodes of diarrhea. He also had no rashes on exam and mom reported no medications.

*HUS deserves some special mention as it is a frequently tested topic on boards: Consider this in patients with history of recent diarrheal illness (think E. coli O157:H7 or shigella). Has a triad of: hemolytic anemia, uremia, and thrombocytopenia. You see schistocytes on peripheral smear.

Infectious

One consideration for this child given his recent viral illness is transient erythroblastopenia of childhood. This is a transient immune reaction against progenitor cells usually seen after a toxin ingestion or viral illness. Think about this in children 6 months to 3 years of age.

Environmental

One major environmental consideration is lead poisoning. This is something to keep in mind for children living in a home built before 1970 or kids with pica. You may see them having abdominal pain or altered mental status if level is significant. Mom was not sure of the date their apartment was from, but stated he had just had lead testing done and results were normal.

Blood loss

Another differential to consider is blood loss, secondary to trauma vs bleeding. Evaluate for history or signs of trauma, particularly in a child with hemophilia. Ask about history of hematuria or GI bleeding.

The Work Up

Going through the differential, the two most likely causes were either post infectious or iron deficiency given his regular ingestion of cows milk. Leukemia was also considered, but we were assuming the rest of the CBC done at the doctors office was normal. Our plan was to obtain a repeat CBC as well as iron studies and discuss the case with hematology. Repeat CBC was notable for a hemoglobin of 5.4 and microcytic anemia but otherwise normal. Iron studies showed low iron level, low ferritin, high TIBC and transferrin. Hematology was called, they reviewed labs so far and took a look at a peripheral smear.

Case Conclusion

Hematology agreed with our differential and stated that the most likely cause in this case was iron deficiency anemia from cow’s milk ingestion. They stated the lab results and peripheral smear were classic for this diagnosis. They also added that an infectious cause was a good thought given his recent viral syndrome, but that usually appears as a normocytic anemia. They requested a reticulocyte count which was normal. They recommended discharging the patient home with iron supplementation and discontinuation of cow’s milk with follow up in 2 weeks for repeat hemoglobin. They stated that since the cause was iron deficiency and he was asymptomatic at this presentation, transfusion is not necessary. Hematology expects his hemoglobin will return to normal levels with discontinuation of cow’s milk and iron supplementation in 2 weeks at his follow up visit.

Anemia is an uncommon pediatric presentation in emergency medicine, but an important topic to discuss as it has a broad differential which includes potentially life threatening conditions. Normal hemoglobin levels differ based on age (like most things in pediatrics). A simplified table of values for hemoglobin is below:

Age	Hemoglobin Level
Birth	16.5 g/dL
1 week	17.5 g/dL
1 month	14.0 g/dL
6mo to 2 years	12 g/dL
6-12 years	13.5 g/dL

Blood transfusion parameters in children over 4 months of age are similar to adult guidelines. Generally, we consider transfusion at hemoglobin levels between 7-10 g/dL in symptomatic patients and at hemoglobin levels less than 7 g/dL in asymptomatic patients. In our case, the decision not to transfuse was made in discussion with hematology. Furthermore, at CHOP their practice is not to transfuse asymptomatic anemia from iron deficiency

Ingestion of cow’s milk in infants under 1-2 years of age is a common cause of anemia. There have been several proposed mechanisms of this. Generally, the most recognized is that cow’s milk contains a lower iron content than breastmilk or formula. Another proposed cause is occult intestinal blood loss caused by ingestion of the cow’s milk – the larger protein molecules can cause microscopic bleeding. To avoid this, it is generally recommended to avoid giving cow’s milk to children under one year of age and to give limited quantities (16-24 oz depending on your resource) to children under 2 years of age.

Anemia in children is a broad topic with an interesting differential diagnosis. If you are interested in reading further, check out some of these FOAM links below:

Author: Alanna O’Connell – PGY3.   @AlannaOConnell8

FOAMed Resources

• Pediatric EM Morsels: Leukemia Clues
• Pediatric EM Morsels: Lead Poisoning
• Pediatric EM Morsels: Aplastic Anemia
• WikiEM: HUS
• EM:RAP C3 on Hematology Review

References

EE Zeigler. “Consumption of Cow’s Milk as a cause of Iron Deficiency Anemia in Infants and Toddlers”. Nutr Rev. 2011 Nov; 69 Suppl 1:S37

J Janus, S Moerschel. “Evaluation of Anemia in Children”. American Family Physician. 2010 Jun 15; 81(12): 1462-1471

J Teruya. “Red Blood Cell Transfusions in Infants and Children: Indications”. Up To Date. 2016 Oct. https://www.uptodate.com/contents/red-blood-cell-transfusion-in-infants-and-children-indications

Hemoglobin Concentration. Medscape. http://emedicine.medscape.com/article/2085614-overview