Synopsis
Recognise iron deficiency across infancy, childhood and adolescence, confirm it without mistaking inflammation or thalassaemia for deficiency, treat with a calculated elemental-iron regimen, and correct the nutritional or pathological cause while protecting growth and development.
- The common childhood pattern is tiredness, pallor, poor appetite, irritability, reduced concentration or pica with a microcytic, hypochromic blood count.
- First-line investigation is FBC with red-cell indices, ferritin and an inflammatory marker; interpret haemoglobin and MCV against age-specific laboratory ranges.
- A low ferritin is strong evidence of depleted stores, but normal or raised ferritin does not exclude deficiency during infection, inflammation or liver disease.
- Check the blood film and reticulocyte count when anaemia is marked, the pattern is atypical, another cytopenia exists or haemolysis and marrow disease remain possible.
- First-line treatment for confirmed uncomplicated deficiency is oral elemental iron, calculated from the elemental rather than salt content, alongside cause-directed dietary change.
- A practical UK paediatric treatment range is elemental iron 3 to 6 mg/kg/day in 2 to 3 divided doses, maximum 200 mg/day, adjusted to the preparation and local formulary.
- Expect reticulocyte response within about a week and a measurable haemoglobin rise over 2 to 4 weeks; absence of response is a diagnostic checkpoint, not a reason to escalate blindly.
- Continue treatment after haemoglobin normalises long enough to replenish stores, commonly about three further months, then confirm recovery according to local paediatric guidance.
- Do not prescribe iron for isolated microcytosis until deficiency is demonstrated; thalassaemia trait is common and unnecessary iron can be harmful.
- Cow's milk should not be the main drink before 12 months; from around 6 months introduce varied iron-containing complementary foods in an age-appropriate texture.
Key red flags
Tachycardia at rest, gallop rhythm, syncope, breathlessness, chest pain, heart failure or haemodynamic compromise suggests anaemia severe enough for same-day hospital assessment.
Weight loss, persistent diarrhoea, blood in stool, abdominal pain or poor linear growth suggests gastrointestinal loss, coeliac disease or inflammatory bowel disease rather than diet alone.
Heavy menstrual bleeding, epistaxis, easy bruising or bleeding after procedures requires assessment of haemostatic as well as iron status.
Hepatosplenomegaly, lymphadenopathy, bone pain, recurrent fever, bruising or more than one cytopenia raises concern for malignancy, haemolysis or marrow failure.
A very young infant, prematurity, faltering growth, restricted diet, food insecurity, developmental regression or pica needs nutritional, developmental and safeguarding context assessed explicitly.
Failure of haemoglobin to rise despite a verified dose and adherence should prompt review of diagnosis, ongoing loss, malabsorption, inflammation, formulation and administration.
Investigation priorities
Confirm anaemia, identify microcytosis and detect another affected blood-cell lineage.
Assess iron stores while identifying inflammation that can falsely elevate ferritin.
Management branches
The child is clinically stable with compatible indices and depleted ferritin.
- Calculate and prescribe elemental iron from the chosen formulation and the child's current weight.
- Give tailored food and milk advice and address menstruation or another identified source of loss.
- Review tolerance, adherence, reticulocyte or haemoglobin response and safety within 2 to 4 weeks.
- Continue after haemoglobin recovery to replenish stores and confirm sustained correction.