Anemias in children

Nomenclature and ICD-10 coding

In the International Classification of Diseases, this group of pathologies is classified under categories D50 to D64. For systematic memorization and clinical reasoning, all nosologies can be logically divided into several pathogenetic groups.

The first major group includes deficiency (nutritional) anemias. This encompasses conditions associated with iron deficiency (D50), vitamin B12 deficiency (D51), folic acid deficiency (D52), and deficiencies of other nutritional factors (D53).

The second group comprises hemolytic pathologies, which can be hereditary or acquired. These include disorders associated with impaired erythrocyte enzyme systems (D55) and various hemoglobinopathies, including thalassemia (D56) and sickle cell disorders (D57). Other hereditary (D58) and acquired (D59) forms of hemolysis are coded separately.

The third category covers aplastic conditions: acquired pure red cell aplasia (D60) and other forms of aplastic anemia (D61).

The classification also distinguishes posthemorrhagic forms, specifically acute anemia due to blood loss (D62), and secondary processes developing against the background of various chronic diseases (D63).

Principles of diagnosis systematization

To establish the most accurate clinical diagnosis, a pediatrician must systematize the identified changes according to three main criteria.

1. Morphological criterion. Based on the evaluation of the nature of erythrocyte changes themselves (their size, degree of hemoglobin saturation, and other structural features).
2. Etiopathogenetic criterion. Determines the leading mechanism that led to the development of the pathological process (acute blood loss, impaired hematopoiesis, or pathologically increased red blood cell destruction).
3. Clinical criterion. Reflects the severity of the current condition, which is directly determined by the depth of the hemoglobin drop.

Laboratory evaluation of erythrocyte changes

This classification is a crucial key to differential diagnosis. It is based on evaluating erythrocyte morphology and bone marrow functional activity according to three main parameters.

By the degree of hemoglobin saturation (color index — CI):

• Hypochromic (CI < 0.86) — directly indicates a lack of substrate for Hb synthesis (most commonly referring to iron deficiency).
• Normochromic (CI = 0.86–1.05) — indicates normal cellular saturation.
• Hyperchromic (CI > 1.05) — is a characteristic sign of megaloblastic processes.

By erythrocyte size (diameter):

• Microcytic (diameter < 7 µm) — very frequently accompanies hypochromia in clinical practice.
• Normocytic (diameter 7–7.8 µm).
• Macrocytic (diameter > 7.8 µm) — indicates pronounced disruptions in erythroid cell division.

By bone marrow regenerative capacity (reticulocyte fraction):

• Hyporegenerative (< 1% reticulocytes) — indicates suppression of erythropoiesis or acute substrate deficiency.
• Normoregenerative (1–3% reticulocytes).
• Hyperregenerative (> 3% reticulocytes) — considered a reliable sign of active compensatory hematopoiesis, which is typical for pronounced hemolysis or a history of blood loss.

Etiopathogenetic mechanisms of development

Globally, based on the mechanism of development, all anemia conditions are divided into three large groups.

1. Due to acute blood loss These conditions are associated with a direct, physical reduction in the circulating blood volume and total red blood cell mass. As a result, acute posthemorrhagic anemias develop.

2. Due to impaired hemoglobin and/or erythrocyte production This group includes conditions in which the bone marrow physically cannot produce a sufficient number of mature cells. This process is subdivided into two mechanisms:

• Deficiency states: the body lacks "building material" (iron, protein, vitamin B12, folic acid, and other micronutrients are deficient).
• Suppression of hematopoiesis: structural or functional impairments arise within the bone marrow itself, leading to its hypoplasia or aplasia.

3. Due to hemolysis Anemias of this group arise as a result of premature and accelerated destruction of erythrocytes (hemolytic anemias). The pathology manifests when the rate of red blood cell destruction begins to exceed the compensatory capabilities of erythropoiesis.

Criteria for determining severity

Assessing the severity of the syndrome in patients is a strictly formalized process. It is based solely on one key laboratory parameter — the level of hemoglobin (Hb) in the circulating blood.

• Mild severity: diagnosed when the Hb level is above 90 g/L.
• Moderate severity: established when the Hb value drops into the range from 70 to 90 g/L.
• Severe severity: recorded when the Hb level critically decreases to less than 70 g/L.

Class and exam questions

What else to study on this topic

• Deficiency (nutritional) forms: features of iron, vitamin B12, and folic acid deficiency
• Hemolytic anemias: enzymopathies and hemoglobinopathies (thalassemia, sickle cell disorders)
• Aplastic conditions and acquired pure red cell aplasia
• Mechanisms of secondary anemia development in chronic diseases

Other topics in "Chapter 10. Diseases of the Blood and Blood-Forming Organs"

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