epidemiology and clinical manifestations of iron deficiency anemia in children

Iron deficiency anemia (IDA) remains the most common nutritional disorder worldwide, representing a major public health challenge across both developed and developing nations. Epidemiologically, it affects an estimated two billion people globally, with the highest burden observed among women of reproductive age, infants, young children, and adolescents due to increased physiological demands. Pregnant women are particularly vulnerable, with prevalence rates exceeding ۴۰% in some regions, contributing significantly to maternal morbidity and adverse pregnancy outcomes. Socioeconomic disparities, poor dietary intake, chronic blood loss, parasitic infections, and limited access to healthcare services further amplify the global burden. Although IDA is prevalent in low-income countries, it also persists in high-income settings where dietary patterns, heavy menstrual bleeding, gastrointestinal blood loss, or chronic diseases contribute to iron depletion. Clinically, IDA develops insidiously, with symptoms and signs reflecting impaired oxygen delivery to tissues. The most common presenting symptoms include fatigue, generalized weakness, pallor, and reduced exercise tolerance. Cognitive impairment, poor concentration, irritability, and impaired school or work performance are frequently noted, especially in children and adolescents. Dyspnea on exertion, palpitations, and headaches are reported in more advanced cases. Distinctive but less common features include pica (craving for non-nutritive substances such as ice or soil) and restless legs syndrome. Physical signs are variable and often subtle. Pallor of the skin and conjunctiva is the hallmark clinical finding. Additional manifestations include brittle or spoon-shaped nails (koilonychia), angular cheilitis, atrophic glossitis, and dry, thinning hair, all reflecting chronicity of the deficiency. In severe or prolonged cases, tachycardia, systolic murmurs, or signs of heart failure may be observed due to compensatory cardiovascular strain. Importantly, the severity of symptoms often correlates with both the degree and rapidity of hemoglobin decline. In conclusion, iron deficiency anemia is a widespread, preventable condition with substantial health, developmental, and economic consequences. Recognition of its epidemiological determinants and classical constellation of symptoms and signs is essential for early diagnosis, timely treatment, and implementation of effective preventive strategies.