Iron Deficient Anemia: A Comprehensive Guide

 Iron deficiency anemia (IDA) – a comprehensive review

 

Iron deficiency anemia (IDA) is the most common form of anemia worldwide. It occurs when the body lacks enough iron to produce hemoglobin, the protein in red blood cells that is responsible for transporting oxygen. IDA affects all age groups and can lead to significant morbidity if left untreated. In this detailed discussion, we will review the etiopathogenesis, clinical features, management, and prevention of iron deficiency anemia.

 

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1. Etiopathogenesis of Iron Deficiency Anemia

 

Iron deficiency anemia results from an imbalance between the body’s iron needs and available supply. This imbalance can be caused by:

 

1. Iron deficiency

– Inadequate dietary intake: Iron deficiency is particularly common in populations with limited access to iron-rich foods or those who eat a predominantly plant-based diet. Non-heme iron (from plant sources) is less bioavailable than heme iron (from animal sources).

– Nutrition: Lack of varied, nutritious food sources leads to low iron intake.

 

1. Increased Iron Requirements

– Growth Periods: Infants, children and adolescents have a high demand for iron due to rapid growth and massive red cell proliferation.

– Pregnancy: During pregnancy, a woman’s iron needs increase significantly due to anemia, growth of the fetus, and anemia at birth.

– Menstruation: Women of childbearing age are at risk of IDA due to anemia during menstruation.

 

1. Malabsorption of Iron

– Gastrointestinal disorders: Conditions such as celiac disease, inflammatory bowel disease (Crohn’s disease, ulcerative colitis) and atrophic gastritis affect iron absorption.

– Post-Surgical Malabsorption: Bariatric surgery, especially procedures that bypass portions of the duodenum (primary site of iron absorption), can lead to iron deficiency.

– Helicobacter pylori infection: This can cause chronic gastritis and malabsorption of iron.

 

1. Increased iron deficiency

– Chronic Anemia:

 – Gastrointestinal bleeding: from peptic ulcer, esophageal disease, hemorrhoids, colorectal cancer, or angiodysplasia.

 – Menorrhagia: Heavy menstrual bleeding is a common cause of iron deficiency in women.

 – Repeated blood donation: Regular blood donors may develop iron deficiency if iron stores are not adequately replenished.

 

1. Intravascular Hemolysis

Conditions that cause hemolysis (eg, hemoglobinuria) can cause urinary iron loss. This is rare but can lead to iron deficiency in certain chronic conditions such as paroxysmal nocturnal haemoglobinuria.

 

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2. Clinical Features of Iron Deficiency Anemia

 

The clinical presentation of IDA depends on the severity and duration of the deficiency. Common signs and symptoms include:

 

1. General Symptoms

– Fatigue: Decreased oxygen delivery to tissues causes fatigue and weakness, which are frequent complaints.

– Jaundice: Yellowing of the skin and mucous membranes (eg conjunctiva) due to decreased hemoglobin levels.

– Exertional Dyspnea: Decreased oxygen carrying capacity leads to shortness of breath during physical activity.

– Rapidity: Increased heart rate to compensate for low oxygen supply.

 

1. Neurological Symptoms

– Restless Legs Syndrome: A tingling or crawling sensation in the legs, especially at night, is associated with iron deficiency.

– Pica: Cravings for non-nutritive foods such as ice (pagophagia), dirt, or starch are often observed in patients with iron deficiency.

 

1. Specific Symptoms of Iron Deficiency

– Koilonychia: Spoon-shaped nails, a classic but uncommon finding in chronic iron deficiency.

– Glossitis: Inflammation of the tongue, resulting in pain and tenderness.

– Angular cheilitis: cracks and fissures in the corners of the mouth.

– Blue sclera: Thinning of the sclera can make the underlying choroid appear blue.

 

1. Severe or Chronic Iron Deficiency

In cases of prolonged iron deficiency, the body’s adaptive mechanisms can no longer compensate, leading to severe symptoms such as:

– Heart Failure: Chronic anemia can cause left ventricular hypertrophy and eventually heart failure.

– Impaired cognitive and immune function: Iron is essential for brain and immune cell function, leading to cognitive impairment and increased susceptibility to infections in iron-deficient individuals.

 

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3. Management of iron deficiency anemia

 

1. Diagnosis

The diagnosis of IDA is based on a combination of clinical history, physical examination, and laboratory investigations.

1. LABORATORY RESULTS

– Complete Blood Count (CBC): reveals microcytic, hypochromic anemia (low mean corpuscular volume [MCV] and mean corpuscular hemoglobin [MCH]).

– Serum Ferritin: The most sensitive test for iron deficiency. Low ferritin indicates depleted iron stores.

– Serum Iron and Total Iron Binding Capacity (TIBC): Low serum iron with elevated TIBC indicates iron deficiency.

– Peripheral blood smear: shows microcytosis, hypochromia, and possibly target cells and pencil cells.

– Reticulocyte count: Often low or normal in iron deficiency due to insufficient iron for red blood cell production.

 

2. Root Cause

Investigation of the underlying cause of iron deficiency is critical, particularly in adult men and postmenopausal women where chronic anemia (eg, gastrointestinal bleeding) must be ruled out.

 

1. Treatment

 

1. Oral Iron Therapy

– First-line treatment: Oral iron supplements (ferrous sulfate, ferrous fumarate, or ferrous gluconate) are the initial treatment for most patients.

– DOSE: Usually 100-200 mg of elemental iron per day.

– Duration: Continued for 3-6 months to replenish iron stores after hemoglobin normalization.

– SIDE EFFECTS: Gastrointestinal side effects (nausea, constipation, diarrhea) are common and may require dose adjustment or switching to a different formulation.

– Increase absorption: Vitamin C (ascorbic acid) can increase iron absorption. Avoid taking iron with calcium, tea or coffee, which inhibits absorption.

 

2. Parenteral Iron Therapy

– Indications: For patients who cannot tolerate oral iron or are malnourished (eg, celiac disease or after bariatric surgery), or with severe anemia requiring rapid correction. is required.

– Iron formulations: intravenous iron sucrose, ferric carboxymaltose, or iron dextran are commonly used.

– Monitoring: Monitor for hypersensitivity reactions, especially with older formulations such as iron dextran.

 

3. Blood Transfusion

– Indications: Symptomatic, reserved for patients with severe anemia (eg, hemoglobin <7-8 g/dL) or in cases where rapid correction is necessary (eg, severe bleeding).

– Caution: Over-reliance on transfusions may lead to iron overload or alloimmunization.

 

1. Follow Up

– Response to treatment: The reticulocyte count should rise within 7-10 days, followed by an increase in hemoglobin after 2-4 weeks.

– IRON LEVEL MONITORING: Ensure that ferritin levels normalize after hemoglobin correction to avoid relapse.

 

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4. Prevention of iron deficiency anemia

 

1. Dietary Measures

– IRON RICH FOODS: Encourage consumption of iron rich sources (meat, poultry, fish) and iron rich foods.

– Improve Iron Absorption: Consume vitamin C-rich foods (eg citrus fruits) with iron-rich foods to improve non-heme iron absorption.

– Avoid Inhibitors: Limit consumption of tea, coffee and calcium-rich foods during meals as they reduce iron absorption.

 

1. Iron Supplementation

– Prophylactic Iron: In high-risk groups (eg, pregnant women, infants), routine iron supplementation may be recommended.

– Pregnancy: The World Health Organization (WHO) recommends 30-60 mg of elemental iron per day for pregnant women.

 – Children: Breastfed infants should receive iron supplements at 4-6 months of age, especially in areas with high rates of iron deficiency.

 

1. Public Health Interventions

– Iron Fortification: Fortification of staple foods (eg flour, cereals) with iron has been shown to reduce the prevalence of iron deficiency in many populations.

– Education and Awareness: Public health campaigns can increase awareness of the importance of iron in the diet and help reduce the stigma associated with iron deficiency.

 

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Conclusion:

 

Iron deficiency anemia is a global health problem with important implications for both individuals and populations. Early recognition, appropriate diagnosis, and effective management are critical to prevent long-term complications. Addressing underlying causes, improving treatment, and implementing prevention strategies can help reduce the burden of IDA, particularly in vulnerable groups such as children, pregnant women, and the elderly.