What causes kwashiorkor in the body

Overview

Kwashiorkor is a serious nutritional disorder that predominantly affects infants and young children in developing countries. The term 'kwashiorkor' originates from the Ga language of Ghana and translates roughly to 'the sickness the baby gets when the next baby comes,' highlighting its association with the practice of early weaning. It is a form of severe protein-energy malnutrition (PEM), distinguished by specific clinical signs, most notably edema. While often discussed alongside marasmus (another form of PEM), kwashiorkor specifically points to a dietary imbalance where protein intake is critically low relative to overall calorie intake.

The underlying cause of kwashiorkor is a deficiency in dietary protein. This typically arises when a child is weaned from breast milk, which is rich in protein, and subsequently fed a starchy diet that is high in carbohydrates but very low in protein. This transition often occurs when a mother becomes pregnant again, and the older child is then given the family's staple foods, which may consist mainly of grains like rice or maize. While these foods provide energy, they lack the essential amino acids required for proper growth and bodily functions.

What is Kwashiorkor?

Kwashiorkor is a chronic malnutrition condition that develops due to a severe lack of protein in the diet. It is a distinct form of protein-energy malnutrition (PEM). The World Health Organization (WHO) classifies it under the broader category of 'wasting and stunting,' but its specific presentation makes it identifiable. Unlike marasmus, where there is a general deficiency of both calories and protein, kwashiorkor is characterized by a relative deficiency of protein, leading to a unique set of symptoms.

Causes and Risk Factors

The primary cause of kwashiorkor is an insufficient intake of protein. This can be due to several factors:

• Dietary Habits: The most common scenario involves children being weaned from breast milk and then fed a diet primarily composed of carbohydrates, such as cassava, rice, or maize, with very little protein-rich food like meat, fish, eggs, or legumes.
• Food Insecurity: In regions experiencing famine, poverty, or conflict, access to a balanced diet is compromised. Staple foods that are readily available and affordable are often carbohydrate-heavy and protein-poor.
• Inadequate Knowledge of Nutrition: Sometimes, even when protein sources are available, a lack of nutritional education can lead to poor dietary choices within a family.
• Infections and Illnesses: Chronic infections, parasitic infestations, or illnesses can increase the body's protein requirements and impair nutrient absorption, exacerbating protein deficiency. Conditions like diarrhea, measles, and tuberculosis are common culprits.
• Rapid Growth Periods: Infants and young children are particularly vulnerable because they are in periods of rapid growth, which demands a higher protein intake relative to their body weight.

Pathophysiology: How Protein Deficiency Leads to Symptoms

The severe protein deficiency in kwashiorkor disrupts several critical bodily functions:

• Edema (Swelling): Proteins, particularly albumin, play a crucial role in maintaining oncotic pressure in the blood vessels. This pressure helps to keep fluid within the bloodstream. When protein levels drop significantly, fluid leaks out of the blood vessels into the surrounding tissues, causing swelling, most noticeably in the abdomen (ascites), legs, and face.
• Impaired Immune Function: Proteins are essential for producing antibodies and maintaining immune cells. Protein deficiency weakens the immune system, making individuals highly susceptible to infections.
• Skin and Hair Changes: Proteins are vital for cell growth and repair. Their deficiency can lead to dry, flaky skin, skin lesions, and changes in hair color (depigmentation, turning reddish or blond), texture (thin, brittle), and loss.
• Muscle Wasting: While not as pronounced as in marasmus, muscle mass is still lost as the body breaks down muscle tissue to obtain essential amino acids for vital functions.
• Growth Retardation: Protein is the building block for growth. Insufficient protein intake severely stunts physical and cognitive development.
• Fatty Liver: The liver plays a role in synthesizing lipoproteins, which transport fats from the liver to other parts of the body. Severe protein deficiency impairs this process, leading to fat accumulation in the liver cells.

Clinical Manifestations (Symptoms)

The signs and symptoms of kwashiorkor are distinctive:

• Edema: This is the hallmark symptom, presenting as generalized swelling, particularly in the legs, feet, face, and abdomen.
• Muscle Wasting: Although masked by edema, underlying muscle loss is present.
• Growth Failure: Children are significantly shorter and lighter than their peers.
• Behavioral Changes: Irritability, apathy, and lethargy are common.
• Hair Changes: Hair may become depigmented (lighter in color), thin, brittle, and fall out easily. It may also have a characteristic 'flag sign' appearance, with alternating bands of pale and dark hair, reflecting periods of malnutrition and recovery.
• Skin Lesions: Skin can become dry, flaky, and develop sores or ulcers, especially in areas prone to friction.
• Enlarged Liver (Hepatomegaly): The liver may be enlarged due to fatty infiltration.
• Increased Susceptibility to Infections: Frequent and severe infections are common.

Diagnosis

Diagnosis is primarily clinical, based on the characteristic symptoms, especially edema, in a child with a history suggestive of protein-deficient diet. Anthropometric measurements (height, weight, mid-upper arm circumference) are used to assess the severity of malnutrition. Blood tests may be performed to assess protein levels (serum albumin), electrolytes, and rule out other conditions.

Treatment and Management

Treatment of kwashiorkor requires careful medical management to avoid complications:

• Rehydration and Electrolyte Balance: Initial management focuses on correcting dehydration and electrolyte imbalances, which can be life-threatening.
• Gradual Nutritional Rehabilitation: This is a multi-stage process. The child is first given a low-protein, low-lactose diet to allow the gut to recover. Once stable, the diet is gradually advanced to include complex carbohydrates, followed by moderate amounts of protein and essential fats. Specialized therapeutic foods (like Plumpy'Nut) are often used.
• Management of Infections: Any underlying or concurrent infections must be treated promptly with appropriate antibiotics or antiviral medications.
• Micronutrient Supplementation: Vitamins and minerals are often supplemented to address deficiencies.
• Psychosocial Support: Affected children and their families often require counseling and support.

Recovery can be slow, and long-term consequences such as stunted growth and cognitive deficits may persist if malnutrition was severe or prolonged.

Prevention

Prevention is key and involves:

• Promoting and supporting breastfeeding for the first six months of life.
• Educating mothers and caregivers about balanced nutrition and appropriate complementary feeding practices after six months.
• Addressing poverty and food insecurity to ensure access to diverse and nutritious foods.
• Improving access to healthcare to manage childhood illnesses effectively.

Kwashiorkor remains a significant public health challenge in many parts of the world, underscoring the critical importance of adequate protein intake for healthy child development.