What is protein energy malnutrition called? Common names and classifications

Protein-energy malnutrition (PEM) is a serious and widespread condition, particularly affecting children in developing nations, with estimates indicating it accounts for a significant number of annual deaths. But the term PEM is a broad category, and this condition is referred to by several more specific names, depending on its clinical presentation and the primary nutritional deficiency involved.

Quick Summary

Protein-energy malnutrition (PEM) is also known as protein-energy undernutrition (PEU), protein-calorie malnutrition (PCM), and includes specific forms like Kwashiorkor and Marasmus. These names classify deficiencies in protein, calories, or a combination of both.

Key Points

• Protein-Energy Malnutrition (PEM) is a broad term: The condition is also known as Protein-Energy Undernutrition (PEU) or Protein-Calorie Malnutrition (PCM).

• Kwashiorkor is protein-deficient PEM: This form is primarily caused by a lack of protein, often in the presence of adequate calories, and is characterized by edema (swelling).

• Marasmus is calorie-deficient PEM: This is the result of a severe deficiency of both protein and calories, leading to extreme emaciation and wasting without edema.

• Marasmic Kwashiorkor is a mixed form: The most severe type, it presents with both the wasting of Marasmus and the edema of Kwashiorkor.

• Diagnosis depends on physical signs and lab tests: Doctors can identify PEM through visual examination, anthropometric measurements, and blood tests for albumin and electrolytes.

• Treatment requires careful refeeding: Correcting life-threatening imbalances and gradually reintroducing nutrients is critical to avoid complications like refeeding syndrome.

Introduction to Protein Energy Malnutrition (PEM)

Protein-energy malnutrition (PEM), sometimes also called protein-energy undernutrition (PEU), is a severe form of malnutrition caused by a lack of dietary protein and energy (calories). The specific names used to describe the condition depend on which macronutrient is predominantly deficient. This spectrum of conditions can have profound and devastating effects on an individual’s growth, development, and overall health, especially in children. The clinical picture can range from mild deficiency to life-threatening emaciation or edema.

The Two Primary Clinical Names for Severe PEM

When answering the question, "What is protein energy malnutrition called?", two distinct and severe syndromes come to mind: Kwashiorkor and Marasmus. These represent the classic clinical presentations of severe PEM, with a third, Marasmic Kwashiorkor, showing characteristics of both.

Kwashiorkor (Wet PEM)

Kwashiorkor is the form of severe PEM where the protein deficiency is more pronounced than the calorie deficiency. The name originates from the Ga language of Ghana, meaning "the sickness the baby gets when the new baby comes," referring to a toddler who is weaned from protein-rich breast milk and given a carbohydrate-heavy diet.

Key features of Kwashiorkor:

• Edema: The most distinguishing sign is fluid retention, which causes swelling, particularly in the ankles, feet, hands, and face. This can also lead to a characteristic bloated or distended belly.
• Skin and hair changes: Skin can become dry, hyperpigmented, and peel, described as having a "flaky paint" dermatosis. Hair may become thin, brittle, and discolored, often with a reddish or grayish tinge.
• Apathy and fatigue: Children often appear lethargic, apathetic, and irritable.
• Enlarged liver: A fatty liver, or hepatomegaly, is a common complication.

Marasmus (Dry PEM)

Marasmus, in contrast, results from a severe deficiency of both calories and protein. Individuals with Marasmus do not have the edema seen in Kwashiorkor and instead present with severe wasting and an emaciated appearance.

Key features of Marasmus:

• Visible wasting: There is a significant loss of body fat and muscle, making bones visibly prominent through the skin. This gives the appearance of being shriveled and wizened.
• Growth retardation: Children with Marasmus experience stunted growth.
• Extreme weakness: Sufferers exhibit lethargy, extreme weakness, and low body weight.
• Loose skin: The severe loss of subcutaneous fat results in loose, wrinkled skin that hangs in folds.

Marasmic Kwashiorkor

This is a mixed form of severe PEM, demonstrating symptoms of both conditions. The patient exhibits the severe wasting of Marasmus along with the edema of Kwashiorkor. This is often considered the most severe manifestation of PEM.

Comparison of Kwashiorkor vs. Marasmus

Feature	Kwashiorkor	Marasmus
Primary Deficiency	Predominantly protein deficiency, with adequate calorie intake	Deficiency of both protein and total calories
Appearance	Edema (swelling), bloated abdomen, sometimes called "wet" PEM	Severe emaciation, muscle wasting, known as "dry" PEM
Distinguishing Sign	Peripheral edema (fluid retention)	Absence of edema; loose, hanging skin folds
Fat and Muscle	Subcutaneous fat and muscle are depleted but retained relative to body weight	Severe depletion of both fat and muscle tissue
Liver	Often has an enlarged, fatty liver	Liver size is typically normal or atrophied

Additional Terminology for PEM

Besides the clinical syndromes, other terms are used in a medical context to describe protein-energy malnutrition, reflecting a broader view of undernutrition.

• Protein-Energy Undernutrition (PEU): A more modern term that encompasses the full spectrum of conditions arising from a lack of dietary protein and energy.
• Protein-Calorie Malnutrition (PCM): An older term that is used interchangeably with PEM, reflecting the dual deficiency of both protein and calories.
• Starvation: An acute, severe form of primary PEM resulting from a complete lack of nutrients.

Causes, Diagnosis, and Treatment

What Causes PEM?

• Inadequate food intake: The primary cause worldwide, especially in children and the elderly in resource-poor areas.
• Infectious diseases: Conditions like chronic diarrhea, measles, or HIV can increase metabolic demands and decrease appetite, often precipitating PEM.
• Underlying medical conditions: In developed nations, PEM is more often a complication of other diseases such as chronic renal failure, cancer, or anorexia nervosa.
• Weaning practices: In some cultures, infants are abruptly weaned from breast milk to low-protein, high-carbohydrate foods, triggering Kwashiorkor.

How is PEM Diagnosed?

Diagnosis relies on a combination of physical examination, clinical history, and laboratory tests.

Common diagnostic criteria and tests:

1. Physical signs: Observance of edema, wasting, skin and hair changes, and apathy.
2. Anthropometric measurements: Checking a person's weight-for-height, mid-upper arm circumference, and BMI against standard charts.
3. Laboratory tests: Blood tests can reveal low serum albumin levels, electrolyte imbalances, and micronutrient deficiencies (like zinc), which are common with PEM.

How is PEM Treated?

Treatment requires careful management, often starting with inpatient care for severe cases due to the risk of refeeding syndrome—a potentially fatal shift in fluid and electrolytes.

Treatment phases include:

1. Initial stabilization: Correcting life-threatening conditions like hypoglycemia, hypothermia, dehydration, and infections.
2. Nutritional rehabilitation: Gradual reintroduction of a balanced diet, carefully increasing protein and calories to support catch-up growth.
3. Follow-up care: Long-term support and nutritional education to prevent relapse.

Conclusion: Naming the Disease to Understand It

Protein-energy malnutrition (PEM) is a serious, multifaceted health issue. While the acronym PEM provides a general category, the specific names—Kwashiorkor and Marasmus—are crucial for distinguishing the clinical presentation and tailoring appropriate treatment. Kwashiorkor is primarily a protein deficiency marked by edema, whereas Marasmus is a combined calorie and protein deficiency characterized by severe wasting. Recognizing these distinctions, as well as the broader terms like PEU and PCM, is vital for accurate diagnosis and effective nutritional intervention. Early detection and management are key to preventing long-term physical and cognitive damage, especially in vulnerable populations. For more in-depth medical information on PEM, the MSD Manuals provide comprehensive details on the topic.

References

• Kwashiorkor: Definition, Symptoms, Causes & Diagnosis. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/23099-kwashiorkor
• Marasmus: Definition, Symptoms & Causes - Cleveland Clinic. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/23296-marasmus
• Protein–energy malnutrition - Wikipedia. Wikipedia. https://en.wikipedia.org/wiki/Protein%E2%80%93energy_malnutrition
• Protein-Energy Malnutrition - Medscape Reference. Medscape. https://emedicine.medscape.com/article/1104623-overview
• Protein–Energy Malnutrition - AccessMedicine. McGraw-Hill Medical. https://accessmedicine.mhmedical.com/content.aspx?bookid=3343&sectionid=279777421
• Protein-Energy Undernutrition (PEU) - Nutritional Disorders. MSD Manuals. https://www.msdmanuals.com/professional/nutritional-disorders/undernutrition/protein-energy-undernutrition-peu

Frequently Asked Questions

What is the primary difference between Kwashiorkor and Marasmus?

The primary difference lies in the main nutrient deficiency and the resulting physical signs. Kwashiorkor is a protein deficiency that causes edema (fluid retention), while Marasmus is a deficiency of both protein and calories, leading to severe emaciation and wasting without edema.

Is protein-energy malnutrition (PEM) common today?

While the rates have generally decreased, PEM remains a significant global health problem, particularly in developing countries. In industrialized nations, it is more commonly seen in hospital settings or among the elderly and those with chronic diseases.

What are the common causes of PEM?

The most common cause is an inadequate intake of food due to poverty or food scarcity. Other factors include infectious diseases that increase nutrient needs, ineffective weaning practices in infants, and underlying medical conditions that affect nutrient absorption.

How is Kwashiorkor treated?

Treatment for Kwashiorkor is a multi-stage process. Initially, a physician stabilizes the patient's condition by treating infections, dehydration, and electrolyte imbalances. Then, a cautious feeding program is introduced, gradually increasing protein and calorie intake to allow for recovery and growth.

Can adults get protein-energy malnutrition?

Yes, adults can suffer from PEM, although it is more common in children. In adults, it is often linked to underlying diseases like cancer, HIV, chronic renal failure, or psychiatric conditions such as anorexia nervosa. The elderly are also a high-risk group.

What is the prognosis for someone with severe PEM?

The prognosis depends heavily on the severity and duration of the malnutrition, as well as the age of the patient and the presence of any complications. Early intervention offers the best chance of a full recovery, but long-term effects like stunted growth or cognitive impairment are possible, particularly in children.

What is refeeding syndrome?

Refeeding syndrome is a dangerous condition that can occur when severely malnourished individuals are fed too quickly. It involves a rapid shift in fluids and electrolytes that can lead to heart failure and other life-threatening complications. Treatment for severe PEM must always begin with caution to avoid this.