Introduction

Marasmus is a serious form of malnutrition caused by a lack of calories and protein. This phenomenon is the result of poor food and nutrition over time, not a single event.

Signs of marasmus include tilted eyes, caved-in cheeks and sunken soft spots on the head (fontanelles).¹ 

This article provides a detailed insight into the complex association of marasmus with mental development and describes how malnutrition (severe) during critical phases in developmental growth can cause cognitive deficits that may impact neurological consequences later down the track.

Prevalence in developing countries

Although global malnutrition rates have decreased over time, they remain significant. The World Health Organization (WHO) estimated that 181.9 million children in developing countries were malnourished at the beginning of 2020. Tragically, five million children under the age of five die from malnutrition in these regions every year. Malnutrition in children causes serious health problems and creates a heavy economic burden. In the UK, for example, the public cost of malnutrition-related diseases was estimated at more than £13 billion a year in 2007.² In 2016, 0.5% of people in the United States had marasmus. It is more common in hospitalised children, especially those with chronic illnesses. However, the exact number of nonfatal cases isn't known because marasmus often isn't listed as a reason for hospital admission or discharge.³

Significant impact on children's health and development

Marasmus, a severe form of malnutrition, is primarily caused by inadequate food intake, infectious diseases, and low birth weight, particularly in cases of intrauterine growth restriction (IUGR). The root causes of malnutrition are varied, including poverty, poor sanitation, overcrowding, infections, maternal depression, and child neglect and abuse.²Children who don't get enough to eat or are born too small often struggle to gain weight and remain undernourished. Additionally, illnesses such as pneumonia, diarrhoea, measles, and tuberculosis can lead to marasmus, creating a vicious cycle where malnutrition makes children more vulnerable to infections, which in turn worsen their malnutrition.Preventing and treating malnutrition requires access to health services, a clean environment and safe water.⁴

Severe malnutrition causing marasmus can arise from not eating enough food, difficulties in absorbing nutrients, or poor utilisation of nutrients by the body.

Symptoms and diagnosis

Symptoms of marasmus

• Severe loss of fat and muscle tissue
• Noticeably prominent bones
• Head appears disproportionately large
• Aged and wrinkled facial appearance
• Dry, loose, and atrophic skin
• Brittle hair or significant hair loss
• Sunken soft spots on an infant’s head(fontanelles)
• Extreme lethargy, apathy, and weakness
• Weight loss exceeding 40% of normal weight
• Body Mass Index (BMI) lower than 16.¹

Diagnosing marasmus

Anthropometric measurements

Important measurements

• Height: precise to 0.5 cm
• Weight: precise to 100 g
• Mid upper arm circumference (MUAC): precise to 2 mm or less

Diagnosis criteria

• MUAC less than 115 mm
  • Weight-for-height Z score more than three standard deviations below average
• Check for Swelling: To rule out kwashiorkor

Lab tests

• WHO recommended tests:
  • Haemoglobin and blood smear
  • Blood sugar levels
  • Blood proteins (albumin) and electrolytes
  • Stool tests for parasites and bacteria
  • HIV testing
  • Urine tests for infections
• Other useful tests:
  • Complete blood count: checks haemoglobin and red blood cells
  • Blood smear: identifies anaemia and malaria
  • Iron levels, folic acid, and B12 levels

Nutritional status tests

• Key blood proteins:
  • Transferrin, albumin, and prealbumin
• Albumin:
  • Commonly used to check nutritional status
  • Not good for short-term changes due to long life span (19 days)
• Short-lived proteins:
  • Prealbumin (2 days) and retinol-binding protein (10 hours)
  • Better for monitoring quick changes in nutrition⁵

Impact on mental development

Recent studies have shown significant brain growth delays in children with severe protein-calorie malnutrition (PCM). This has been observed by measuring head circumference in living children and brain weight during autopsies. Head circumference is generally a good indicator of brain size, but this isn't always accurate. In severe PCM cases, changes in scalp and skull thickness can affect this measurement. Additionally, fluid buildup on the brain's surface or enlarged brain ventricles can further alter the head circumference-to-brain size ratio.⁶

The mental and psychomotor development of severely malnourished infants was studied during their nutritional and psychological treatment. The response to treatment varied significantly between younger and older infants. Older infants had severe delays in psychomotor development upon admission but showed significant improvement throughout the treatment. On the other hand, younger infants' conditions deteriorated during hospitalization. By the end of the treatment, most infants had recovered from their body weight deficits.⁷

Mechanisms affecting mental development

Infants with marasmus are better prepared to cope with severe malnutrition after birth because they experienced a poor nutritional environment in the womb, which affected their growth and made them expect a similar situation after birth. This fits with the idea that bodies can adapt in advance to expected conditions. A study found that these infants have more difficulties in brain responses, specifically in the N2 and P3 waves, which are linked to handling response conflicts and categorising stimuli. These issues were noticeable when they performed tasks that required distinguishing repetitive and new stimuli, such as in the Flanker and Oddball tests.⁸

Research on animals and children has shown that PEM harms the developing brain's biochemistry, leading to tissue damage, halted growth, and developmental issues. This includes problems with myelination (nerve fibre insulation), fewer neuron connections, and reduced overall brain activity. These effects have been observed in children through various methods, including clinical studies, brain size measurements, spinal cord analysis, nerve examinations, neuro-CT scans, MRIs, and changes in cerebellar cells.

The longer a child suffers from PEM, especially if they are younger and their mother is in poor health or has low literacy, the worse the effects on their nervous system. Just as nutrients are vital for brain development, a lack of environmental stimulation, emotional support, and affection also negatively impacts a child's growth. When both poor nutrition and lack of emotional support combine, the adverse effects are even more severe.⁹

Prevention and treatment

Resuscitation and stabilization

Main goals

• Rehydrate the child
• Prevent infections and sepsis
• Avoid complications like refeeding syndrome

Duration

• Approximately one week
• Critical phase as patients are highly susceptible

Dehydration treatment

• Use the intravenous isotonic solution
• In severe cases, use plasma or blood
• Keep the child in a warm room to prevent hypothermia

Infection management

• Children with marasmus may not show typical infection signs
• Administer antibiotics if sepsis is suspected, based on blood cultures
• Preventing refeeding ssyndromeIntroduce nutrition slowly
  • Maintain caloric intake between 60-80% of age requirement
  • Avoid hypoglycemia by feeding continuously at night or offering small nighttime meals
  • Provide vitamins like thiamine and oral phosphate to prevent hypophosphatemia

Monitoring for refeeding syndrome

• Watch for electrolyte imbalances to prevent arrhythmia, sudden death, weakness, muscle breakdown, confusion, and death
• Thiamine deficiency can cause brain issues or lactic acidosis
• Prevent fluid overload to avoid heart failure and swelling

Nutritional rehabilitation

1. Start phase:
   • Begin after treating acute complications
   • The child’s appetite returns, and electrolyte imbalances and infections are corrected
2. Nutritional intake:
   • Gradually increase caloric intake
   • Aim for 120-140% of the child's required calories to support growth
3. Additional measures:
   • Ensure vaccinations are up to date
   • Increase motor activity
   • Encourage mother-child interaction to support developmental recovery
4. Duration:
   • This phase can last from 2 to 6 weeks

Follow-up and prevention of recurrence

• Preventing Relapse:
  • Regular follow-up with patients
  • Educate mothers on breastfeeding and supplemental feeding

Reducing marasmus

• Ensure clean drinking water
• Provide adequate food supplies
• Control infectious diseases⁴

Summary

Marasmus is a severe form of malnutrition caused by prolonged inadequate intake of calories and protein, leading to extreme thinness, visible bones, weakness, and an aged appearance. It is common in developing countries and among children with chronic illnesses. The condition arises from insufficient food, nutrient absorption issues, or infections like pneumonia and diarrhoea, creating a cycle where malnutrition worsens susceptibility to infections. Symptoms include significant weight loss, loose skin, and sunken eyes.

Diagnosis involves measuring height, weight, and arm circumference, along with lab tests for  haemoglobin, blood glucose, and infections. Marasmus severely affects brain development and psychomotor skills.

Treatment begins with rehydration, infection prevention, and careful nutritional support to avoid refeeding syndrome, lasting about a week. Nutritional rehabilitation follows, gradually increasing calorie intake and encouraging mother-child interaction, lasting 2-6 weeks. Preventing relapse involves regular follow-ups, educating mothers on proper feeding, ensuring clean water, and controlling infectious diseases.

Malnutrition is most harmful early in life, so it’s crucial to focus on the nutritional needs of mothers and infants, especially during the first 1000 days from conception to age 2. Key actions include promoting exclusive breastfeeding for the first 6 months and continued breastfeeding until at least age 2.

Governments should educate people about healthy eating and implement social protection measures, like school feeding programs, to ensure vulnerable groups get nutritious diets. Efforts to combat obesity should include creating healthy environments that encourage physical activity from a young age.

Today, we better understand the complexity of malnutrition and know the strategies needed to tackle its many challenges. Solving the global food crisis requires a global solution, and the international development process needs to pay more attention to the food crisis.¹⁰