Marasmus (Severe Wasting Malnutrition)

What happens in marasmus

When intake of energy and protein is too low for a long time, the body adapts by breaking down fat stores and then muscle to fuel essential organs. Metabolism slows, body temperature and blood sugar regulation weaken, and the immune system becomes impaired. The gut lining thins, reducing absorption and causing diarrhea, which worsens malnutrition. In children, growth stops.

The word comes from the Greek marasmos, meaning "wasting away".

Causes

In children

• not enough food (food insecurity, poverty, famine, conflict)
• early stopping of breastfeeding without adequate replacement, or overly diluted formula
• repeated infections, especially diarrhea, measles, malaria, tuberculosis and HIV
• intestinal parasites
• feeding difficulties from cleft palate, cerebral palsy or other conditions
• neglect

In adults

• anorexia nervosa and other eating disorders
• advanced cancer, HIV, tuberculosis or other chronic illness
• severe depression, dementia or social isolation in older adults
• chronic alcohol use
• malabsorption from gut diseases

Symptoms and signs

• extreme thinness with visible ribs and bones
• severe muscle wasting, especially of the arms, thighs and buttocks ("baggy pants" appearance)
• loose, wrinkled, dry skin and an old-looking face
• thin, sparse, dry hair
• low energy, weakness, apathy or irritability
• poor growth: low weight and height for age (failure to thrive)
• chronic diarrhea and frequent infections
• low body temperature and slow heart rate
• hunger may be present early, though appetite often falls in complicated cases

Marasmus vs kwashiorkor

Some children have features of both, called marasmic kwashiorkor.

Diagnosis

In children, severe acute malnutrition is identified by:

• weight-for-height more than 3 standard deviations below the median, or
• mid-upper arm circumference (MUAC) below 115 mm (11.5 cm) in children aged 6 to 59 months, or
• swelling of both feet (indicating kwashiorkor)

Additional assessment includes appetite testing, signs of infection, dehydration, anemia and micronutrient deficiencies, and blood tests for blood sugar, electrolytes, HIV and other infections when available.

In adults, assessment uses body mass index, weight loss history, muscle mass and blood tests.

Treatment

Treatment follows a careful, staged approach, because rapid feeding can be fatal.

Stabilization (first days)

The WHO approach addresses immediate dangers:

1. Low blood sugar: give glucose or feeds immediately.
2. Low body temperature: keep warm with skin-to-skin contact and blankets.
3. Dehydration: cautious rehydration with a special low-sodium solution for malnourished children (ReSoMal), as standard fluids can cause heart failure.
4. Electrolytes: extra potassium and magnesium.
5. Infection: routine antibiotics, as infections are common and may cause few signs.
6. Micronutrients: vitamin A, zinc, folic acid and others; iron is delayed until the child is recovering.
7. Cautious feeding: small, frequent feeds of a starter therapeutic milk (F-75).

Rehabilitation

• Catch-up feeding with higher-energy therapeutic milk (F-100) or ready-to-use therapeutic food (RUTF), a peanut-based paste.
• Uncomplicated cases with good appetite can often be treated at home with RUTF in community programs.
• Emotional and physical stimulation and play support development.
• Follow-up to prevent relapse, including family nutrition education.

Refeeding syndrome

When feeding restarts after starvation, shifts in phosphate, potassium and magnesium can cause heart failure, breathing problems and death. Careful slow feeding and monitoring prevent refeeding syndrome.

Complications

• severe infections and sepsis
• low blood sugar and hypothermia
• heart failure
• vitamin deficiencies, including vitamin A deficiency causing blindness
• stunted growth and delayed development
• death, which is much more likely without proper treatment

Prevention

• Exclusive breastfeeding for the first 6 months, then nutritious complementary foods with continued breastfeeding
• Safe water, sanitation and handwashing to reduce diarrhea
• Vaccinations, especially measles
• Regular growth monitoring
• Food security programs and early identification of children at risk

Frequently asked questions

What is marasmus?

Marasmus is a severe form of malnutrition caused by a long-term lack of calories and protein. The body breaks down fat and muscle, leaving extreme thinness and weakness. It most often affects young children in areas of food shortage but can occur at any age.

What is the difference between marasmus and kwashiorkor?

Marasmus causes extreme wasting without swelling, from an overall lack of food. Kwashiorkor causes swelling of the feet, legs and face, skin and hair changes and an enlarged liver, and is linked to protein deficiency and infection. Some children have features of both.

Can marasmus be cured?

Yes. With proper treatment, including careful refeeding, therapeutic foods and treatment of infections, most children recover. Treatment must be gradual to avoid refeeding syndrome. Long-term growth and development may be affected if malnutrition was prolonged.

What are the signs of marasmus in a child?

Signs include very thin arms and legs, visible ribs, loose wrinkled skin, wasted buttocks, an old-looking face, low energy, irritability, poor growth and frequent infections. A very thin upper arm measured with a MUAC tape is a key screening sign.