General pathology · Nutritional pathology
Severe acute malnutrition: marasmus and kwashiorkor !
- Topic
Children who lack enough food waste away (marasmus) or swell with oedema (kwashiorkor); both weaken immunity and can be fatal.
Updated 2026-11-01
What it is
Severe acute malnutrition remains a major cause of child death in low-income settings, and in Colombia it still affects children in areas such as La Guajira. Marasmus is a lack of total energy with severe wasting; kwashiorkor shows oedema, fatty liver and skin changes, classically when protein is especially lacking, often triggered by infection. Both cause atrophy of many organs and a secondary immunodeficiency.
Key facts
- Marasmus: loss of muscle and subcutaneous fat, «skin and bones», old-looking face; serum albumin near normal; no oedema.
- Kwashiorkor: pitting oedema, low albumin, large fatty liver, flaky-paint skin, sparse light-coloured hair with bands of colour.
- Both: small intestine villous atrophy (diarrhoea), thymic atrophy with low T-cell immunity, anaemia and micronutrient deficiencies.
- Brain growth may be impaired when malnutrition occurs in the first years of life.
Step by step
- Intake falls short of needs; glycogen is used in hours, then fat, then muscle protein.
- Insulin falls and cortisol rises: muscle is broken down to feed the liver.
- In kwashiorkor the liver makes too little albumin and apolipoproteins: oedema and fatty liver.
- Mucosal and thymic atrophy cripple barriers and T cells: diarrhoea, pneumonia and measles become deadly.
- Fast refeeding shifts phosphate, potassium and magnesium into cells: refeeding syndrome.
Marasmus and kwashiorkor compared
| Form | Main deficit | Oedema and albumin | Liver | Skin and hair |
|---|---|---|---|---|
| Marasmus | Total energy | No oedema; albumin near normal | Normal size | Thin, loose skin; muscle and fat wasted |
| Kwashiorkor | Relatively more protein, often with infection | Pitting oedema; low albumin | Enlarged, fatty | Flaky-paint dermatosis; sparse, pale hair with colour bands |
Test yourself
Think of the answer, then tap the question to see it.
Why does a child with kwashiorkor have a fatty liver?
Without enough protein the liver cannot make the apolipoproteins needed to export triglycerides as VLDL.
Which feature best separates kwashiorkor from marasmus?
Oedema with low albumin; the marasmic child is wasted but has no oedema.
Which electrolyte typically falls dangerously during refeeding of a malnourished patient?
Phosphate, which moves into cells when insulin rises; potassium and magnesium also fall.
Why do malnourished children die of common infections?
Thymic and mucosal atrophy weaken T-cell immunity and barriers, and micronutrient deficiencies add to the problem.
Related
- Atrophy
- Fatty change (steatosis)
- Cachexia, anorexia nervosa and bulimia
- Vitamin deficiencies: what each one does to tissue
- Edema and effusions: the four mechanisms
Related conditions
- Marasmus
- Kwashiorkor
- Refeeding syndrome
- Failure to thrive (faltering growth)
- Malnutrition and unintentional weight loss in older adults
- Vitamin A deficiency (night blindness and xerophthalmia)
- Zinc deficiency (acrodermatitis enteropathica)
- Iron deficiency anaemia
- Acute (viral) gastroenteritis
- Dehydration in children (acute diarrhoeal disease)
- Measles
Elsewhere in DurgiPedia
- Fed, fasting and starvation states
- Prolonged fasting and starvation
- Protein quality and essential amino acids
- Nitrogen balance and body protein
- Albumin
- Secondary immunodeficiency: HIV, malnutrition, drugs, asplenia
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Fact sheets - Malnutrition (World Health Organization, 2026); Kwashiorkor: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Malnutrition: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.