Explained: Kwashiorkor, malnutrition's biggest unknown
Forty-three million children suffer from acute malnutrition globally. Nearly a third have severe acute malnutrition (SAM), which is life-threatening. But these numbers don’t measure kwashiorkor, an undercounted form of SAM where the body looks swollen.
It’s still unclear what causes kwashiorkor, even though children are much more at risk of death from it. These malnutrition figures come from national surveys which mostly identify children with marasmus, the more well-known form of malnutrition where children lose their fat and muscles and look very thin.
The reason kwashiorkor is undercounted is because these surveys don’t measure ‘nutritional oedema’ – this is where parts of the body, or even the whole body looks swollen due to the build-up of fluid in the body's tissues.
What does kwashiorkor look like?
In children with kwashiorkor, the oedema develops in their lower limbs and can spread to other parts of the body including the face. The more widespread the oedema, the more severe the condition, and the more at risk of death the child is.
Its impact is so severe it can leave patients with serious disabilities, both cognitively and physically, into adulthood.
Children with kwashiorkor can have white hair, enlarged livers and skin lesions which look like burns. They often can’t control their own temperature and sugar levels, which leads to many complications.
There are no specific tools or laboratory tests to diagnose kwashiorkor, meaning that medical staff rely solely on a physical examination.
One of the main indicators of oedema is when a small ‘pit’ on the skin remains on both feet, legs etc, after a health worker has pressed their thumbs for a few seconds on their skin.
“In MSF’s Katsina project in Nigeria, 45 percent of children with kwashiorkor needed hospital care, compared to only 12 percent of those with marasmus.”
Why is it important to understand kwashiorkor?
We still don’t know exactly why some children develop kwashiorkor while others develop marasmus. Without understanding the disease and what causes it, it’s difficult to know how to better prevent, detect and treat it.
“I didn’t think it was malnutrition. I thought it was just a fever, because these kinds of things are difficult to identify,” said Badiyya Shafi’u, whose child was treated by Médecins Sans Frontières / Doctors Without Borders (MSF) for kwashiorkor in the city of Katsina, northwest of Nigeria.
The impact of kwashiorkor is clear. Evidence from many studies (such as these ones from 2019 and 2025) has shown a higher mortality rate amongst children with kwashiorkor compared to those with marasmus. Many clinicians who care for children with kwashiorkor, especially those in hospital, report that they deteriorate quickly, with no warning and often with severe consequences.
While working in Katsina state, our teams found that only around 9 percent (15,132) of the 172,303 malnourished children that were admitted to nutrition centres had kwashiorkor.
However, 45 percent of these children with kwashiorkor needed admission to hospital, compared to 12 percent of those with marasmus.
This shows that although marasmus is more common, kwashiorkor is often more serious.
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Why do we know so little about kwashiorkor?
A lack of resources and focus on kwashiorkor means there are large gaps in knowledge, especially its causes, epidemiology, and geographical distribution.
Research is often not practical. Studies need large numbers of blood, skin, urine and faeces samples from children, and keeping these samples stable while transporting them over long distances for analysis is a challenge.
MSF is one of the few organisations that researches the cause of kwashiorkor as well as providing care for children affected.
A recent study at an MSF project in Niger showed that kwashiorkor children have some specific protein and fat molecules in their blood which leads to the oedema. Although this study could only use a small sample, it is a promising development in understanding the condition.
How do we treat kwashiorkor?
Treatment for kwashiorkor is the same as for children with marasmus, and has three main areas:
1. Medical care – the child is assessed and their medical history considered. They are screened for HIV and tuberculosis (TB), as these can often cause malnutrition. If a child has severe medical problems, they will be transferred to a hospital.
2. Nutritional care – in hospital children are started on therapeutic milk F-75. This is designed to stabilise the child’s metabolism in a controlled way. When the oedema has reduced, they are either given a different type of therapeutic milk or a ready-to-use therapeutic food (RUTF). RUTF is nutrient- dense and helps them gain weight and recover enough for them to leave hospital and have weekly follow ups at a clinic
3. Psychosocial care – malnutrition can lead to physical and cognitive delay, or even regression. Physiotherapy, play therapy and other interactive activities help. Both children and their caregivers often need mental health support due to the stresses that malnutrition puts on a family.
For children with kwashiorkor, closer attention must always be paid to how their condition evolves, looking out for any signs of deterioration.
They often need specialised skin care. MSF has developed evidence-based protocols to manage kwashiorkor skin lesions.
"There are large gaps in kwashiorkor knowledge, especially in terms of causes, epidemiology, and geographical distribution."
How can kwashiorkor be prevented?
It’s important to note that malnutrition cases like kwashiorkor are not always simply caused by hunger. Even where food is available, it can be caused by repeated bouts of diarrhoea or undiagnosed illnesses such as TB, coupled with unavailable healthcare.
Prevention of kwashiorkor is the same for all acute malnutrition. The following activities help:
- Providing quality care during and after pregnancy, which reduces the risk of low birth weight and malnourishment. Breastfeeding support is crucial here.
- Providing children with vaccination, growth monitoring, and screening and treating for HIV and TB.
- Children accessing a nutritious diet which meets all their needs for growth and development in a family environment which is hygienic and safe.
MSF draws on its operational experience, research and medical expertise to provide care that addresses the needs of the whole child.
Pyschosocial care is essential for both prevention and treatment. In Katsina state, we organise educational sessions for caretakers to help identify kwashiorkor in the community as well as discussing their general needs and ideas related to health and nutrition.
MSF and malnutrition
Malnutrition is a devastating global healthcare crisis.
Around the world, 43 million children suffer from acute malnutrition with 12.2 million of those with the most severe form – which is a life threatening condition.
Nearly half of all deaths in children under 5 years is associated with undernutrition.
Greater resources for research, prevention and care for malnutrition are needed to help save the lives of thousands of children.