This is the commonest form of severe malnutrition. The child’s weight is far below the 3rd centile and lies below 60% of the 50th centile (the ‘marasmus line’). These children usually appear very thin (severely wasted) and are often ill. They do not have oedema. Marasmus is usually due to starvation or severe illness such as malabsorption or AIDS.
Children with marasmus are severely underweight for their age.
Children with marasmus have a weight-for-height less than 60% of expected (under 3 SD below the mean). Some serious medical conditions (e.g. malabsorption) can also result in marasmus.
The severe wasting is best seen on the buttocks, thighs and upper arms where the skin hangs in folds. The ribs and shoulder blades stick out and the abdomen is usually distended due to decreased muscle tone. They are anxious, irritable, cry easily and look like an old person.
Anorexia nervosa causes marasmus in older children and adolescents.