PlumpyNut was not developed for children suffering from kwash, but as it turns out, PlumpyNut works pretty well for these kids.
The composition of PlumpyNut is 30% milk powder, 28% sugar, 25% peanut paste, 15% oil (usually soy bean oil - this has the most advantageous omega 6: omega 3 ratio) and combined mineral+vitamin mix. The product specifications require that the total sodium content of Plumpy be less than 290 mg per 100 grams of product, compared to 1100-1400 mg potassium per 100 gr product, so the comparative load of sodium is quite low. You can conceptualize PlumpyNut as F100 therapeutic milk + iron - mixed into a lipid based food matrix so that the consistency is soft and the micronutrients are protected from oxidation by virtue of the barrier created by the lipids. So in as much as the basis of treatment for kwash is milk, then PlumpyNut makes sense - as long as the sodium content is minimized. On page 6 of the UN Joint Statement on Community Management of Acute Malnutrition, you have the specifications for RUTF (which are actually those for F 100).
In MSF programs, we usually handle kwash in the following way: 1+ edema with satisfactory appetite and no medical complications: home-based therapy with PlumpyNut >1+ edema, hospitalization for F75 until edema mobilizes then moving to F100 or PlumpyNut. Discharge when weight for height is >-2Z WHO. Of course, any child with anorexia or any medical complication such as respiratory infection, skin infection is hospitalized for appropriate treatment (ng feeds, parenteral antibiotics) .
But if the child has appetite and the edema is minimal, home based care for kwash is quite alright.
100+ years after its initial descriptions, we still really have no idea what causes kwash.
As relates to PlumpyNut and PlumpyDoz: the food (lipid) matrix is identical for each of these foods (milk+sugar+peanut+oil), but the micronutrient concentration in PlumpyDoz is slightly higher so that daily consumption of a smaller amount (45 g) delivers a full daily RNI of micronutrients to the child. PlumpyNut is tailored to be consumed at at least 184 grams per day, so the micronutrients are less concentrated except for potassium - which is always very depleted in SAM.
Susan Shepherd, MD
Coordinator - Nutrition Working Group
Medecins sans Frontieres
mailto:Susan.Shepherd@newyork.msf.org