There are other forms that pit. The nutrition specific sign is bilateral pitting oedema. Many other causes of pitting oedema (e.g. DVT, lymphatic filariasis) are likely to present unilaterally. Those that do present bilaterally (e.g. due to venous stasis in the bed-bound, varicose veins, heart failure, liver failure) will be very rare in children. So ... we treat bilateral pitting oedema as the principal sign for Kwashiorkor. If you suspect a non-nutritional cause for bilateral pitting oedema then you refer to clinical services.

Just to back up Mark's point with an obvious but sometimes forgotten lesson taught in medical schools: "Common things are common.." Hence, in a kwash prevalent setting, if oedema is bilateral and especially if child is otherwise stable/"uncomplicated".. .then it's likely kwash and there's rarely a rush to do anything else. There maybe other signs of kwash (e.g sparse hair, flaky paint dermatosis, large liver) that help point towards the diagnosis, but these are NOT essential to define a case and are often not present in early kwash as picked up by proactive CMAM programmes. Main thing is not to start off doing lots of other tests/investigations/referrals and looking for other causes routinely. That'll waste time and resources. The main differentials rarely need urgent treatment. (DVT does - but that's unlateral oedema) Most children will get better with standard nutrition treatment. Response to treatment itself is helpful confirming the diagnosis of kwash. HOWEVER..if the oedema has not settled (or if is not at least improving...) after a week or so, THEN is the time to start thinking more widely. There'll be variations in different settings, but a reasonable follow-on plan where oedema is not getting better is: 1) Urine dipstick to exclude kidney problems (nephrotic syndrome being the main differential diagnosis. Not common, but equally not rare, so you will see cases. Relatively simple to diagnose with urine dipstick - you'll see heavy +++ proteins in the urine) 2) Clinical exam of heart (+chest x-ray where available) to exclude heart failure 3) Clinical exam of abdomen - to exclude any masses (e.g cancer / abdominal TB) which may be obstructing the lymphatic drainage from the legs (though these are more likely to cause unilateral oedema) But indeed..refer in for clinical opinion if the oedema is not settling. Close links with clinical colleagues are important in that hopefully they'll also refer the other way - their patients who are eligible for nutritional support but who for whatever reason have gone straight to hospital/clinic and missed out on nutrition assessment. Best wishes, Marko