Dear Anonymous,
Malnutrition causes pathophysiological changes that affect every organ and system in the body including skin. Children that have been identified with Severe Acute Malnutrition for example will undergo a general medical examination (for example using the IMCI framework). Typically the examination will identify illnesses that may have contributed to or may be a consequence of malnutrition. The assessment record (OTP card) that is/was used by NGO's would typically identify specific features such as 'scabies' or 'lymph nodes' depending on context.
Scabies is context specific, meaning that in some contexts many children with SAM coincidentally have scabies. Scabies is identified and treated as a public health intervention rather than being specific to SAM.
Ulceration of the skin may occur in SAM resulting in open wounds of the limbs, particularly in cases of severe oedema. In some contexts there may be a high prevalence of bacterial skin infections that will need attention in addition to the other treatment protocols.
Lymph node checks are a normal part of a medical examination. Swollen lymph nodes in isolation may be due to a local infection in one or more limbs. Generalised swelling of lymph nodes may be indicative of generalised infection (e.g. Influenza) but may also sometimes be related to illnesses such as TB, HIV or malignant disease. While checking lymph nodes is a normal part of any examination it may be that in some contexts the check (on OTP cards) may be emphasised due to a high prevalence of HIV/TB, for example.
Candida may be the result of immunosuppression (which may be a direct consequence of SAM) or may be indicative of generalised illness such as TB / HIV. Checking the mouth should be a standard part of any medical examination since the clinician may also detect problems (e.g. cleft palate or dysphagia) that may be a barrier to eating RUTF for example for children with SAM.
A quick internet search came up with this briefing by Save the Children that gives a brief overview of some of the physiological consequences of malnutrition.
http://www.knowledgemeridian.com/wwv/MalnutritionBriefingForDoctorsAndNurses.pdf
If you would like to investigate the pathophysiology further I would recommend researching the work of Professor Michael Golden.
I hope this helps
Paul