Nutritional Deficiencies
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Direct answer
Marasmus and kwashiorkor are the two poles of protein-energy malnutrition in MBBS Pathology: marasmus is deficiency of total calories in infancy, giving weight below 60 per cent of expected, gross wasting of muscle and fat, an alert hungry child and no oedema, while kwashiorkor is predominant protein deficiency after weaning, giving oedema, apathy, flaky-paint dermatosis, a fatty enlarged liver and the flag sign in the hair. Each vitamin deficiency leaves a reproducible tissue signature — squamous metaplasia in vitamin A deficiency, failed collagen cross-linking in vitamin C deficiency, unmineralised osteoid in vitamin D deficiency and megaloblastic marrow in vitamin B12 and folate deficiency. Examiners test the lesion and the programme point, not the diet chart.
What you must remember
- Marasmus: weight below 60 per cent of expected, first year of life, muscle and subcutaneous fat visibly wasted, child alert and hungry, no oedema; head looks large for the shrunken body.
- Kwashiorkor: weight 60–80 per cent of expected plus oedema, hypoalbuminaemia, apathy, anorexia, flaky-paint dermatosis, hepatomegaly from fatty change, depigmented easily plucked hair (flag sign); mortality higher than marasmus.
- Vitamin A: keratinising squamous metaplasia of conjunctival glands — night blindness, Bitot spots, corneal ulceration, keratomalacia; leading cause of preventable childhood blindness; India gives prophylactic megadose vitamin A from nine months of age.
- Vitamin D: osteoid laid down but not mineralised — rickets in children (rachitic rosary, Harrison sulcus, bowed legs, widened wrists) and osteomalacia in adults (Looser zones).
- Vitamin C: proline and lysine cannot be hydroxylated, so collagen is unstable — bleeding gums, perifollicular haemorrhages, painful tender legs, poor wound healing.
- B-complex: thiamine — wet and dry beri beri and Wernicke encephalopathy; niacin — pellagra of dermatitis, diarrhoea and dementia; B12 and folate — megaloblastic anaemia, with B12 adding subacute combined degeneration of the cord.
- Vitamin K: factors II, VII, IX and X fall — haemorrhagic disease of the newborn, prevented by the intramuscular vitamin K dose given at birth.
- Iodine and zinc: iodine deficiency gives colloid goitre and cretinism, countered by iodised salt under the National Iodine Deficiency Disorders Control Programme; zinc deficiency mimics acrodermatitis enteropathica with periorificial rash and diarrhoea.
Two children, one comparison
Picture two one-year-olds on the same paediatric ward. The first is a marasmic infant: skin and bones, ribs clearly visible, alert eyes following the doctor, desperately hungry, and oedema absent. The body has adapted to starvation by switching off growth and insulin-mediated storage — metabolism is switched down, albumin is preserved. The second has kwashiorkor after a recent weaning onto a starch-heavy diet: pitting pedal oedema, a moon-like apathetic face, cracked flaky skin over the buttocks and thighs, an enlarged smooth liver and pale sparse hair that comes away in clumps between thumb and finger. Here the adaptation has failed: acute protein deficit drops albumin, the oedema is oncotic, and the liver fills with fat because apolipoprotein synthesis has stalled while carbohydrate keeps arriving.
Management order matters more than the diet sheet: treat hypoglycaemia, hypothermia and infection first, then graded feeding — the WHO sequence of stabilisation with F-75 followed by F-100 or ready-to-use therapeutic food, the same protocol used in India's facility-based severe acute malnutrition care under the national nutrition mission, POSHAN Abhiyaan. This comparison, written with the flag sign and the two weights as anchors, is what a viva examiner wants.
Where the exam separates candidates
The classic slip is calling every malnourished child with swelling kwashiorkor — nephrotic syndrome and kwashiorkor both give pitting oedema with hypoalbuminaemia, and in Indian admissions they coexist; urine protein separates them. The second trap is mixing up the two rosaries. The rachitic rosary of vitamin D deficiency is a knobby, firm, painless beading of the costochondral junctions from cartilage overgrowth; the scorbutic rosary of vitamin C deficiency is tender, and the costochondral junctions appear angular and depressed. Finally, the flag sign does not mean a single pale streak — it describes alternating bands of darker and lighter hair that record intermittent periods of protein adequacy, which is why it is asked by name in vivas.
Frequently asked questions
Which single clinical feature separates kwashiorkor from marasmus?
Oedema. Kwashiorkor has pitting oedema on a background of hypoalbuminaemia; marasmus has identical calorie-driven wasting without oedema.
What is the flag sign in protein-energy malnutrition?
Alternating bands of normally pigmented and depigmented hair reflecting fluctuating protein intake; the hair is also soft, sparse and easily plucked in kwashiorkor.
Which deficiency produces Bitot spots?
Vitamin A deficiency; Bitot spots are foamy grey conjunctival plaques of keratinised metaplastic glands, progressing to corneal ulceration and keratomalacia if untreated.
Why does vitamin C deficiency cause bleeding?
Ascorbic acid is a cofactor for prolyl and lysyl hydroxylase; without hydroxylation, collagen triple helices are unstable and vessel wall connective tissue fails, so gums bleed and perifollicular haemorrhages appear.
What is F-75 in malnutrition management?
The low-protein, low-sodium, high-energy starter milk used in the stabilisation phase of severe acute malnutrition before transition to F-100 or ready-to-use therapeutic food.