Pathology Cheat Sheet
Deficit and Excess in Tissue
Malnutrition and obesity for NEET-PG: marasmus vs kwashiorkor, vitamin A, D and C deficiency, pellagra, beriberi, and the obesity metabolic syndrome here.
MedNext Academy | 3 min read
Deficit and Excess in Tissue
Malnutrition and obesity for NEET-PG: marasmus vs kwashiorkor, vitamin A, D and C deficiency, pellagra, beriberi, and the obesity metabolic syndrome here.
The pathogenesis of protein-energy malnutrition, key vitamin deficiencies, and the metabolic consequences of obesity.
High-yield lines
- Protein-energy malnutrition ranges from total caloric lack in marasmus to selective protein deficiency in kwashiorkor.
- Marasmus depletes both fat and muscle, causing severe wasting with preserved albumin and no oedema.
- Kwashiorkor features hypoalbuminaemia, oedema, fatty liver, and skin and hair changes despite relatively preserved subcutaneous fat.
- Vitamin A deficiency causes night blindness, xerophthalmia, Bitot spots, and keratomalacia.
- Vitamin D deficiency causes rickets in children and osteomalacia in adults.
- Vitamin C deficiency causes scurvy with defective collagen, bleeding gums, and poor wound healing.
- Thiamine deficiency causes beriberi and Wernicke-Korsakoff syndrome.
- Niacin deficiency causes pellagra with dermatitis, diarrhoea, and dementia.
- Obesity is defined by a body mass index of 30 or more and reflects visceral adiposity with chronic low-grade inflammation.
- Visceral adipose tissue secretes adipokines and free fatty acids that drive insulin resistance.
- Obesity is central to the metabolic syndrome and causes type 2 diabetes, dyslipidaemia, hypertension, and non-alcoholic fatty liver disease.
- Obesity increases the risk of several cancers, obstructive sleep apnoea, and atherosclerotic cardiovascular disease.
Mapped competency codes
- PA12.2
- PA12.3
Continue into the full chapter
This summary maps to PA12-environmental-and-nutritional-diseases.
Frequently Asked Questions
How do marasmus and kwashiorkor differ?
Marasmus is total calorie deficiency causing severe wasting of fat and muscle without oedema, while kwashiorkor is protein deficiency with hypoalbuminaemia, oedema, and fatty liver.
What are the features of vitamin A deficiency?
Night blindness, conjunctival xerosis with Bitot spots, xerophthalmia, and in severe cases keratomalacia and blindness.
How does visceral obesity cause metabolic disease?
Visceral fat secretes adipokines and free fatty acids and generates chronic inflammation that produces insulin resistance and the metabolic syndrome.
What deficiency causes the three Ds of pellagra?
Niacin deficiency, which produces dermatitis, diarrhoea, and dementia.
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