Final answer:
The 'skin and bones' appearance in severe protein-calorie malnutrition is associated with marasmus, a condition caused by extremely low intake of both protein and calories, leading to the wasting of muscle and subcutaneous fat.
Step-by-step explanation:
The type of protein-calorie malnutrition that leads to severe muscle wasting and a "skin and bones" appearance is marasmus. Marasmus is a form of severe undernutrition caused by a significant deficiency in both protein and calorie intake. Unlike kwashiorkor, which is characterized by adequate energy intake but low protein consumption leading to a swollen abdomen and edema, marasmus results in extreme wasting of subcutaneous fat and muscle mass without edema, a condition also known as calorie malnutrition.
Marasmus is more likely to occur in situations of famine, in children of poor families, or when a child has been fed only on mother's milk for an extended period without additional dietary sources of nutrition. The marasmic condition comes from a Greek word meaning "wasting away," and it presents with symptoms such as low body temperature, anemia, dehydration, and extremely thin limbs, giving the affected individual a "skin and bones" appearance. Protein-calorie malnutrition like marasmus demands immediate intervention to provide adequate nutrition to reverse the wasting process and prevent potentially fatal outcomes.