in the extreme changes in elastin caused by a decrease in moisture. Impaired elasticity (which may result from loss of as little as 3.4% in wet weight) prolongs the cutaneous recoil time by 40 times, delaying the skin’s ability to spring back into place, and thus resulting in “tenting”—the lingering of the skin as a crease above the abdominal plane.
Since older patients have less elasticity, this test has no real diagnostic value in adults. In children, instead, it is useful. Yet, since skin turgor may reflect not only the level of hydration
(including electrolyte status) but also the level of nutrition (i.e., the amount of subcutaneous fat), “tenting” can be absent in cases of obesity or hypernatremic dehydration. Hence, the standard assessment of hypovolemia in all patients remains a set of basic laboratory tests: serum electrolytes, urea nitrogen, and creatinine.