The source of Na+ and Cl- activities on the skin surface. Experiences with electrode measurements in children.

We have used ion-specific electrodes in an attempt to map the sodium 
and chloride activities on the skin under differing surface conditions. The 
range of values and the standard deviations are so wide that 
a baseline for the untreated dry skin is precluded. In patients 
with cystic fibrosis, a wide range of values is also found. 
For this group, measurements on dry skin taken immediately after washing 
were in the same low range as for healthy subjects. The 
range of measurements on the dry skin of newborn infants was 
similar for full-term infants with reactive sweat glands and for premature 
infants who failed to show sweating responsiveness to natural reflex stimulation 
as well as local glandular stimulation with sudorific drugs. For only 
two conditions have measurements of sodium and chloride activities on the 
surface of the skin been of value: (1) on the sweat-covered 
skin for the detection of the high values encountered in cystic 
fibrosis, and (2) on the dry skin surface, deprived of autonomic 
innervation (spinal paraplegia), extremely low sodium and chloride activities reflect absent 
gland activity. 