Abnormally high sweat osmolality in children with Down's syndrome.

There are few data on sweat analysis in Down's syndrome. We studied 25 children with Down's syndrome and obtained sweat samples by pilocarpine iontophoresis. Sweat osmolality was elevated in Down's syndrome compared to normal. The results of sweat testing must be regarded with caution when cystic fibrosis is suspected in children with Down's syndrome.