Letter: Skin wrinkling in cystic fibrosis.

Professor Elliott and Dr Norman and his colleagues suggested that excessive wrinkling 
of the skin after soaking in tap water might provide an 
easy, cheap, and probably reliable screening test for cystic fibrosis. Our 
results show that this not true. Marked wrinkling after immersion of 
the fingers in warm tap water for 5 minutes was observed 
in randomly selected children with a wide variety of conditions, including 
not only cystic fibrosis but also malnutrition and renal, heart, endocrine, 
collagen, and other diseases. It was elicited even in apparently healthy 
individuals, both young and adult. 