A Simple method for Collection and Analysis of Sweat for Chloride

Abnormally high concentrations of sodium and chloride in the sweat of patients with fibrocystic disease of the pancreas were first noted by Darling, di Sant'Agnese, Perera, and Andersen, in 1953.¹ Papers supporting and extending this observation * appearing since that time would indicate that a high chloride concentration in the sweat is the most constant of the numerous manifestations of cystic fibrosis of the pancreas. Because of the diagnostic importance of the determination of sweat chloride, an effort has been made to devise a simpler procedure for the collection of sweat than that commonly used. In the studies mentioned above, sweat for analysis was produced by thermal stress, either by placing the subject in a room at 90 F for one to two hours † or by encasing the trunk and extremities in a plastic bag.⁵ The present communication describes a method for local production of sweat by intradermal