[Results of the sweat test, carried out by 2 methods, for the diagnosis of cystic fibrosis].

Un review the results of the sweat test for the diagnosis of cystic fibrosis performed by 2 methods: Electric conductivity of the sweat (2,517 test in non-cystic fibrosis and 114 in 37 cystic fibrosis children) and skin chloride electrode (121 test in non-cystic fibrosis and 20 in cystic fibrosis children). A 1% rate of false positive results was obtained with the former along with 6,1% falsely negative results in cystic fibrosis patients. The skin chloride electrode method was much less specific and sensitive. The diagnosis of cystic fibrosis should only be made once repeatedly altered sweat chloride concentrations are obtained together with careful correlation with the clinical findings. We think that both the implications of the diagnosis and the thoroughness needed in the proper performance of the sweat test warrant that the diagnosis should always be confirmed in a centre with experience in the disease.