Which condition's diagnosis relies on a positive sweat chloride test?

A positive sweat chloride test is a cornerstone in the diagnosis of cystic fibrosis. This genetic disorder affects the transport of chloride and sodium ions across epithelial tissues, leading to the production of thick, sticky mucus in various organs, particularly the lungs and pancreas. The sweat chloride test measures the level of chloride in sweat; individuals with cystic fibrosis typically have elevated chloride levels. This is due to a mutation in the CFTR gene, which is responsible for sodium and chloride transport.

In contrast, while exocrine deficiencies, chronic pancreatitis, and atrial septal defects can be associated with various symptoms and complications, they do not utilize the sweat chloride test as a diagnostic criterion. Therefore, the reliance on the sweat chloride test specifically points to cystic fibrosis as the correct condition.