What is the method used for sweat chloride testing?

• A. Gibson and Cooke Pilocarpine Iontophoresis Method
• B. Wickham method
• C. Taylor sweat test
• D. Silverman method

Answer: (A)

Sweat chloride testing relies on provoking sweat in a controlled way so the sample is reliable. The method that has become the standard is pilocarpine iontophoresis, described by Gibson and Cooke. In this approach, a small current drives pilocarpine into the skin to stimulate the eccrine sweat glands, producing enough sweat to collect. The sweat is gathered on a collection device and then the chloride concentration is measured. This setup—stimulation by pilocarpine via a controlled electrical method and standardized collection—provides consistent, interpretable results for diagnosing conditions like cystic fibrosis. The other methods are older or less commonly used variants and don’t define the current standard approach for obtaining sweat samples in routine testing.