II. Indication
- Cystic Fibrosis testing
III. Method
- Quantitative Pilocarpine Iontophoresis
- Stimulates local sweat production (parasympathetic)
- Collect sweat on gauze pads
- Analyze Sodium and chloride content
- Minimum sweat amount required: 50 mg (200 mg better)
IV. Normal
- Sweat contains <60 meq/Liter Chloride and Sodium
V. Abnormal Results
VI. Indications to repeat the test for confirmation
- Positive Test
- Suspected False Negative
VII. False Positive Tests
- Glucose 6 Phosphate Dehydrogenase deficiency (G6PD)
- Hypothyroidism
- Glycogen Storage Disease
- Untreated Adrenal Insufficiency
- Malnutrition
VIII. Reference
- Bakerman (1984) ABC's of Lab Data, ILD, Greenville, NC