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Sweat test

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

What is a sweat test?

Your doctor has asked us to give your child a sweat test. In this test, we collect a small amount of sweat from the skin and test it to see if your child has a condition called cystic fibrosis. Cystic fibrosis is a genetic disease that affects the lungs and digestive system.

How is it done?

The sweat is collected by applying a very small electrical current to your child's skin along with a chemical called pilocarpine. Pilocarpine helps to cause sweating. The test is usually done on your child's arm or leg. The sweat collected is tested for salt content. In most cases a high salt content indicates cystic fibrosis.

How long does it take?

The sweat test usually takes about a half to one hour.

Does it hurt? Is it safe?

Sweat testing is a very safe procedure and thousands of children have the test without any problem. It usually causes only minor discomfort. Because the child's skin heats up over a small area during the test, there is a very slight risk of causing a minor skin inflammation. Young babies less than six weeks old are most affected. In extremely rare circumstances, the heating of the skin has been known to cause a very small superficial burn.

On rare occasions, we cannot collect enough sweat for the test, for instance, in very small babies. If this happens, we will have to repeat the test some weeks later.

• Sweat testing is a safe procedure.
• The test may have to be repeated if not enough sweat is collected.
• Should only be performed at a recognised centre for sweat testing.

The Children's Hospital at Westmead Tel: (02) 9845 3585 Fax: (02) 9845 3562 www.chw.edu.au	Sydney Children's Hospital, Randwick Tel: (02) 9382 1688 Fax: (02) 9382 1451 www.sch.edu.au	Kaleidoscope, Hunter Children's Health Network Tel: (02) 4921 3670 Fax: (02) 4921 3599 www.kaleidoscope.org.au