What is Cystic Fibrosis?

Cystic Fibrosis (CF) is a genetic disorder (passed from parents to child) that results in a defective protein affecting many functions of the body including digestion, breathing and reproduction. It can affect both males and females, and it can become worse with age.

The symptoms and severity of CF are different for each person. In some people only the lungs are affected while others have both lung and digestive problems. The common symptoms of CF include:

• excessive mucus production,
• a cough that doesn’t go away,
• pneumonia that keeps coming back, wheezing, sinus infections,
• nasal polyps (bumps inside the nose),
• poor growth,
• frequent foul-smelling stools,
• enlarged fingertips and
• salty tasting skin.

CF does not affect intelligence.

In CF the glands that produce mucus, saliva and intestinal fluids do not work properly. These glands produce secretions that are thick and sticky rather than thin and watery. Thick mucus in the lungs interferes with the removal of dust and germs and can cause breathing problems, infections, and lung damage. In the stomach, this thick mucus stops food being digested properly which slows growth and development.

The sooner CF is diagnosed the sooner treatment can begin. Treatment improves the length and quality of life of people with CF. Antibiotics and physiotherapy can reduce the effects of thick mucus in the lungs. Enzymes and special diets can improve nutrition. In some cases, newer medications that correct the protein causing the problems can improve the body’s functioning.

Please see your doctor for more information or further explanation about this condition.

What is a sweat test and how is it done?

People with Cystic Fibrosis produce higher amounts of salt in their sweat. Based on this observation, the sweat test was developed in the 1950s to diagnose CF. This test is still the standard test used to diagnose CF. It is also now used for monitoring patients receiving the newer treatment.

Note: it is very important that you have plenty to drink during the day of the test as this will help you to produce sweat.

The sweat test has three parts:

Pilocarpine iontophoresis:

A sweat-inducing drug called pilocarpine, is delivered from the surface of the skin into the sweat glands by a small electric current. The electric current is supplied by a battery-powered device through a pair of electrodes. These electrodes are covered with pilocarpine gel and strapped to your forearm. The electrical current is passed through the electrodes for 5 minutes. This can produce a mild tingle but no pain. This procedure, known as pilocarpine iontophoresis, a safe and effective method of stimulating sweat glands.

Sweat collection

• The electrodes are then removed, and a sweat collector (about the size and shape of a wristwatch) is strapped to the same spot. The sweat collector must stay on for 20-30 minutes to collect enough sweat. During this time, you can move around freely.
• If you would like to watch a video of the sweat collection, follow the link (the 2025 Australasian guidelines suggest the RCH video https://player.vimeo.com/video/837751686?h=4b12813bf2 – is this appropriate? Should/can we have a local one?)

Sweat analysis

The sweat collected from the sweat test is then tested in the laboratory. The results should be sent to your doctor within two working days of collection. Please contact your doctor for your results.

Important information for carers and parents

• The sweat test has a small risk of causing a minor skin burn. This risk is less than 1 in 50000. These burns are minor and there are no lasting effects.
• In most cases children have shown no sign of pain or discomfort during the procedure. The burns were not discovered until the electrodes were removed.
• Burns are extremely rare with the Elitech iontophoretic system – the system used by ACT Pathology collection centres. This system delivers a very low current using a sophisticated controller. These features reduce, but do not eliminate, the possibility of skin burns.
• Some people may react to pilocarpine in the form of mild redness of the skin (erythema) at the electrode locations. In some cases, one or more blister-like welts may also form. These are often mistaken as burns, but they are simply the skin’s reaction to pilocarpine and will disappear within 2 to 3 hours, leaving no after-effects.

For further information, please contact following ACT Pathology collection centre:

Canberra Hospital Building 10 Collection Centre
Open Monday to Friday from 7.30am to 5.30pm and Saturdays from 8.30am to 12:15pm.
Closed on Sunday and public holidays.
Canberra Hospital, Gilmore Cres, Garran (next to Centenary Hospital for Women and Children
Phone (02) 5124 2816.