Cystic Diagnosis Part 4: Sweat Test at the CF Clinic

Sweat Test machine at McMaster

The clinic at Mac was fantastic. The CF test itself is pretty archaic, but, apparently, it’s also extremely accurate. They refer to Mac’s test as “the gold standard”. And, I’ve been told that if you get a CF test, McMaster is the place to get it. Other hospitals do the test, but, even if their results come back positive, they still send you to McMaster to “make sure”. The test involves measuring the amount of salt in the patient’s sweat. It goes like this:

1. They clean the person’s forearm with alcohol or some other cleaning material.
2. They put a metal plate about the size of a credit card on the arm. They connect this metal plate to a big battery-sized device that looks like a radio from WWII. This machine sends an electrical pulse through the arm, stimulating it and making it sweat. This happens for approx 5 minutes.
3. They take the plate off and they put a piece of sterile gauze on the arm, cover it with a plastic bandage and wrap the whole thing in a towel and tape the towel over the arm.
4. You go hang out for a 1/2 hour, while the arm sweats and the sterile gauze soaks it up.
5. Go back into the clinic room where they take the gauze off and send it off for testing.
6. Done. Pretty simple.

NOTE: none of this is uncomfortable for the child. At most, the person will wonder why the plate is buzzing on their arm.