Cystic Fibrosis Questions - Sweat Testing
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Sweat Testing
Jul 01, 2010 at 2:38 PM

My son was diagnosed with CF through newborn screening.  Recently, my aunt and I had discussed how her daughter (my 1st cousin) was constantly sick with chest infections, and she has to use a neb for breathing treatments often.  She's only been able to play with my son a few times since he's been born because she always seems to have a 'chest cold' and we're afraid she will make him sick. 

She decided to ease both our minds that she would mention that there is a family history of CF to her pediatrician.  Sure enough, he sent her to have a sweat test today.  The lab isn't equiped to run the test there, so it had to be sent off to another lab.  But the technician said that she was 99% sure she didn't have CF because when you sweat test someone with CF their sweat 'beads up' and sticks together, and that her's didn't.   I had never heard this before, and I don't want my aunt to get her hopes up.  Have any of you heard this?  I'm not sure how long it will be before she gets the results, but I'm praying it's negative.

I kiss on our sweet son often. I first noticed that MY lips tasted salty all the time. I can't think of one mama that knows anything about CF that wouldn't/hasn't kissed her baby's forehead to see if it's salty. It finally dawned on me that maybe I was getting the saltiness from the baby. So, I wiped my mouth and then kissed on that baby! It was him. He was salty. But, I blew it off as motherly paranoia. Plus, I couldn't even remember the name of the disease with which the saltiness was associated. If someone had told me CF was it I still wouldn't have put it together because I thought of CF as only a lung disease. Our boy is extremely salty. His sweat test numbers were 1.16, 1.17, 1.23, and 1.25. Pretty darn salty! You can taste it.

Another thing that I had noticed before his diagnosis, that I understand now and have researched, is the aquagenic palm wrinkling that can happen with CFers. Our boy would get so pruned in the pool, tub, and shower. I thought it was just something unique to him. However, it is associated with CF. Our boy can simply wash his hands and he starts to wrinkle. Keep his hands in water for over a minute and he's pruning quickly. Within two to three minutes his hands look like mine would after thirty to forty minutes. We have five children so it's easy to compare their palms and saltiness. This might be something your cousin could try. NOT to diagnose her! But, it would be one more symptom on the side of CF. I also would suggest an accredited CF clinic for the sweat test.
Jul 22, 2010 at 11:53 PM
ya carin iv licked girls and some of them have been salty all im sayin is that it isnt a definate way off knowing
Jul 02, 2010 at 3:55 PM
Brandy- It will be interesting to know the results. I know a 65 year old CF researcher who diagnosed himself at 19. He was one of the Scientists who discovered that there was a salt chloride issue amongst Cf'ers.
Jul 01, 2010 at 11:33 PM
Brandy, Check into whether the lab that the test was sent to is an accredited CFF clinic/lab to make sure the test was done correctly and sodium chloride was measured correctly. I have never heard anything about the actual beading of the sweat to be any indicator.

Yes, Carin! When Lucy was just 2 days old still in the NICU, not even diagnosed with CF yet (nor did we know we were carriers) her skin was SO incredibly salty. Her toes, her forehead, her entire body was salty! It burned my chapped lips! Without knowing anything about CF at the time, I thought it was incredibly weird, so I mentioned it to her doctor because I WAS the only one to ever kiss my baby all over. Along with the meconium ileus and salty skin, it was then that CF was first discussed.

This is the 18th century German saying:

"Woe is the child kissed on the brow who tastes salty, for he is cursed and soon must die."
Jul 01, 2010 at 10:58 PM
Yeah don't let your aunt get her hopes up. There is a possibility it is not cf, but don't go by an old wives tell type thing to say whether something is or isn't there.

I don't know how you can't tell the difference in what beads up and what doesn't. Sometimes mine beads up and sometimes it doesn't. Might depend on how much sweat is there too.

Also keep in mind it is very easy to get a false negative too. They are easy to get if they technicians didn't do it right. So even if it comes out negative, she might want to get a genetic test just to be extra sure.
Jul 01, 2010 at 10:11 PM
Hey Chad! We live in Jacksonville, FL. We moved from Miramar/Pembroke Pines this past fall. How are you making it down there? Jacksonville is hot, but I could barely stand it when I lived that close to the equator.
Jul 01, 2010 at 9:41 PM
Brandy, good luck to you and your family. I asked a million questions while my son was getting his sweat test and they never mentioned anything regarding the appearance of the sweat. All they said is that they needed enough sweat to activiate a blue dye within the vial that would indicate an ample amount of sweat. I hope that the technician is right. But, I don't think that my son's sweat looks any different than anyone elses .. it just tastes very salty.

I would like to add to Carin's thoughts for a moment. I have two children, one with cf and one without cf - After we got the phone call to go in for John Riley's sweat test, my mom confessed to me that she licked his forehead and he tasted extremely salty. I didn't believe her at first and finally decided to try for myself. I licked his forehead and later my daughters forehead. (They wanted to test her since he was positive and I got scared.) There is a tremendous difference. I am not saying that is for everyone, but it is the case for my children too. We live in Florida and it is hot as balls .. he sweats everytime we go outside. Everytime I lick my lips, I taste salt because I am always kissing him. I never experienced that with my daughter - even on the hottest day.
Jul 01, 2010 at 8:47 PM
All the sweat test does is measure how many salt ions are present in a known amount of perspiration. Of course, everyone has salty sweat, but people with CF are saltier. That is exactly how they diagnose people. If you score above a certain level of sodium in your sweat(I believe about 60mm/ml), you have tested positive for CF. I'm sure you are not the only mother who has licked her child's forehead. I don't call Brady my little salty dog for nothing! When healthy kids go outside and get sweaty, they stink etc... When Brady really gets going, he will have salt crystallized under the rim of his hat and on his groin area when I take off his diaper. I've heard adults with CF who are runners complain that the super salty sweat dripping in their eyes can be a real pain in the butt. The entire disease of CF is based on improper transport of salt. The sweat glands contain epithelial tissues that are affected by this imbalance as well. I also read in an article about the History of CF that in medieval times, when you kissed a baby's forehead and it tasted salty, it was thought to be under an evil hex...soon to die. Go figure.
Jul 01, 2010 at 8:46 PM
Willie- have you ever compared a Cf'er and non-Cf'er by licking their forehead? You would be able to tell the difference. I have a 17 month old w/ CF and a 3 month old w/o CF.

I am surprised more people are not aware of the salty forehead as an indicator. I never mentioned anything about kissing someone w/ CF or not...I just mentioned a way to determine if a child has CF while waiting for results..a good indicator,

Jul 01, 2010 at 7:54 PM
im sorry but people with out cf can have salty sweat as well so it isnt a hugh indicator
Jul 01, 2010 at 6:24 PM
We knew we were carriers of CF and did a lot of research before K was born...licking the forehead and it being salty will be a huge indicator.
Jul 01, 2010 at 6:20 PM
yes, from her being sooooooooo salty. That is the way they used to be joke.
Jul 01, 2010 at 6:18 PM
Amanda, I think she was just commenting on how salty her skin was. Nothing to be taken out of context.
Jul 01, 2010 at 5:59 PM
Carin, I knew when I kissed Drew that he tasted salty too. It wasn't the doctor, just the lab worker collecting the sweat that made the comment. But I had never heard that before, and like Rebecca said, I didn't think there was any difference in CF sweat and regular sweat. The thing is, in my rural area I doubt the technician had even collected sweat from a CF patient, unless it was part of her training because I can't think of any other CF patient in my area other than my son, (and he didn't have his test done at this hospital.) It's not a CF clinic doing the sweat test, it's just a local hospital collecting it, then they're sending it out for processing. I just don't think the technician should make comments like that until the results are back. My cousin is 7 years old, and has always been very sick with congestion problems. Until now the docs have always said it was bronchitis, or pheumonia, etc. But I finally got her to mention the fact that her 1st cousin has CF to her pediatrician, so he decided to test. I'll let you know when the results are in. Like I said, I'm not sure how long it will be because it had to be sent off to another lab for the processing.
Jul 01, 2010 at 5:57 PM
lol. i think with that comment, your page is gonna get outta control with responses, and not in a good way. sorry
Jul 01, 2010 at 5:49 PM
u cant be serious saying you licked her forehead and knew, you cant diagnose like that ha
Jul 01, 2010 at 5:48 PM
Im sorry but is that a joke or are you serious Carin?
Jul 01, 2010 at 5:32 PM
She will know if she licks her forehead...I knew we were carriers and when my daughter was born, I licked her and knew she had CF...She tasted like a Payday bar!
Jul 01, 2010 at 4:40 PM
There is no chemical reason why CF sweat should "bead" together. The only difference between "normal" sweat and "CF" sweat is the increased level of Sodium ions.
Jul 01, 2010 at 4:07 PM
That is very intresting. I have never heard about the sweat beading up. It dosent make since to me because there r a lot of people that get diagnosed with CF later on in life. I think a lot of people have different symptoms when it comes to CF, not everyone is the same. Maybe she has a very mild form? Please keep me posted, I will keep her in my prayers.
Jul 01, 2010 at 4:01 PM
Ive never heard of this. Like, the sweat on the body beads up?
Jul 01, 2010 at 3:34 PM
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