My ds is 5 & has asthma & chronic sinusitis. He is also small for his age (5% wt/10% ht). He was over 9 lbs at birth & had some difficulty gaining weight in the first few wks, but gained well until the ear infections and wheezing started around 5 m & he slowly started falling down on the growth charts. He had tonsils & adenoids removed at 4 along with sinus surgery for a chronic infection that would not clear. 1 yr later his sinuses are really bad again despite aggressive treatment. Our ENT is very well respected and treats a lot of cf kids. He said the lining of our ds's respiratory tract does not work properly causing abnormally thick, sticky mucous (based on his observations during surgery & the pathology reports). His opinion is that our ds "looks like" what you would expect a child with undiagnosed cf to look like (small for size, asthma, sinus problems, and frequent stomach aches). His bms do not look greasy but they do frequently float. He was sweat tested at 3-1/2 by our allergist & it was negative (10). Our pulmonologist (with a cf clinic) said that the test was valid and that it was unlikely that he has cf. We are waiting on the results of genetic testing. I'm just wondering if anyone has any experience with cf despite a negative sweat test? Is that possible? If so, does anyone have any links or experience with it? Thanks!
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Is it possible to have a negative sweat test & still have cf?
- Thread starter Sunshine
- Start date
It is possible but a score of 10 is really low. Most negative sweat tests that turn out to be CF are in the 30's, 40's. The symptoms are similiar to CF. The "floating stool" really bothers me.Do his fingers/hands/feet prune quickly when bathing? Most people with CF have this happen. If he "prunes" up in less than 3 minutes I would strongly encourage you to aggressively rule out CF. The genetic test, tests for 85% of the CF mutations. It can also be negative and your son have CF. There are over 800 different CF mutations, the genetic test looks for about 100 of the most common. Best wishesDon P
Don, Thank you for your reply. In answer to your question, no he doesn't prune up quickly. At least not any quicker than me! Both our pulmonologist and allergist said the same thing that you said regarding the genetic testing. Our allergist also wants our ENT to consider testing him for an immotile cilia disease? I am of course hoping that it is just asthma, allergies, and reflux contributing to his sinus problem. The ENT's comments do really bother me though, especially since he discussed cf in great detail (approx 10 min of our appt). Our allergist and pulmo both think he probably doesn't have it just based on the sweat test but our pulmo also said he really respects our ENT's opinion because he treats a lot of the pulmo's cf kids and that it does need to be discussed in more detail. The genetic test should be back in another week or two and we see our pulmo at the end of the month to discuss the results and what, if anything needs to be done. Thank you for your comments.
Hey it seems to me that the quickest thing to do while waiting on the genetic tests is to re-test for CF. It wouldn't be the first time that a sweat test came back wrong. Make sure it is done at the CF center not at a "local" hospital since CF centers have a better track record than other places with sweat tests. From what you posted, I gather that your pulmo deals with CF, is he in a CF center? (it sounds like CF even without the positive sweat test, but I hope it isn't) Good luck Andrea
Andrea, thanks for your reply. Actually, our family dr asked the same thing you did. She also does not honestly think he has it because he's never had any hospitalizations and in general, all flare ups (with the exception of the sinuses) are usually treatable with xopenex and antibiotics, prelone if needed (he's on nasal steroid sprays, inhaled steroids, singualir & prevacid). But, she is planning to call our ENT and discuss it with him. She's going to call if she thinks we need to redo the sweat test. Our dd also has asthma, allergies, eczema, and a severe nut allergy. She was sweat tested because of the asthma and recurring pneumonias (5 in one year). Her sweat test was also low like our ds. Our dr thinks thats a good sign. Our dd is well controlled now and our dr thinks we just need to figure out how to get our ds controlled as well. I really do hope that's all it is but am scared just the same. On the sweat test, the nearest cf center is 3 hrs away (where our pulmo is from). The hospital we had the testing at was trained by the cf center and is accredited. But, I guess if we do have to retest, it would probably be best to have it done at the cf center. I will ask about it. Thanks!
Sunshine,I have to share my story with you. My daughter now 7 years old. Has been very sick since birth. I have taken her from doctor to doctor. At birth(6 weeks preemie) the doctors told me she would not live one day. Dispite their predictions she is here today. Her lungs were not developed, her eyes were not developed, she was anemic and had 2 blood transfusions, she had sleep apnea and bradicardia, and juandice, just to name a few. She had very rough start. At 1 year, she stayed so sick, the doctor says asthma and allergies. She was started on the nebulizer with Xopenex and Albuterol. This continued 2 doctors later. At age of 3, she visited allergist. She had no allergies. He believed it to be CF. Sweat test was low positive (42 & 45), DNA for 18 mutations was inconclusive. 2 doctors later and at 4 years, we were told asthma. Then I started getting tired and she was much worse than a year or two before, I demanded a chest x-ray on one of her sick visits. I was not satisfied with the answers I was getting. Low and behold, she had full blown pnemonia that could not be heard through the stethescope. We were finally sent to a pulmonologist. He did more CF tests. Out of 4 sweat tests, 3 were positive ( 2 still low, but one at 60). Another DNA test was done. It was inconclusive at 87 mutations. At this point, I was despirate. My daughter was keeping pnemonia. The pediatrician was telling me to keep doing what I was doing or take her to an emergency room. And that she knew it was CF and there was nothing she could do for her. She landed in the hospital last year with pnemonia again and dehydration to the point that her veins were collapsing. She was only 39 lbs. at 6 years old. Had alot of vomiting up mucus. They found that was caused from severe reflux. She was set up with the vest therapy system when she left the hospital (which has helped her alot). So,after that stay I changed doctors again. This time he has diagnosed her CF, worked with the schools, and gotten her set up to visit the local CF center on a monthly basis. But here was the SHOCKER... the first visit we saw an absolutely wonderful doctor with very high credentials. He did another DNA test for 900 mutations, highest available. And did other blood work. Next visit he tells me, there is NO WAY she could have CF. I wanted to know what it was since she had all the symptoms and 5 doctors told me they believed that was what it was. Well he knew. Blood work showed she had no antibodies to pnemonia in her body. He gave her a vaccination. We are praying this could be so simple. She still will have to be tested for other antibodies to other diseases. But come to find out, the damage to my daughters lung from birth was allowing the mucus to build just like CF. And in time it will have to be removed. I pray this is not what is wrong with your child. I don't wish CF on anyone. But remember one thing, presistance pays off!Susansnrgrave@bellsouth.net
I see no reason to repeat a sweat test with a score of 10. If it were to double it would read 20 (which is 1/3 of the positive range) Unless the sweat test were totally botched it is unlikely you will get a CF diagnosis by that test at this time.Based on the "floating stool" comment, I would do a fecal fat test. They test the stool for unabsorbed fat.I think your doctors are doing the right things.Hang in thereDon P
I was tested at birth (the hospital was testing every baby for CF at the time) and it came back negative. My parents didn't have any reason to believe I had CF and I was very healthy till about 8 or so. Long story short I was retested 14 years later and I found out I had CF...the most common mutation too. I am happy to say that at 19 and am very healthy adn going strong. I would demand tests and make sure docs have ruled CF out 100% even if that means retesting (at a CF center)
Thanks everyone for your help. Don, I do have a question about the fecal fat test. My ds had this as an infant and everything was fine. Can someone who has been absorbing correctly suddenly stop? I do plan to discuss that with our pulmo at the end of the month. Susan, our allergist is actually testing our ds for antibodies to vaccines. He had the prevnar vaccine at 2 yrs but our allergist said that pneumoccocal bacteria are common culprits of recurring sinus problems so he is testing for antibodies. Ds had a basic immune workup at the same time as the sweat test but his levels were all normal except IgE which apparently is an indicator of asthma, allergies, and eczema, all 3 of which he has/had. We will have those results probably at the same time as the genetic tests. I think the thing that is so difficult is that all of our drs are disagreeing on what they think is the *most likely* reason for his problems. Our family dr thinks it's just his asthma, allergies and use of antihistamines (I don't buy that because we have only used them a few times since his surgery), our ENT thinks cf and our allergist thinks an immune problem or cilia problem. Since we haven't seen the pulmo yet, I'm not sure what he thinks. Another thing that bothers me with our ds is that he frequently coughs MORE right after his pulmicort or xopenex treatments. If you ask him, he tells you he feels like he's choking. And, the other thought that has been bothering me lately is that if, on the off chance, he truelly does have cf, that would make it quite likely that our dd does, too. I mean, if he has a mutation that causes low sweat test results, her sweat test results would not be meaningful either, right? Although her asthma is pretty well controlled now, her asthma flares almost always involve lots of chest congestion, rattling, and crackling and almost always require 1 or 2 rounds of antibiotics although she may go several months between flares. Well, either way, hopefully we will get some answers soon. Thanks everyone for listening to my obsessive ramblings!
Hi,Some people are able to absorb normally for a while, It depends on how much mucus blocks the passage between the pancreas and the intestines. My daughter did fine with her digestion for the first few months but some with CF can go years without having a problem. Some never need to take enzymes at all( not common though) Can I ask if your son brings up "stuff" when he coughs after a neb treatment? Like sticky mucus or anything? If the cough sounds wet he might be bringing up mucus. If he is, try having him lean over and clap his back to make it easier to bring up the mucus. (have tissues ready though) up and out is better than not coughing it out.The reason i suggested re-doing the sweat test was because it could be wrong. These things happen even at good CF centers.good luck to you and keep us postedAndrea
Thanks everyone for your advice and suggestions. We finally got the results of the genetic testing and ds did not have any of the 87 mutations tested for. I know it's still possible that he could have cf but since both the genetic testing and sweat test were negative, we are considering him negative!! To the poster that mentioned the pneumococcal titres, we also got that testing back and he did not have the response that you would expect from the prevnar so we are vaccinating with the pneumovax and retesting. Also, Andrea, thanks for your suggestion. Actually ds had been doing really well and had stopped coughing after pulmicort so I was not able to try it until recently. His sinuses and ears are in bad shape right now so he's coughing again but did not bring anything up. Thanks again everyone for your advice. Good luck to all of you!!
Thanks everyone for your advice and suggestions. We finally got the results of the genetic testing and ds did not have any of the 87 mutations tested for. I know it's still possible that he could have cf but since both the genetic testing and sweat test were negative, we are considering him negative!! To the poster that mentioned the pneumococcal titres, we also got that testing back and he did not have the response that you would expect from the prevnar so we are vaccinating with the pneumovax and retesting. Also, Andrea, thanks for your suggestion. Actually ds had been doing really well and had stopped coughing after pulmicort so I was not able to try it until recently. His sinuses and ears are in bad shape right now so he's coughing again but did not bring anything up. Thanks again everyone for your advice. Good luck to all of you!!