Are false faint positive LFTs a thing?

[yelloweverything]

Dd11 had a faint positive LFT today. It was barely there in the time slot (not everyone in the house could see it) but after the time elapsed, it was a bit stronger (but still faint). We've all gone for PCRs waiting for the results.

I was in the camp that a positive LFT meant likely positive PCR but I've known a few people in the last few weeks where PCR has come back negative after faint positive LFT - is it a thing now? Is it happening a lot?

I'm slightly clinging on to hope here as we have a lot of lovely things that will have to be cancelled at great upset to SEN dd who already has mental health issues from the covid / lockdowns etc taking so much away from her. Timing at its absolute worst.

Yes. Often they start feint and are more obvious when testing again days later. Need PCR to confirm.

@Flanjango

Yes. Often they start feint and are more obvious when testing again days later. Need PCR to confirm.

We've had a PCR done today - waiting for results to come back.

Presumably a PCR today would still pick it up on the same day as a faint LFT?

Every lateral flow that I've known to be positive has eventually resulted in a positive PCR. Some have been the next day, some have taken several PCR results before showing up.

If her line was really faint this morning then it's possible it's too early for a PCR to show as a positive. I'm really sorry as isolating is rubbish, but a line on a LFT in my experience means Covid.

I'm having this with my ds. Both ds and dd tested positive on lft dd pcr was sent Wednesday and still haven't had results yet but ds did his Friday and his is negative....how? He's had 7 positive lft. I've now apparently got to send him school. His school is strict and will certainly expect him in. His lft were faint then got darker as time went on and dd was strong to begin with and she has symptoms. After all them lft what am I to do if the school want him in. It's a Sunday so I can't ring until tomorrow and they don't open until 8 which is when he has to set out for school I'm just so so confused.

This is what worries me.

What if it comes back negative - do we accept it? Or keep testing over and over again because it's likely a positive LFT should mean positive PCR? I don't know anyone who has - they've accepted the negative and got on with their week.

Dd has no symptoms and will not cope with the ongoing uncertainty / more testing.

It's so confusing.

I had a very faint grey positive lateral flow. Pcr was negative and I kept testing and never had another positive so I think mine was genuinely false, I think more than one positive ltf and certainly if lines start getting stronger and darker you need to go by the lateral flow result . I think if you are recording lateral flow results each time you get a positive lateral flow you're told to isolate till your pcr result so that will cover you for school even if it means you have to keep going for pcrs .

I had a very faint positive lateral flow, went for a PCR and was positive. Next day, negative lateral flows!

Possible I just picked up a positive at the end of having covid (hadn’t tested for just over a week before the positive) but nevertheless! My results did take a day and a half, and my friend who tested ten minutes before me at the same test centre got her results in 12 hours, but that’s probably just coincidence!

I'll test tomorrow and ring the school because I know it'll be positive again and see if they want me repeat the pcr but as its negative they might want him I'm. I just don't understand it. I feel so uncomfortable sending him in with positive tests but they're so strict.

Dd had two faint positives in the same day. Followed by a negative PCR and another negative PCR a few days later to be sure. She only had a sore throat and coughed a handful of times in one day.

The rest of us were absolutely fine. (We also had negative PCRs).

No idea what that was about.

@iggly did she go into school in between the pcr?

My DS had two faint LFT positives a week apart, both times followed by negative PCRs. He then had a strong LFT positive about 3 weeks later and did have covid that time (confirmed by PCR), so obviously didn't have it 3 weeks before so they were genuine false positives. I'd trust the PCR result when it comes.

[quote Vanillacupcake33]@iggly did she go into school in between the pcr?[/quote]
No, it was half term. We isolated until the second one came back.

My lft looked negative within the time frame then when I went to throw it away a couple of hours later it had a faint positive line. Did another and it was negative, then the PCR was also negative

Well PCR came back positive anyway.

Dd is devastated (not because its covid) because it ruins everything planned. She's had a lot of mental health problems following a lot of loss from the pandemic and is very much struggling.

My DD had a very faint line. We did two more and one looked negative and the other was faint again.

PCR was positive though.

Sorry to hear that, OP. We had the same thing with dd - the faintest line on a ltf that was barely even there. PCR came back positive and dd subsequently developed symptoms that hadn't been there when she tested. Thankfully they were mild!

It's difficult for your dd to have to miss out. We were relatively fortunate with the timing of ours, but even then, 10 days of isolation seemed like the end of the world to my very extroverted dd. Can you plan some lovely things for the post isolation period to try to make up for what she has missed and to give her some stuff to look forward to?

Thanks @AlexaShutUp we will try. She has SEN so her thinking isn't always as clear as it could be. She's really had a rough deal through the pandemic and I've all the times to get it, this week is the worst.

I am really sorry for her. I hope you can rearrange it all.

@yelloweverything sorry about your dd. I hope she gets well soon.
My ds is still testing positive on lft so I've kept him off and I'm going ring nhs in a bit but I know his school isn't going to be happy but I just don't see how he's still testing positive with a negative pcr. If the nhs tell me go by this pcr and the school want him in I'll have no choice but to send him school but it just seems so wrong. My dd is suffering with her symptoms shes getting very strong positives but it's been 6 days since I did her pcr and it isn't back but I'm fully expecting that to be positive. I just don't know what to do with ds.

My husband has had three positive lfts and negative pcrs.

Make sure they leave a gap after eating/drinking, especially anything acidic like fruit/juice. My oh got a false +ve lft that way (just eaten an apple)

I've normally done them first thing in the morning. Just spent best part of an hour on 119 and on hold 3 times. They've advised it could have been too early for the pcr to pick up so they would recommend self isolate and repeat pcr. I rang the school who were not happy at all and wanted him in but then said to stay off and repeat pcr Thursday as he's had so many positive lft. As for my dd her test results are delayed and I have to class as covid as she has symptoms and strong positives and she needs to continue isolating.

@candycane222

Make sure they leave a gap after eating/drinking, especially anything acidic like fruit/juice. My oh got a false +ve lft that way (just eaten an apple)

With a nasal only one? The newer ones are nasal swab only

Ah paedon me, we're still working oir way through the last nose-and- throat ones here. Don't get out much!

@candycane222

Ah paedon me, we're still working oir way through the last nose-and- throat ones here. Don't get out much!

I ditched the throat ones once I realised we could get nose only. So much better (not as tickly 😂)