People who can’t go numb from local anesthetic

The people who can’t go numb at the dentist’s – BBC – Jan 1, 2017

I have had problems with local anesthetics, but not dental. I’d love to hear from other people who don’t experience the full effect of anesthetics.

Some people are resistant to local anaesthetic, meaning they must endure dental and medical procedures without such pain relief. And we’re only beginning to understand why.

To Lori Lemon, the doctors all seemed flabbergasted. She had come in to the Mayo Clinic in Jacksonville, Florida, to have a lipoma – a growth of soft fatty tissue under the skin – removed from her elbow. She needed to have the area around the lump numbed for the procedure, but that was proving inexplicably difficult.

All the ways and all the different medications that they had at their disposal – none of them worked,” she says.  

She’d had this problem, local anaesthetic resistance, for as long as she could remember. The first time she remembers it coming up was decades ago at the dentists

He found a handful of stories scattered in the medical literature concerning strange cases where patients claimed local anaesthetic had no effect on them.

Alan Hakim and his colleagues at University College Hospital in London were some of the first scientists to bring these cases to light.

Hakim was helping to run a clinic for people with Ehlers-Danlos Syndrome (EDS), a group of very rare genetic diseases characterised by defects in connective tissue, leading to joint hypermobility, skin that bruises easily and fatigue

But Hakim found that some of these patients reported resistance to local anaesthesia. Instead of going numb, they were having to endure the pain. “It became obvious to us that it was a question we should ask every patient we see in the clinic,” recalls Hakim, who co-authored a short report about the findings in 2005.

One hypothesis is that their tissue is slightly different from non-EDS patients and that might affect how the anaesthetic is absorbed.

Local anaesthetics work by disrupting sodium channels.

These channels conduct positively charged sodium ions – and with them the feeling of pain – to nerve cells.

But there are still some questions over the nuts and bolts of this process.

Filling in the details of that mechanism might explain why some patients find certain drugs – say, articaine instead of lidocaine – work better than others.

One theory proposed for the heightened efficacy of articaine, for example, is that it is more soluble in fat (lipids) and therefore diffuses better through each nerve’s membrane.

It’s also possible that the patients’ nerves may be in slightly different places from the norm, with some evidence that dentists can overcome the problems by changing the location of the injection.

Sometimes local anaesthetic is injected into the tissue under the skin, known as infiltration, and sometimes it is injected into or next to a nerve, what’s called a nerve block.

Hakim says the work done by him and his colleagues has raised awareness among doctors and dentists that local anaesthetic resistance is a genuine problem.

But many today have never heard of it and are sceptical, when first told, that it even exists.

This goes along with the skepticism about pain in general. Because there is no proof, they have to rely on the patient’s word, and they seem more concerned about being fooled by a few than denying pain relief to many.

Some of her patients have told her that their doctor or dentist simply won’t believe them when they say “local anaesthetic doesn’t work on me”.

“I think until there’s that level of proof about it, it’s going to be very difficult to get doctors to accept it,” she says.

‘Missense mutation’

But there’s something else surprising about Lemon’s case: she has never been diagnosed with EDS. Could there be other reasons for her resistance to the anaesthetics?

They asked other members of Lemon’s family whether they experienced the same issue. It turned out that her mother and maternal half-sister shared the apparent resistance, though it wasn’t so pronounced, and yet her father did not.

The next step was to analyse the family members’ genomes. When Clendenen and his colleagues did this, they discovered a genetic defect relating to a specific sodium channel in the body, known as sodium 1.5.

The affected gene, called SCN5A, produces a protein called NaV1.5, which is a major component of this channel.

The type of mutation in question is known as a “missense” mutation, which means that one of the amino acids in the protein is different in people with this genetic quirk.

As a result, the functionality of the protein can be affected. A similar mutation means that people with sickle-cell anaemia, for example, have abnormal haemoglobin – the protein designed to carry oxygen in their blood

A chemical test, however, quickly showed that sodium 1.5 channels were present in peripheral nerves, so a genetic defect related to those channels could – in theory – inhibit anaesthetics in such areas of the body.

It’s not clear what difference is caused by having this mutation, but it could make the sodium channels more likely to remain open, allowing signals to flow to the brain, despite the application of local anaesthetic.

The anaesthetic usually inhibits the flow of sodium and therefore stops a pain signal being delivered from the nerve.

For those who have had to strain through invasive procedures at the doctor’s surgery without pain-relief, or undergo general anaesthetic just to have relatively routine dental work done, there might be fresh hope on the horizon.

“This is really important to get that out there,” says Clendenen.

People don’t believe [these patients] and it’s very frustrating. Even some of my colleagues that I’ve talked to say, ‘I don’t believe it’.

Because of my problem with local anesthetics, I’ve become very apprehensive about medical procedures. Among people with EDS, this is not uncommon, but I didn’t know that earlier in life and suffered a few terribly painful procedures.

I wrote about this in KevinMD: When impossible pain is, in fact, possible

After they inject their “foolproof” local anesthetic, what doctor would believe my complaint of pain when they know I can’t feel anything?

I’d love to hear from others who have had such issues…

I also posted articles that show a link with hypermobility, the genetic basis for this, and my own experience:


93 thoughts on “People who can’t go numb from local anesthetic

  1. Diana

    I have the same problem with local anaesthetic not working during giving birth through C-section. I had been given three times anesthesy before operation because I still felt everything, but by the time I got on the operation bed it worn off and started to feel it again. In short, the Csection op had complications, the anaesthesist tried different anaesthetic three more times, but didn’t work, so he said he cannot give me anymore. I went into triple shock (pain, loss of blood and too much anasthetic), seizures and fainted a few times but still felt everything and heard everything when coming around. Worringly, my baby slept continously for more than 24 hours and couldn’t wake him up, but they saud is because the anaesthetuc they give me. Never been diagnosed with EDS, never heard of it, but here the doctors don’t take you seriously that you are in pain unless they SEE something wrong, like you have a broken bone or something.

    Liked by 1 person

    1. Zyp Czyk Post author

      What an awful story! I’m surprised you were able to survive literally being cut open without being anesthetized – it’s unimaginable to me.

      It’s also the first time I’ve heard of this happening to someone who doesn’t have EDS. You don’t mention if perhaps you might have it but just haven’t been diagnosed. This would be a symptom to help within EDS diagnosis if you ever seek it out.


  2. Lexi

    I’m so glad to find others with this problem, I would say I’m resistant not immune to localized anesthetics. I’ll go ‘numb’ but I never completely lose feeling and it wears off really really quickly. Even when I had my baby the epidural did not even come close to completely numbing me, I retained full control over my lower extremities and bladder the whole time and I felt every stitch when they were stitching me back up (couldn’t be more than 20 min. After the epidural was placed) and then I was up and walking right after. Dentists maybe have a 5 min window where the anesthetic kind of works, when I had surgery on my toe they tried to numb it so many times my toe was swollen twice it’s size with fluids and I could still feel it. Glad to know I’m not crazy.

    Liked by 1 person

  3. Richard

    Hi I know this is old however thought I would let you know that I am resistant to local anaesthetic, have been all my life. Dentist and doctors have tried and failed. I have had dental work done, stitches and ingrown toenail removed with the doctor giving me 6 injections and it still failed. It was certainly numb but I could feel everything.

    Liked by 1 person

    1. Zyp Czyk Post author

      I assume you also have EDS? I’m lucky that the dental anesthetic works ok at high doses, but the lidocaine they use for stitches and topical procedures fails completely.

      I thought I was imagining things until I read about this and, now that I know, I’ll mention it to any doctor that needs to give me local anesthetic. I’m pretty sure there’s more than one kind…


  4. Michelle

    I had my lungs tapped with a huge needle to drain the fluid off of my lungs due to heart failure. I felt the entire 30 minutes of the procedure as lidocaine and other local anesthesia’s do not work for me. This was an excruciating experience.

    Liked by 1 person

    1. Zyp Czyk Post author

      Did you already know your condition made you “immune” to local anesthetics before this procedure and is this the horrible way you found out?


  5. Sharon Crowder

    I totally understand the frustration. I have this same problem and doctors don’t believe it. It’s simply torture going through a biopsy or other invasive procedures without any relief. I hope that doctors will start believing their patients and help find a solution instead of turning a blind eye on us.

    Liked by 1 person

    1. Zyp Czyk Post author

      It took me quite a while to understand that others achieved numbness when I only got partial or no relief. It didn’t occur to me until I read about our (Ehlers-Danlos) resistance to local anesthetics that I put together all the “unpleasant” medical treatments I’d endured.

      At least now there’s enough medical evidence to support our claims to feel pain despite local anesthetic – we’re not just being sissies



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