Allodynia in Fibromyalgia: Why Your Skin Hurts, and What Actually Helps

• About
• Latest Posts

Adam Foster

Director at The Fibro Guy

Adam Foster is the founder of The Fibro Guy and one of the leading voices in hypermobility, EDS, and chronic pain rehabilitation. A former Reconnaissance Soldier, he developed chronic pain after an IED blast in Afghanistan and built his approach from the ground up when the medical system had no answers. Since 2009 he has worked with thousands of people across eight countries, drawing on pain neuroscience, motor learning, and sensorimotor rehabilitation. He co-authored "No Pain, No Pain" with trauma psychologist Dr Mairi Harper, directed the documentary "Invisible Monster," and has been featured in Forbes, BBC Radio 4, ITV News, LiveScience, and The Telegraph.

Latest posts by Adam Foster (see all)

• Hypermobile Neck Exercises - 8 November 2026
• Swollen legs and hypermobility: pooling, lymphoedema and lipoedema - 4 November 2026
• Walking with fibromyalgia - 2 November 2026

Allodynia is pain caused by something that wouldn’t normally hurt ^[1]. The waistband of your jeans, a duvet resting on your legs, a hug, a shower that’s barely warm. In fibromyalgia it often turns up as skin that feels sore, raw or sunburnt with nothing whatsoever to see, which is a hard thing to describe to a GP and a harder thing to have taken seriously.

What allodynia is

The word gets used loosely all the time, so it’s worth defining first. Allodynia is pain from a stimulus that doesn’t normally provoke pain, and it’s usually split into three kinds ^[1].

Static mechanical: pain from steady, light pressure, so a hand resting on your shoulder or the weight of a bag strap ^[1].

Dynamic mechanical: pain from light touch that moves across the skin, like clothing brushing past or somebody stroking your arm ^[1].

Thermal: pain from mild cooling or warming that shouldn’t hurt at all, a cool breeze or a warm bath ^[1].

Its close relative is hyperalgesia, where something that would hurt anyway, hurts far more than it should. A knock on the shin that leaves you reeling for an hour is hyperalgesia, a sleeve brushing your forearm and stinging is allodynia. In real life the two blur together, and we’ve written about hyperalgesia in fibromyalgia separately if that sounds more like you.

Is it part of fibromyalgia?

Pain sensitivity is part of fibromyalgia (as you already know), and the brushed skin kind of allodynia is actually the less typical version of it. When people with fibromyalgia go through careful sensory testing, the most consistent finding is that pressure, heat and cold all start to hurt sooner than they do in people without it, and that holds across the body rather than in just one particular spot ^[2][3]. Pain from a soft brush stroked across the skin shows up in only a minority ^[4][5][6]. So if a tight waistband, a firm grip or the cold gets to you more than a feather would, that fits the pattern better than the textbook picture of allodynia does.

The interesting part is what doesn’t change. How well people with fibromyalgia detect a faint touch, as opposed to being hurt by it, comes out normal or mixed when it’s measured ^[7]. So the touch is being felt about as well as anyone feels it, and the difference is in how much of it arrives as pain.

Why it happens

Every touch starts as a signal from nerve endings in the skin, which travels into the spinal cord and gets passed up to the brain, and at each of those stops the signal can be turned up or down. Central sensitisation is the name for that system running with the volume up, so ordinary input gets passed along louder than it should be. Nobody is imagining anything in that sentence. It’s a change in how the nervous system handles a signal, and there’s a fuller explanation in our piece on central sensitisation in plain English.

The clearest evidence for it is what happens when the same thing is repeated. Press or heat the same spot again and again and the pain climbs with each repeat, which is called temporal summation, and pooling the studies that measured it found a medium sized difference between people with fibromyalgia and people without ^[8]. In the lab, people with fibromyalgia hit that build up at lower forces and lower temperatures, and the pain carries on for longer once the stimulus stops ^[9][10]. That lingering is the bit people recognise, the patch on your arm that’s still sore long after somebody brushed past it.

Brain scanning points the same way. In one of the earliest studies, the same pressure produced far more activity in pain related brain areas in fibromyalgia than in controls, while pressures adjusted so that both groups rated the pain the same produced much the same pattern ^[11]. Put simply, the brain was responding to how much it hurt, and in fibromyalgia it hurt more for the same push. That was also a fairly direct answer to anybody who thought the pain was being exaggerated.

Where the nerves in the skin fit

Small fibre changes are common in fibromyalgia, and they explain less of the skin pain than you’d expect. Small fibres are the thin nerve endings in the skin that carry temperature and the signal from damaged tissue, and they can be counted on a small skin biopsy. Pool the biopsy studies and around half of people with fibromyalgia show some small fibre pathology ^[12]. Having it doesn’t map neatly onto burning pain or allodynia in most studies though, and it seems to mark out a subgroup rather than explain everyone ^[13][14]. Where it does show itself, it’s more through burning, tingling and pins and needles than through pain to touch ^[13][15].

So if burning, tingling or numbness in your hands and feet is the main event, it’s worth asking your doctor whether a small fibre assessment makes sense for you.

Why it burns when there’s nothing there

The skin looks fine because nothing in this process changes how skin looks. The sensation is built further up, out of a signal that’s been turned up on the way through, so skin can feel raw while it looks completely ordinary, and even small fibre changes only show up under a microscope on a biopsy. Burning, as above, is the symptom that lines up best with those small fibre changes ^[13][15].

It moves about from day to day as well, and sleep is the factor with the clearest experiment behind it, although not in fibromyalgia. Cut healthy volunteers’ sleep in an experiment and their pain sensitivity reliably goes up ^[16]. That’s healthy people, so hold it loosely, but it’s the same machinery that’s already running loud in fibromyalgia. If a bad night tends to be followed by a day where your clothes hurt, that fits.

What helps

Treatments can make fibromyalgia less painful overall, and the evidence that they reduce pain to light touch specifically…….. is a lot thinner.

Pregabalin and duloxetine both improve pain and can raise pressure pain thresholds, meaning it takes more pressure before something hurts ^[17][18]. The trials behind that measured overall pain and pressure thresholds rather than pain to light touch, so they can’t tell you how much either one does for sore skin on its own ^[17][18]. We’ve gone through what the duloxetine evidence actually says separately, and either is a conversation for your GP.

Exercise is the more interesting one. Pool the trials and aerobic exercise brings pain down in fibromyalgia ^[19]. Yet a single bout of exercise can make experimental pain worse in people with fibromyalgia ^[20]. Longer programmes don’t reliably bring back the drop in pain sensitivity that usually follows exercise either ^[21]. So start lower than what actually feels worthwhile, build slowly, and judge it over weeks rather than by how you feel that evening. A flare after the first few sessions can be the system behaving the way the lab says it does, rather than proof that exercise is wrong for you, so go slow..

When to get it checked

Allodynia isn’t only a fibromyalgia thing, so a few patterns are worth taking to a doctor rather than filing under fibro. Pain to touch in one patch or down one side, pain that started after a rash, pain alongside numbness or weakness, and pain to touch if you have diabetes all deserve a proper look. Migraine and shingles can both cause it too.

Allodynia is pain from things that shouldn’t hurt, and in fibromyalgia it sits inside a wider pattern where pressure, heat and cold hurt sooner than they should ^[2][3]. A nervous system turning the signal up on its way through has solid support behind it ^[8][11]. Burning lines up best with small fibre changes, in a subgroup ^[13]. Medication is a conversation for your GP, exercise is worth building slowly, and sleep is worth protecting.

Adam

References

[1] Kriek, N., de Vos, C.C., Groeneweg, J.G., Baart, S.J. and Huygen, F.J.P.M. (2023) ‘Allodynia, Hyperalgesia, (Quantitative) Sensory Testing and Conditioned Pain Modulation in Patients With Complex Regional Pain Syndrome Before and After Spinal Cord Stimulation Therapy’, Neuromodulation: Technology at the Neural Interface. https://doi.org/10.1016/j.neurom.2022.06.009

[2] Kosek, E., Ekholm, J. and Hansson, P. (1996) ‘Sensory dysfunction in fibromyalgia patients with implications for pathogenic mechanisms’, Pain. https://doi.org/10.1016/s0304-3959(96)03188-0

[3] Desmeules, J.A., Cedraschi, C., Rapiti, E., Baumgartner, E., Finckh, A., Cohen, P. et al. (2003) ‘Neurophysiologic evidence for a central sensitization in patients with fibromyalgia’, Arthritis & Rheumatism. https://doi.org/10.1002/art.10893