When Even a Light Touch Hurts

Even the brush of clothing hurts.

When people first hear this, most assume it is an exaggeration. The patients themselves doubt their own words. "Maybe I'm just being oversensitive."

It is not oversensitivity. Medicine has a name for this phenomenon. Allodynia — a state in which a stimulus that should not be painful is felt as pain. And it is a very real pain.

Why does something that shouldn't hurt, hurt?

The skin has several kinds of sensory nerves. Some nerves carry pain, others carry light touch. These signals are sorted once in the spinal cord before they travel up to the brain.

Normally, touch signals are conveyed as touch, and pain signals as pain, each separately.

But when pain signals keep coming up for a long time, a problem arises at the sorting stage in the spinal cord. The pain circuit becomes excessively sensitive, and it starts to read even the neighboring touch signals as pain.

• The circuit widens, so even a small stimulus is conveyed as large
• The boundary between pain and touch blurs
• Even after the injured place has healed, only the signal remains

In this state, painkillers do not work well. Painkillers usually calm the inflammation at the painful spot, but the problem is not at that spot — it is in the circuit that reads the signal.

But it is not a problem of the circuit alone

This is where many explanations stop. They give it the name "central sensitization" and use nerve stabilizers. Sometimes these help.

I ask one step further. Why was that pain signal continually coming up in the first place?

For a circuit to become sensitized, there must be something that has been sending signals for a long time. As long as that source remains, calming only the circuit will soon let it come back.

A case I saw

There was a patient who suffered from allodynia on the front of the thigh. It hurt so severely to be touched by hand that she was using a narcotic pain patch.

There was nothing wrong with the thigh. The imaging was normal too.

I pressed on the abdomen. The pressure in the lower abdomen was abnormally high, and the ligament in one groin was unusually taut and hardened. This was the spot where the nerve and blood vessel that run down to the front of the thigh pass through.

A compressed nerve keeps sending signals. When that signal continues for several months, the circuit in the spinal cord becomes sensitized. And from a certain point, it begins to read even a light touch as pain.

Without forcing the hardened tissue open, I gradually softened and released it, lowering the tension in that area. Then the pain in the thigh dropped to less than half. I never even touched the thigh.

So I approach it on two fronts

When I deal with allodynia, I look at two things at the same time.

First, I cut off the source of the signal.
I look for the spot where the nerve is compressed, where the pressure has risen, where things have hardened and stopped moving. It is usually somewhat away from where it hurts. If I do not release this, the circuit keeps being stimulated.

Second, I turn the sensitized circuit back.
This takes time. A nerve circuit can weaken just as it strengthened, but not overnight. It needs continuous input. Something that keeps working during the hours away from the treatment room — this is where herbal medicine has a role to play. And the experience of moving without pain must be inscribed back into the circuit.

Either one alone is not enough. Cut off only the source and the circuit remains; soothe only the circuit and the source stimulates it again.

Being honest about time

Allodynia did not arise overnight. So it does not resolve overnight either.

Recovery does not come in a straight line; it comes while going back and forth between better and worse. I look, together with the patient, at how much less bad the worse days have become rather than at the better days. If the troughs of the waves are getting shallower, the direction is right.

The patient I mentioned did not heal all at once either. Being cut in half was the beginning.

Finally

Allodynia has many causes. Cases where the nerve itself is damaged, cases that remain after shingles, cases where the nerve has been harmed by diabetes, and cases where the cause is never found. I do not claim that finding a compressed spot explains all allodynia.

When needed, I first recommend a neurology consultation or detailed testing. There are certainly times when painkillers and nerve stabilizers are needed.

But to those who have been told "the tests are normal, yet even a light touch hurts," I want to say clearly at least this much: it is not a matter of oversensitivity. The signal is coming up from somewhere. I will look for that spot with you.