What Causes Gout Pain?

[Keith Taylor (GoutPal Admin)]

In a discussion about gout pain

zip2play said:

An aside:

You bring up a point I have always wondered about…Why does every attack in the foot hurt so damned much, but yet tophi tend to readily form in the fingers with little pain, other than a dull ache? Anyone want to hazard a guess?

The fact that they DO grow in the finger joints is no mystery because our fingers are probably even colder than our toes but why painlessly?

---

Understanding gout pain is one of the hardest things, and you can be certain that most doctors do not understand it.

There is an element of what I call physical pain. There might be a better medical term, but I'm referring to what might be called “trauma.” This arises when tophi grow and burst the skin, or joints (bone, cartilage & tendons) erode in the presence of uric acid deposits.

But most gout pain is that caused by an acute gout attack, or gout flare. In this case, pain is inflammatory. We suffer because our immune system reacts to microscopic uric acid crystals, and the inflammation causes pain signals. I've covered this in some depth in my UDRP description of the gout pain pathway. I stress the clear distinction between the myth of pain from “needle-sharp crystals”, and the true explanation of acute gout pain as an inflammatory immune response. Hence my oft-quoted exhortation to ignore anyone who attributes gout pain to sharp crystals in the joints (or sue if you are paying for advice) .

I'm sorry to labor the point for those who already know this, but it is vital that newcomers to gout, who want to understand gout pain, understand what causes gout pain. It isn't a tomato, it isn't a glass of beer, and it certainly is not the crunching and grinding of sharp uric acid needles. Think more in terms of influenza. You hurt because your immune system is crying out for re-inforcements to kill the invaders.

Why does the immune system do this?

Please accept that as a layman, I cannot understand all the intricate processes of cell microbiology that contribute to our expressions of pain. I'll use terms that I understand, and I am happy to receive constructive criticism in ways to explain this better.

Our immune system includes white blood cells (leukocytes), that patrol our bodies looking to protect us from foreign invaders. If it sees a bacterium or something else that shouldn't be there, it tries to kill it. On most occasions, this goes unnoticed. Similarly, with a uric acid crystal, the white blood cell tries to kill it, but it is inanimate, so it settles for enveloping the crystal which is then no longer seen as a threat.

An analogy would be the police patrol. Quite capable of removing the odd bad guy from the scene of the crime, but what about an armed gang, or street riot? Call in the big guys, which is exactly what our white blood cells do. Most have the ability to transform into larger cells (macrophages), which will knock down an invading microbe or uric acid crystal, and call for reinforcements at the same time. A squad of macrophages in your joint is like a SWAT team with Fire Department support in your kitchen. All hell breaks loose – and it hurts.

So the pain level is a question of degree. Most deposits never get a reaction, so you get a slow build up of urate in places where you never had any symptoms. This happens all over the body, until sufficient number of crystals occur in one spot to trigger the panic button. In between the isolated, unnoticed incident, and the uncontrollable riot in the larger joints, there is anything from tingling, numbness, pins & needles, dull aches etc.

The big toe gets it first for most people because it's the most exposed large joint. Elsewhere we've heard from a boat captain who always suffers in the hip because that is the most exposed joint in those circumstances. Different lifestyles present different weak spots.

This also explains why gouties who take the right path, and get their uric acid under control, might have a few months of acute gout flares in previously unaffected joints. Little nests of locked up criminals temporarily freed by the allopurinol purge (or febuxostat/probenecid/lifestyle change purge). We never realized our seedy joints were quite so bad until we had a cleanup – send in the SWAT team.

That's my guess hazarded. Anyone got a better guess?

[Author]

Posts