UDRP:2 Uric Acid Crystals Deposit Category

Gouty tophi are usually noticed under the skin, and are not usually painful until they burst through the skin, or become infected.

Gouty Tophi In Bone

We tend to ignore them in the early stages, and concentrate more on relieving the pain from acute gout flares.

But is this wise?

Probably not now that technology allows us to see tophi growing into cartilage, tendons and bones, leading to bone erosion and severe, painful, joint damage.

Gouty Tophi & Bone Erosion Revealed

It has been a few years since improvements in scanning techniques allowed us to view what is happening inside joints. Over 3 years ago, I quoted from Dalbeth [1]:

There is a strong relationship between bone erosion and the presence of intraosseous tophus. These results strongly implicate tophus infiltration into bone as the dominant mechanism for development of bone erosion and joint damage in gout.

Gouty Tophi & Bone Erosion Reviewed

A significant part of Dalbeth’s, and related research, is the observation that DECT reveals urate deposits much more effectively than any other technique, to the point that joints often show uric acid deposits prior to any physical or inflammatory indication of gout.

There is a commonly held belief that asymptomatic hyperuricemia (high uric acid with no gouty arthritis symptoms) does not need to be treated. This DECT research prompts me to believe that this policy needs to be reconsidered. As I said in my DECT review earlier this year [2]:

Lowering uric acid is more important than generally recognized. The policy of waiting for
several acute gout attacks before commencing urate lowering therapy is outdated, especially
given these clear indications that tendon damage takes place prior to acute gout flares.

Fortunately, this view is beginning to change amongst the more enlightened members of the rheumatology profession. Black and colleagues [3] note:

3D reconstruction clearly conveys uric acid quantity and distribution.

Utilization of imaging studies in order to accurately diagnose, monitor progression or treatment response, and assess clinical outcomes is increasing rapidly

Black’s review includes additional investigation showing benefits in over 50 cases. Note that this study has the diagnostic software to show urate deposits in green, rather than the red selected by most investigators. Many of their cases show clear diagnosis through DECT where traditional techniques have failed.

However, they do add a cautionary note:

Limited initial availability will likely continue the role of DECT to those individuals with diagnostic uncertainty or access to larger imaging centers.

Gouty Tophi & Bone Erosion Restrained

Perhaps the cautionary note is contagious.

It is disappointing to see that whilst recent professional advice recognizes the value of DECT it fails to acknowledge it’s importance as a diagnostic technique, and fails to recognize the implications on asymptomatic hyperuricemia.

Schumacher & Weaver [4] give with the one hand…

Recent studies show that DECT scans reveal signifcantly more areas of urate deposition than a physical examination. [...] But if these newer imaging techniques can identify MSU crystal deposition prior to bone erosion or joint destruction, they offer promise as a noninvasive alternative for diagnosing gout in the earliest stages of the disease. In addition, they may be used in the future to monitor the progression of gout and the effectiveness of ULT.

… but take with the other:

The consensus standard of care today is that asymptomatic hyperuricemia should not be treated.

Perhaps there will come a day when DECT, and other imaging techniques are common enough to dispel the myth that high uric acid is only dangerous when accompanied by acute gout flares. Until then, I recommend you do all you can to maintain your uric acid at a safe concentration below 6.5mg/dL (0.4 mmol/L).

Gouty Tophi & Bone Erosion References

1. Title: Mechanisms of bone erosion in gout: a quantitative analysis using plain radiography and computed tomography. Authors: Dalbeth N, Clark B, Gregory K, Gamble G, Sheehan T, Doyle A, McQueen FM. Published: Ann Rheum Dis. 2009 Aug;68(8):1290-5.
2. Title: DECT For Gout Diagnosis Author: Keith Taylor (GoutPal.com)
3. Title: Dual-Energy Computed Tomography for the Evaluation of Gout and Calcium Crystal Deposits. Authors: Black DF , Glazebrook K , Bongartz T , Matteson EL , Manek NJ , Leng S , Fletcher JG, McCollough C. File: Gouty Tophi Revealed With DECT
4. Title: Core Principles in the Diagnosis and Management of Gout and Hyperuricemia. Authors: Schumacher HR, Weaver AL. File: Gout And Hyperuricemia

Uric acid crystals must be dissolved to permanently get rid of gout pain, but how long does it take to get rid of them?

Like all gouty issues, the answer is never simple. However, we can see some factors that affect the time it takes for crystals to dissolve, and see that the time to start dissolving is now.

In an earlier article, I explained how tophi shrink quicker with lower uric acid concentrations. But this does not mean that once you lower uric acid to a safe level you will immediately stop all gout attacks. In fact, partially dissolved uric acid crystals can start a gout attack, as I explained in Allopurinol Medication: Why It Hurts To Get Rid Of Gout. Though that article looks specifically at allopurinol, the effects of dissolving uric acid crystals might occur with any urate lowering treatment, including diet, until all urate deposits dissolve. But how long does this cleansing period take?
Read the rest of this Uric Acid Crystals article…

Your gout symptoms clear faster with lower uric acid, but how low should you go?

It is very difficult to measure how fast old uric acid crystals are dissolving, but for chronic tophaceous gout sufferers, we can measure how fast their tophi shrink.

Allopurinol for gout has been around for 40 years, and febuxostat is the latest weapon in a growing list of medicines that will lower uric acid. But still people are unsure how low they need to go.
(more…)