Gout can be divided into two types, namely tophaceous gout and pseudogout. While there are characteristics that make these diseases seem similar to each other, further inspection proves that there are differences between the two.
Tophaceous gout (or chronic tophaceous gout) occurs when gout attacks or flare-ups become more frequent at short intervals, without resolving the inflammation during this period.1 This type of gout results in the formation of lumps of white or yellow3
Elderly women have a higher risk of developing tophi compared to men, and people who have had an organ transplant or are taking cyclosporine also have higher chances of being affected with tophi.4
On the other hand, pseudogout (or calcium pyrophosphate deposition disease [CPPD]) is a type of arthritis wherein one or more joints are affected with excruciating swelling, in episodes that last for days or even weeks.5 This similarity with gout is why it’s called “false gout.”
Apart from the pain-causing crystals (which will be discussed further), certain situations can predispose you to a higher chance of having pseudogout. These include old age, dehydration and hormonal effects on calcium metabolism from hyperparathyroidism.6
The Difference Lies in the Crystals on Your Joints
A major difference between these two diseases lies in the type of crystal that’s seen in the joints. Tophi that come from uric acid are found among tophaceous gout patients, but for people with pseudogout these crystals form because of calcium pyrophosphate.
Each type of crystals has its own distinct features that can be determined when the joint fluid that houses the crystals is viewed under a microscope.7
The periods when the symptoms of this disease appear aren’t the same, either. Tophaceous gout is the last of the four stages of gout, and the disease progresses over a long period of time, such as 10 years, especially when you do not take measures to alleviate the sickness in the first place.8
Meanwhile, symptoms of pseudogout are often felt long before you’re even diagnosed with the disease, because of gout attacks wherein your joints become swollen, warm and extremely painful.9
Patients May Experience Different Types of Pain as Well
The discomfort that results from these diseases also vary in terms of severity. When it comes to tophaceous gout, the aching in your joints tends to be more severe since it has already affected your body for a longer period of time. Your kidneys may even be affected as well.10
This isn’t to say that pseudogout is less harmful. You’ll still feel pain because of gout attacks, but they won’t be as harsh. What both tophaceous gout and pseudogout do have in common are the areas of the body that will be most affected — the joints. Tophi common in tophaceous gout are found around your fingers and your big toe, forearms,11 tips of your elbows, ears, and vocal chords.12 Meanwhile, your knees, ankles, wrists, shoulders and hips are the major points where pseudogout can strike.13
There are rare cases wherein tophi are spotted around the spinal cord and the heart, and instances of tophi breaking through the skin resembling crab eyes were also reported. While tophi are typically painless, they can cause discomfort and stiffness in the affected joint.
If not addressed, these crystals can cause wear-and-tear on your cartilages and bones, and destroy your joints. Large tophi seen under the skin of your hands and feet can lead to severe deformities as well.14