Gout and pseudogout are arthritic diseases where crystalline deposits collect in the joints, leading to pain, stiffness, redness, and swelling. Although the symptoms of gout and pseudogout are similar, the underlying causes are different. The buildup of crystals in gout is triggered by elevated levels of uric acid, while pseudogout is caused by a buildup of calcium pyrophosphate dihydrate.
In general, men are more likely to suffer from gout, and women are very slightly more prone to pseudogout. Both conditions are common in the elderly, with pseudogout often affecting a knee, while gout usually affects a big toe.
|Joint Symptoms||Arthritic joint pain, swelling, redness, warmth, and extreme tenderness. In some cases, the development of tophi||Arthritic joint pain, swelling, redness, warmth, and extreme tenderness. Acute onset more common, but chronic condition possible.|
|Treatment||Resting the joint and applying ice, NSAIDS, corticosteroids, colchicine (a painkiller), medications that target uric acid production or excretion, healthy diet low in purines (from alcohol, meat, fish).||Resting the joint and applying ice, NSAIDS, the painkiller Colchicine, corticosteroids. Healthy diet may help, but it not as strongly associated with pseudogout symptoms.|
|Diagnosis||Imaging tests, drawing fluid from the swollen joint for analysis, blood tests||Imaging tests, drawing fluid from the swollen joint for analysis, blood tests.|
|Cause||Hyperuricemia — overabundance of crystalline monosodium urate (uric acid) deposits in the blood and joint fluid.||Chondrocalcinosis — abnormal buildup of crystalline calcium pyrophosphate dihydrate (CPPD) deposits in joint cartilage and fluid.|
|Commonly Affected Joints||Affects the joint in the big toe in about 50% of all cases, but may affect heels, ankles, knees, wrists, and/or fingers, too.||Most likely to affect a knee joint first, but may also affect wrists, ankles, shoulders, and/or other joints.|
|Length of Symptoms||Usually 5-12 days, but prolonged or chronic attacks may occur over time.||Usually 5-12 days, but prolonged or chronic attacks may occur over time.|
|Prevention||Difficult to prevent. A healthy diet, exercise, and proper diagnosis and treatment of any other problems may help. Some evidence that low-fat dairy and coffee lower risk of gout.||Difficult to prevent. A healthy diet, exercise, and proper diagnosis and treatment of any other problems may help.|
|Occurrence||More common after age 60. Men of any age and post-menopausal women have higher uric acid levels, as do black people. More common in those who are obese and/or have heart, kidney, or blood pressure problems.||More common after age 60. Women slightly more likely to develop pseudogout than men. Often comorbid with other joint disorders.|
Symptoms of Gout and Pseudogout
Differentiating between gout and pseudogout by symptoms alone is difficult, if not impossible, in most cases. Both disorders cause acute arthritic attacks that include the following common symptoms:
- Burning/aching pain in and/or around the joint
- Reddening or purpling of flesh at the pain site
- Swelling and stiffness
- Warmth at the pain site
- Extreme tenderness
Which Joints Are Affected?
While gout and pseudogout can technically affect any joint, they tend to affect specific joints, particularly during the first arthritic attack. Pseudogout is most likely to affect the knee joint first, but may also affect wrists, ankles, or shoulders. Gout affects the joint in the big toe in about 50% of all cases, but it may affect heels, ankles, knees, wrists, and/or fingers, too.
How Long Symptoms Last
There are acute and chronic forms of gout and pseudogout. Acute cases may be infrequent but more painful. Chronic cases may be inconvenient but less painful or even painless over time. This does not mean someone experiencing symptoms should not get diagnosed and treated, however, as untreated gout can lead to a number of health complications.
How long an acute arthritic attack lasts can vary from person to person. Most gout and pseudogout attacks will clear up in 5 to 12 days, but the length of an attack may increase with age and last for weeks or a month, or, as mentioned, become a chronic condition.
What Causes Gout and Pseudogout?
The most significant difference between pseudogout and gout is the underlying causes of pain. Both disorders are caused by crystalline buildups in the joints that fall under a category of inflammatory arthritis known as crystal arthropathy. While gout is caused by an overabundance of crystalline monosodium urate (MSU, or uric acid) deposits in the blood and joint fluid, pseudogout is related to the abnormal buildup of crystalline calcium pyrophosphate dihydrate (CPPD) deposits in joint cartilage and fluid.
CPPD buildup is known as chondrocalcinosis, and elevated uric acid levels are known as hyperuricemia. Age is one of the biggest factors in developing either — a majority of the elderly population has one or the other, or both — but only some cases of chondrocalcinosis or hyperuricemia ever result in a pseudogout or gout attack.
Gout is moderately better understood than pseudogout. Uric acid is produced when purines, which exist in the body and in foods, are metabolized. When the body later fails to metabolize uric acid or, alternatively, fails to filter it through the kidneys, gout can be the result.
Because gout is at least partially associated with obesity and diets heavy in meat, fruit sugar (fructose), and/or alcohol (particularly beer) — all foods and drinks that were once, and sometimes still are, a luxury only the wealthy could afford — gout is sometimes called "the rich man's disease." But diet is only one possible reason a person might struggle with gout, and it usually is not the only reason.
Certain ages and sexes are at higher risk for getting gout or pseudogout. Joint trauma (e.g., caused by surgery), medications, a family history, and other medical conditions can play a role in the development of these conditions as well. Diabetes, metabolic disorders, and kidney disorders or failure are related to both gout and pseudogout, and underactive or overactive thyroid and mineral imbalances, particularly of iron or magnesium, are specifically related to CPPD buildup in cases of pseudogout.
Symptoms are not enough for a doctor to differentiate between pseudogout or gout with confidence. Several tests can be performed to determine what is causing joint pain.
- Blood tests can reveal the high level of uric acid and/or creatine in the blood, indicating gout, or the mineral imbalances and/or thyroid problems associated with pseudogout. Blood tests are rarely the only type of testing performed, though, as many people with high levels of uric acid do not experience gout, just as many people with pseudogout may not have mineral imbalances or thyroid problems.
- Fluid drawn from the arthritic joint can be analyzed microscopically for the presence of urate crystals (needle-shaped; yellow when parallel to the axis, blue when perpendicular; strongly refractive, or birefringent, under compensated polarized light) or CPPD crystals (rod-like; blue when parallel to the axis, yellow when perpendicular; weakly refractive). This test can clearly determine whether gout or pseudogout is the cause of an attack. It cannot, however, determine if any other health problems are playing a part in the inflammation. Synovial fluid tests, as these tests are called, have the added benefit of potentially relieving pain and pressure from the affected joint.
- Imaging tests, like X-rays, ultrasounds, and CT scans, enable doctors to study the inflammation so they can determine whether the presence of any crystals is caused by gout or pseudogout, and whether the inflammation is influenced by other types of arthritis.
There is no cure for either form of arthritis, but medications can be used to treat symptoms and reduce the severity of inflammatory attacks. With gout, lowering uric acid levels is key. In contrast, treating pseudogout may be more complex, depending on any underlying conditions (e.g., hyperthyroidism).
- Resting the joint and applying ice to the pain site are two of the simplest methods of reducing pain without introducing new side effects.
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as over-the-counter Advil (ibuprofen) and Aleve (naproxen), can be used to treat the minor to moderate pain of a gout or pseudogout attack. More powerful prescription NSAIDs, such as Celebrex (celecoxib), may also be used. Unfortunately, frequent, continued use of these medications can lead to stomach pain, ulcers, and/or bleeding.
- Colchicine is a prescription painkiller used specifically for pseudogout and gout. One downside to this drug is its common side effects, including nausea, vomiting and diarrhea. Instead, this drug is often prescribed at a very low dose to prevent future arthritic attacks in those who frequently suffer.
- Corticosteroids (e.g., prednisone) can be taken in pill form or injected directly into joints to reduce inflammation. As with all steroid drugs, however, frequent use can come with significant side effects, such as mood swings and hypertension.
- Medications that target uric acid production and excretion in the body may be prescribed for gout sufferers who experience several attacks a year. These drugs — xanthine oxidase inhibitors and uricosurics — reduce uric acid production or increase its excretion, decreasing the number of attacks. Commonly prescribed drugs include allopurinol, febuxostat, and probenecid. Overall, though, these drugs are rarely prescribed, as they can lead to other health complications, like reduced liver function or kidney stones.
- A healthy diet can help with any illness, but it may be especially beneficial for gout sufferers, who are told to limit their intake of alcohol, fructose, and foods high in purines (e.g., meats, seafood, and beans). At least one study has found that eating cherries may reduce the number of gout attacks on experiences.
In the case of gout, failure to treat long-term, elevated uric acid levels can result in kidney damage and the development of tophi, hard nodules of crystals that sometimes come to the surface of the skin.
Because gout and pseudogout are largely associated with age, prevention of these disorders is difficult, if not impossible. Further complicating matters is the fact that doctors are not yet sure why only a fraction of those with uric acid or CPPD buildups ever experience an arthritic attack.
As is the case with most illness prevention, a healthy diet, exercise, and proper diagnosis and treatment of any other health problems will likely go a long way to preventing gout and pseudogout.
Age is a big factor in the development arthritic disorders. Most people will not develop either of these conditions until after the age of 60, but it is possible to develop them between the ages of 30 and 60 as well.
Men have higher levels of uric acid and are more likely to develop gout than women until around age 50, when women tend to develop menopause, at which point women's uric acid levels increase to a level similar to men's. Gout is also more common in blacks than in whites due to genetic factors. Meanwhile, pseudogout affects men and women almost equally, with women only being very slightly more likely to suffer from pseudogout.
Gout has become more common in places like the U.S., where diets, obesity, hypertension, and alcohol consumption increase the chance of developing the disease. In general, people who struggle with other illnesses or obesity are at higher risk for pseudogout and gout. And pseudogout is frequently coupled with osteoarthritis and other joint disorders, increasing the importance of proper diagnosis.
- Arthritis and Pseudogout - WebMD
- Coffee consumption and risk of incident gout in men - NIH.gov
- Eating cherries lowers risk of gout attacks by 35%, study suggests - ScienceDaily
- Effects of dairy intake on hyperuricemia and gout - NIH.gov
- Gout Definition - Mayo Clinic
- Gout Overview - WebMD
- Pseudogout Definition - Mayo Clinic
- What are purines and in which foods are they found? - The World's Healthiest Foods
- Wikipedia: Gout
- Wikipedia: Chondrocalcinosis