Pseudogout

What is pseudogout?

Pseudogout is a form of arthritis (joint inflammation) caused by crystals of a substance called calcium pyrophosphate that form inside the joints. When these crystals shed into the joint space, they can trigger sudden attacks of pain, swelling, and warmth that look very much like gout — which is why the condition earned the name “pseudogout,” meaning “false gout.” The key difference is the type of crystal involved: gout is caused by uric acid crystals, while pseudogout is caused by calcium pyrophosphate crystals.

Doctors increasingly use the broader medical term calcium pyrophosphate deposition disease, often shortened to CPPD, to describe the whole spectrum of problems these crystals can cause. Pseudogout refers specifically to the sudden, painful attacks, but the same crystals can also cause a slower, chronic (long-lasting) arthritis, or they can sit silently in the cartilage without causing any symptoms at all. In the international classification of diseases, pseudogout is coded as M11.20.

So, in answer to the common question “what is pseudogout?” — it is a crystal arthritis, most often affecting the knee, that becomes more common with age. It is rare before age 60 and increasingly common in people in their 70s, 80s, and beyond. Men and women are both affected. Because the crystals often deposit in cartilage for years before causing trouble, many older adults have visible calcium deposits on X-rays without ever developing a painful attack.

Symptoms of pseudogout

Pseudogout symptoms vary depending on which pattern of the disease a person has. The classic picture is a sudden attack in a single joint, but the condition can also behave more like chronic arthritis. Common features include:

• Sudden joint pain — often severe, developing over hours to a day or two
• Swelling of the affected joint, sometimes with visible fluid buildup
• Warmth and redness over the joint
• Stiffness and difficulty moving or bearing weight on the joint
• Tenderness — the joint may be painful even to light touch
• Occasionally a low-grade fever or a general feeling of being unwell during an attack

The knee is by far the most commonly affected joint. Other frequent sites include the wrist, shoulder, ankle, and elbow. This is another point of difference from gout, which most often strikes the big toe. An untreated pseudogout attack typically lasts days to a few weeks before settling, and attacks may return at irregular intervals — sometimes months or years apart.

Symptoms can differ by the type or stage of the disease:

• Acute pseudogout attacks: sudden, intensely painful flares in one or a few joints, as described above. This is the classic form.
• Chronic CPPD arthritis: some people develop persistent, low-level joint pain and stiffness in several joints over months or years. This pattern can resemble rheumatoid arthritis (a chronic autoimmune joint disease) or osteoarthritis (age-related “wear-and-tear” arthritis), which can make diagnosis harder.
• Asymptomatic deposits: many people have calcium pyrophosphate crystals visible on X-rays — a finding called chondrocalcinosis (calcium in the cartilage) — without any symptoms at all. This does not always require treatment.

Because an acutely hot, swollen joint can also be caused by a joint infection, which is a medical emergency, new severe symptoms in a single joint should always be assessed by a doctor rather than assumed to be pseudogout.

Causes and risk factors

The exact reason calcium pyrophosphate crystals form in some people’s cartilage and not others is not fully understood. The crystals develop within the cartilage over time, and an attack occurs when crystals are released into the joint space, where the immune system reacts to them with intense inflammation. Understanding pseudogout causes therefore involves looking at what makes crystal formation more likely.

Recognized risk factors include:

• Older age: this is the strongest risk factor. Crystal deposits in cartilage become steadily more common with each decade after age 60.
• Previous joint injury or joint surgery: a joint that has been damaged in the past is more prone to crystal deposition.
• Family history: in a small number of families, an inherited tendency causes pseudogout to appear at a younger age than usual.
• Certain metabolic and hormonal conditions: these include hemochromatosis (a disorder in which the body stores too much iron), hyperparathyroidism (overactivity of the parathyroid glands, which control calcium levels), low magnesium levels, low phosphate levels, and an underactive thyroid gland. Doctors may check for these, especially in younger patients.
• Osteoarthritis: pseudogout and osteoarthritis frequently occur together, and each may worsen the other.

Attacks are sometimes triggered by physical stress on the body — for example, surgery (including joint surgery), a serious illness, or an injury to the joint. Unlike gout, pseudogout is not clearly linked to diet, and there is no strong evidence that specific foods cause or prevent attacks.

Pseudogout is not contagious, and it is not caused by anything a person did wrong. In most older adults, no underlying metabolic disorder is found, and age-related changes in cartilage are considered the main explanation.

Diagnosis

Because several conditions can cause a hot, swollen joint — including gout, infection, and flares of other types of arthritis — pseudogout diagnosis relies on specific tests rather than symptoms alone.

Joint fluid analysis is the most definitive test. The doctor numbs the skin and uses a needle to withdraw fluid from the swollen joint, a procedure called arthrocentesis (joint aspiration). The fluid is examined under a special polarizing microscope. Finding calcium pyrophosphate crystals confirms the diagnosis, and the shape and optical properties of the crystals distinguish them from the uric acid crystals of gout. The fluid is also usually tested for bacteria, because ruling out a joint infection is essential — infection and pseudogout can look identical from the outside and can occasionally even occur together.

Imaging supports the diagnosis:

• X-rays may show chondrocalcinosis — thin lines of calcium within the cartilage, most often seen in the knees, wrists, and pelvis. X-rays can also reveal accompanying osteoarthritis.
• Ultrasound can detect crystal deposits in cartilage and is increasingly used because it is painless and does not involve radiation.
• Other imaging, such as CT scans, may be used in selected situations, for example when crystals affect the spine.

Blood tests cannot confirm pseudogout directly — there is no single blood marker for it — but they serve two purposes. First, they help exclude other conditions, such as gout (by measuring uric acid, although levels can be misleading during an attack) and infection or other inflammatory arthritis. Second, in many cases, especially in younger patients or those with widespread disease, doctors check calcium, magnesium, phosphate, iron studies, thyroid function, and parathyroid hormone to look for an underlying metabolic cause that may itself need treatment.

Pseudogout is typically diagnosed and managed by a rheumatologist, a physician who specializes in joint and autoimmune diseases. At Acibadem, this condition falls under the care of the Rheumatology Department, often working together with orthopedic and internal medicine specialists when needed.

Treatment options for pseudogout

There is currently no treatment that dissolves calcium pyrophosphate crystals or removes them from cartilage. Pseudogout treatment therefore focuses on two goals: relieving the pain and inflammation of attacks, and reducing how often attacks occur in people who have them repeatedly. Any underlying metabolic condition found during diagnosis is also treated in its own right.

Watchful waiting

If crystals are found on an X-ray by chance and are causing no symptoms, treatment is usually not needed. Your doctor may simply monitor the joints over time and advise you on what symptoms to watch for.

Treating an acute attack

• Joint aspiration: draining fluid from the joint often relieves pressure and pain, and it doubles as the key diagnostic test.
• Corticosteroid injection: after infection has been excluded, injecting a corticosteroid (a powerful anti-inflammatory medicine) directly into the joint is often very effective, particularly when a single large joint such as the knee is involved.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): medicines such as naproxen or ibuprofen can reduce pain and inflammation. They are not suitable for everyone — for example, people with kidney disease, stomach ulcers, or certain heart conditions — so they should be used under medical guidance, especially in older adults.
• Colchicine: an anti-inflammatory medicine long used for gout that can also help pseudogout attacks, particularly when started early. Doses must be adjusted for kidney function, and it can cause digestive side effects.
• Oral corticosteroids: a short course of steroid tablets may be used when injections and NSAIDs are unsuitable or when several joints are inflamed at once.
• Rest, ice, and joint protection: resting the joint and applying cold packs can ease symptoms alongside medication.

Preventing frequent attacks

For people who have repeated attacks, doctors may prescribe low-dose colchicine on an ongoing basis to reduce the frequency of flares. In selected patients with chronic inflammation who cannot use standard medicines, rheumatologists sometimes consider other anti-inflammatory options; these decisions are individualized. Unlike gout, there is no medicine equivalent to urate-lowering therapy that removes the crystals themselves.

Procedures and surgery

Surgery is not a treatment for pseudogout itself. However, when crystal disease coexists with significant joint damage from osteoarthritis, joint replacement surgery — most commonly of the knee — may be considered for the damaged joint, following the same principles as for osteoarthritis alone. Physical therapy can help maintain strength and range of motion between and after attacks.

Treating underlying conditions

If tests reveal a condition such as hemochromatosis, hyperparathyroidism, or low magnesium, treating that condition is important for overall health, although it may not reverse crystal deposits that have already formed.

Living with pseudogout and outlook

The outlook for most people with pseudogout is reasonably good, although the course varies from person to person. Acute attacks, while very painful, usually settle within days to weeks — often faster with treatment — and joints commonly return to their previous state after a flare. Many people have long symptom-free periods between attacks; some have only one or two attacks in a lifetime, while others experience more frequent flares.

Over the long term, repeated inflammation and crystal deposits can contribute to gradual cartilage damage, and pseudogout often coexists with osteoarthritis. This means some people develop persistent joint pain and stiffness over the years. There is no cure, but symptoms can usually be managed, and severe disability is not inevitable.

Practical steps that may help include:

• Staying physically active within your comfort limits to keep joints mobile and muscles strong; low-impact activities such as walking, swimming, or cycling are often well tolerated
• Maintaining a healthy body weight to reduce load on the knees
• Following your doctor’s plan for treating any underlying metabolic condition
• Learning to recognize the early signs of an attack so treatment can start promptly
• Attending follow-up visits so your treatment can be adjusted if attacks become more frequent

Because responses to treatment differ, your rheumatologist can give you a more personal picture of what to expect based on your joints, general health, and how the condition has behaved so far.

Frequently asked questions

What is the difference between gout and pseudogout?

Both are crystal-induced forms of arthritis that cause sudden, painful joint attacks, but they are caused by different crystals. Gout is caused by uric acid crystals and most often affects the big toe, while pseudogout is caused by calcium pyrophosphate crystals and most often affects the knee. The treatments for acute attacks overlap, but gout has crystal-lowering medicines while pseudogout does not, so telling them apart — usually by examining joint fluid — matters for long-term care.

Can pseudogout be cured or go away on its own?

Individual attacks usually do go away, typically within days to a few weeks, and often faster with treatment. However, the underlying crystal deposits in the cartilage remain, and there is currently no medicine that removes them, so the condition itself cannot be cured. Many people still do well, with long gaps between attacks and symptoms that can be managed when they occur.

How serious is pseudogout?

For most people, pseudogout is a painful but manageable condition rather than a dangerous one. Attacks are distressing but usually respond to treatment. In some cases, repeated inflammation contributes to long-term joint damage, and rarely the crystals affect unusual sites such as the neck. The main immediate concern with any hot, swollen joint is making sure it is not an infection, which requires urgent medical care.

What triggers a pseudogout attack?

Attacks often occur without an obvious trigger, but they can follow physical stress on the body, such as surgery, a serious illness, or an injury to the joint. Unlike gout, pseudogout is not clearly linked to diet or alcohol, so specific foods are not considered reliable triggers. If your attacks seem to follow a pattern, mentioning this to your doctor can be helpful.

How is pseudogout diagnosed for certain?

The most reliable test is joint fluid analysis: a doctor removes a small amount of fluid from the swollen joint with a needle and examines it under a special microscope for calcium pyrophosphate crystals. X-rays or ultrasound showing calcium deposits in the cartilage support the diagnosis, and blood tests help rule out gout, infection, and underlying metabolic conditions.

How long does recovery from a pseudogout attack take?

Without treatment, an attack often lasts from several days up to a few weeks. With prompt treatment — such as a corticosteroid injection, anti-inflammatory medicines, or colchicine — many people improve within days. The joint usually returns to how it felt before the attack, although recovery can take longer in older adults or when other joint problems are present.

Does diet affect pseudogout?

Unlike gout, pseudogout has no well-established dietary triggers, and no specific diet has been shown to prevent attacks. A generally balanced diet and a healthy weight are still sensible for joint health. If tests show a related metabolic problem, such as low magnesium, your doctor may give specific advice or prescribe supplements for that condition.

When to see a doctor

See a doctor promptly if you develop new joint pain and swelling, especially if it comes on suddenly or this is your first such episode. A correct diagnosis matters, because several conditions with different treatments can look alike.

Seek urgent medical attention if you notice any of the following red flags:

• A hot, swollen, intensely painful joint together with fever, chills, or feeling generally unwell — this could indicate a joint infection, which is a medical emergency
• A joint you cannot move at all or cannot bear any weight on
• Rapidly worsening redness or swelling spreading beyond the joint
• A joint attack after recent surgery, injury, or a joint injection
• Symptoms that are not improving after several days of treatment, or attacks that are becoming more frequent or affecting more joints
• Side effects from your medicines, such as stomach pain, black stools, or severe diarrhea while taking anti-inflammatory drugs or colchicine

If you have already been diagnosed with pseudogout, contact your doctor when a flare begins, since early treatment often shortens attacks. Ongoing care from a rheumatology specialist can help keep symptoms under control and monitor your joints over time.