As the name suggests, pseudogout has many of the same symptoms as gout, including the sudden onset of severe pain, swelling, warmth, and redness of the joint. Pseudogout most commonly affects the knee but can occur in any joint, including the ankle, wrist, shoulder, elbow, and thigh. However, unlike gout, it rarely affects the big toe. In this article, we will look at what are and what are the symptoms of pseudogout.
What is pseudogout
This disease occurs when crystals of calcium pyrophosphate accumulate in the joint and cause a reaction of the immune system. Doctors often refer to pseudogout as deposition of calcium pyrophosphate or acute calcium pyrophosphate crystalline arthritis (acute crystalline arthritis). Crystals that cause pseudogout are often found in the joints of older people, but only occasionally do crystals cause episodes of this disease. In fact, one clinical study showed that more than half of the subjects undergoing knee replacement had signs of deposits of calcium pyrophosphate crystals in their joint tissue and that almost none of the subjects who had these crystals knew about them.
Pseudogout is less common than gout and arthrosis and is often confused with gout, arthrosis, or rheumatoid arthritis. Fortunately, the initial treatment for these diseases is very similar, so the diagnosis does not necessarily entail the wrong treatment. Doctors sometimes call pseudogout and gout as “crystal-induced arthropathy,” which simply means that they are joint diseases caused by microscopic crystals. The main difference between the two diseases is the type of crystals that cause the symptoms:
- Pseudogout is caused by calcium pyrophosphate dihydrate crystals, often called calcium pyrophosphate crystals.
- Gout is caused by sodium urate crystals, often called uric acid crystals.
Experts suggest that calcium pyrophosphate crystals are produced in the articular cartilage, and if the cartilage is disturbed through normal wear, damage or trauma, crystals can be released into the joint fluid and other nearby soft tissues. This, in turn, can trigger an acute immune response leading to a short-term episode of severe pain, swelling, redness, and warmth called pseudogout.
Researchers have been aware of calcium pyrophosphate crystals for decades, but still do not fully understand the exact origin of the crystals, or why some people who have them experience episodes of the disease, while others do not. If treatment has not been carried out, the initial episode is usually resolved within 5-14 days. Successive episodes can last longer and can affect more joints. Repeated cases of inflammation can permanently damage the joints over time. This damage is diagnosed as “secondary” arthrosis.
Studies show that people with arthrosis are three times more likely to have precipitation from calcium pyrophosphate. It has been discussed for a long time whether crystals are the cause of joint damage or are the result of joint damage – or both. Scientists agree on the need for additional research in this area.
Symptoms of Pseudogout
When it comes to symptoms, gout and pseudogout are very similar. Both conditions cause pain, swelling, and heat in the affected joint. Pseudogout can also cause redness or purple skin color and also strong tenderness. Both men and women can develop pseudogout, but are more common in women. Pseudogout is also more common in people over 60 years old and in people with thyroid disease, kidney failure, and those who have conditions that affect calcium. It is also common in people with osteoarthritis, which can lead to an erroneous diagnosis if both conditions are present simultaneously.
Many forms of arthritis occur gradually, and in the early stages, a person can only experience occasional mild pain. In contrast, pseudogout strikes are quick, hard and without warning. In fact, the disease can cause such severe pain that the patient believes that this condition is life-threatening.
Typical symptoms of pseudogout:
Affects more joints. Both gout and pseudogout can affect any joint, but pseudogout can affect the knee, shoulder, elbow, ankle, wrist, large joints, thigh, or spine, while more than half of gout cases are associated with the big toe, joint, and heel or with your fingertip.
Pain. The most noticeable symptom of the disease is severe pain in the affected joint.
Swelling. The buildup of fluid in the joint can cause sharp swelling.
Color changes. The skin around the joint and around it may look red or purple.
The heat. The skin around the joint will be warm to the touch.
Stiffness. Swelling and pain can significantly reduce the range of motion of the joints.
Short term. If left untreated, the episode can last from 5 to 14 days, during which the pain decreases. Symptoms of pseudogout are absent between episodes, but consecutive episodes can last longer.
Fever. A person may feel a fever when the immune system responds to calcium pyrophosphate crystals.
Unlike gout, which often strikes in the middle of the night, pseudogout can occur at any time of the day. Another noticeable difference between these two diseases is that repeated cases of pseudogout do not lead to tofus. Tofuses are small white or yellow pieces of uric acid crystals that can be seen through the skin and can be found in people with chronic gout for several years.
Causes of Pseudogout
There is much more that needs to be studied regarding how and why calcium pyrophosphate crystals accumulate in the joints, and why these crystals may or may not ultimately lead to a pseudogout attack.
Known risk factors are listed below:
- Age. Most people who develop pseudogout are over 60 years old, with the likelihood of significantly increased with age. According to the American College of Rheumatology, the prevalence of calcium pyrophosphate crystals increases with only 3% of people aged 60 to 50% of people aged 90 years.
- Joint injury. Joint trauma, surgery, or sepsis can trigger an outbreak of pseudogout.
- Family history. Genetics plays a role, making some people more likely to accumulate crystals in their joints. Recent studies show that a person who inherits a mutation in a gene that helps regulate metabolism is more likely to get the disease and is more likely to develop symptoms of pseudogout at an earlier age than people without a genetic mutation.
The main condition. There are several metabolic and endocrine disorders that can predispose a person to pseudogout, including:
- Hemochromatosis, a hereditary disorder that causes the body to store excess iron in the organs and tissues around the joints.
- Hyperparathyroidism, which can cause abnormal amounts of calcium in the blood.
- Hypophosphatasia, a metabolic disorder that affects bones and teeth.
- Hypomagnesemia, a condition in which there are abnormally low levels of magnesium in the blood.
- Thyroid disease, including hyperthyroidism, hypothyroidism and benign thyroid disease, and thyroid cancer.
- Acromegaly, a condition in which there is too much growth hormone, and body tissues become larger over time.
- Wilson’s disease is an inherited disorder in which there is too much copper in the body’s tissues.
Unlike gout, pseudogout does not seem to be more common in people who are overweight, drink alcohol or drink certain foods. Gender and ethnicity do not seem to affect whether a person will acquire this disease.
Unfortunately, there is no cure for removing or dissolving crystals of calcium pyrophosphate in the joint when they are there. When pseudogout is caused by known conditions such as hypothyroidism, then treating the primary condition can reduce or prevent seizures. However, pseudogout is often idiopathic – meaning the cause is unknown, and treatment focuses on relieving symptoms, rather than on prevention.
By controlling inflammation and other symptoms of pseudogout, the patient can limit the amount of damage done to the joint.
Treatment for pseudogout may include:
Ice. A cold compress applied to the affected joint can help relieve discomfort and reduce swelling.
Rest. It is usually painful to use the affected joint, and rest to relieve pain, swelling and other symptoms of pseudogout.
Height. Raise the affected limb if possible to help reduce swelling.
Puncture. The doctor can aspirate the joint by inserting a needle into the affected joint and removing part of the accumulated synovial fluid. Aspiration relieves pressure in the joint. This treatment is often used with steroid injection.
Corticosteroid injection. A doctor may inject corticosteroids into an inflamed joint to relieve pain. This treatment is especially useful for people who are sensitive to certain drugs.
Oral steroids. If more than two joints are damaged, injections of corticosteroids may become impractical and oral steroids may be prescribed. Oral steroids are also useful if an individual cannot tolerate NSAIDs or colchicine.
Anti-inflammatory drugs. NSAIDs, such as ibuprofen and naproxen, can be used to relieve pseudogout.
Colchicine. If NSAIDs cannot be used or are ineffective, a medicine called colchicine may be prescribed to treat pseudogout. If bouts of pseudogout are more common than several times a year, small daily doses (0.5 to 1.0 mg) of colchicine can be prescribed to prevent attacks. Colchicine has side effects from the gastrointestinal tract, such as vomiting or diarrhea.
Treat the underlying condition. If the accumulation of crystals of calcium pyrophosphate was caused by a fundamental condition, such as hemochromatosis, then the patient should look for specific therapy for this condition. Although existing calcium pyrophosphate crystals in the joint cannot be removed, treatment of the underlying condition can slow the progression of pseudogout.
Surgery. Pseudogout cannot be treated surgically. However, if left untreated, chronic pseudogout can contribute to joint degeneration, requiring surgical repair or replacement.
Older people are more likely to acquire pseudogout, but many older people are sensitive to non-steroidal anti-inflammatory drugs (such as aspirin and ibuprofen), which can relieve seizure pain. In addition, many older people may have additional medical conditions that require medication. To avoid problems with drug sensitivity or drug interactions, doctors and patients often decide that aspiration and steroid injections are the most appropriate treatments for pseudogout.