Pain in the knees and in any joint are commonly referred as arthritis, but there are different causes of joint pain, which should be diagnosed correctly for proper treatment. One such disease that causes pain in the joint is called as pseudogout. Pseudogout is a type of arthritis that can affect any joint in our wrist, elbow, hip, shoulder, toe, knuckles, and ankle but it commonly affects the knee joint. Unlike gout, which involves the formation of uric acid crystals in the joints, pseudogout is a condition that results due to formation of calcium crystals called calcium pyrophosphate dihydrate (CPPD) in the joints and in the surrounding soft tissues, causing swelling and severe pain in the joints. Pseudogout is often misunderstood for other forms of arthritis like gout, rheumatoid arthritis, and osteoarthritis. In severe condition, pseudogout can result in severe joint-degeneration, progressive inflammation, and chronic (gradual) disability. Pseudogout is also called as calcium pyrophosphate deposition disease.
Causes
The condition pseudogout results when calcium pyrophosphate dihydrate crystals deposit in the cartilage tissue of the joints, and later release in the joint fluid. But the cause of crystal deposition is still unknown although the fact that crystal deposit increases with age is known. Pseudogout commonly affects elderly person, but it can affects young people who have other conditions like
- Hemochromatosis (too much of iron in blood)
- Acromegaly (too much of growth hormone)
- Thyroid disease (increased or decreased hormone production)
- Parathyroid disease (hyperparathyroidism)
- Wilsons disease (too much of copper in the body)
- Ochronosis (presence of acid in urine, which turns the urine brownish-black when exposed to air)
- Less amount of magnesium in blood
- As it runs in families genetic factors are suspected to contribute to the disease
- Other causes of calcium deposit in the body
- Injury, trauma or surgery in the affected joint
Symptoms
The symptoms of pseudogout resemble the symptoms of gout, rheumatoid arthritis, and osteoarthritis. Pseudogout is distinguished from gout by acute attack of synovitis (inflammation of joint) mimicking gout. Pseudogout manifests as sudden onset of severe pain in one joint, mostly the knee joint. This attack lasts for few days to 2 weeks; period between the attacks are usually painfree. It usually attacks one joint at a time, however multiple attacks in various joints are possible. The affected region/joint becomes very sensitive to pressure, and fluid may accumulate in the joint. The joints may have swelling, redness, and warmth, and may be stiff. Some people may also have fever and malaise.
Risk factors
Factors that increases the risk of pseudogout are
- Being old, above 70 years of age
- Previous history of pseudogout
- Hypothyroidism (less thyroid hormone)
- Hemochromatosis
- Less amount of magnesium in blood
- Overactive parathyroid gland that results in increased calcium in blood
- Osteoarthritis
- Diabetes
- Kidney failure
- Joint surgery or injury
Diagnosis
Diagnosis of pseudogout is based on the symptoms and medical tests. Initially the condition is suspected as gout but tests are done to rule out gout. Often, people with osteoarthritis are diagnosed with pseudogout. To confirm pseudogout the following tests are performed.
Fluid from the affected joint is aspirated by inserting a needle into the joint. The fluid is later sent to lab for checking the presence of calcium pyrophosphate dihydrate crystals. An X-ray study can reveal the presence of crystal deposit in the joint and the severity of joint damage. Sometime blood test may be done to rule out the presence of other conditions like gout, rheumatoid arthritis, and osteoarthritis.
Treatment
The goal of treatment is to decrease inflammation and to relieve the patient from pain, still there is no treatment that can relieve the patient completely from CPPD crystals. A fluid aspiration may be required. A needle is inserted into the joint and the fluid from the joint is aspirated out. Then, a corticosteroid drug is injected to reduce swelling and a temporary anesthesia is injected to numb the joint for some time. To reduce inflammation NSAIDs like ibuprofen, naproxen, and indomethacin are prescribed. But NSAIDs cause serious complication in older adults, therefore, discussing these issues with doctor is important. A course of oral steroid may be prescribed in case of multiple joint inflammation. Colchicine is prescribed to patients who cannot take NSAIDs. Colchicine helps to reduce inflammation. Resting the affected joint by minimizing activities, along with medicines, will help to get better soon. In severe cases, where joint degeneration has occurred, surgery to repair or replace the damaged joint is done. Fortunately, as most of the joint pain diseases are treated with same steroids and anti-inflammatory drugs a mistake in early diagnosis does not result in wrong treatment option.
Prevention
There is no preventive rule to avoid the occurrence of pseudogout. But treating the other diseases that increases the risk of pseudogout may help the patient to prevent pseudogout. Take every necessary step to protect joints and avoid stress or pressure on joints.
Outlook
Pseudogout is a very common condition that is often misdiagnosed or misunderstood for other medical conditions. When a patient complains about pain and swelling in the joint doctor’s usually do not consider it as pseudogout. In case of pseudogout attacks following few simple steps like – resting and elevating the affected feet, applying heat to the affected area, and taking few on the counter medicines can help the patient relieve from pain and swelling. As pseudogout is associated with various other medical conditions it is advised that screening should be done in patients with high risk for pseudogout.
