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Calcium pyrophosphate deposition disease (pseudogout)



Musculoskeletal system


Pediatric musculoskeletal conditions
Musculoskeletal injuries and trauma
Bone disorders
Joint disorders
Muscular disorders
Neuromuscular junction disorders
Other autoimmune disorders
Musculoskeletal system pathology review

Calcium pyrophosphate deposition disease (pseudogout)


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High Yield Notes
15 pages

Calcium pyrophosphate deposition disease (pseudogout)

9 flashcards

USMLE® Step 1 style questions USMLE

2 questions

A 64-year-old woman comes to the physician complaining of pain in the right knee for the past day. The patient reports associated joint swelling, warmth, and redness. She says this has happened before in her knees and hips, but those episodes lasted for only a few hours and resolved spontaneously. She also reports feeling fatigued during the past several months, but attributes this to frequently waking up at night to urinate. The patient has also had to strain more than usual when having a bowel movement and frequently takes laxatives to help. Vital signs are within normal limits. Physical examination reveals swelling, erythema, and warmth of the right knee joint. It is tender to palpation with decreased active and passive range of motion. Laboratory studies show the following:

Arthrocentesis of the right knee is performed. Gram stain is negative. Polarized light microscopy shows rhomboid-shaped, weakly positively birefringent crystals. Further evaluation of this patient is most likely to show which of the following?

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External References

Calcium pyrophosphate deposition disease (CPDD), also called pseudogout, is a type of arthritis that occurs when calcium pyrophosphate dihydrate (CPP) crystals build up in the joints. This can lead to pain, stiffness, and swelling in the affected joints. CPDD is often mistaken for gout, another type of arthritis that is caused by the deposition of uric acid crystals in joints.

CPDD most commonly affects middle-aged and older adults. It tends to run in families, so you may be at higher risk if you have a close relative with the condition. There are two types of CPDD. The most common type is primary (idiopathic) CPDD, which occurs when calcium deposits build up in the joints for no known reason. There is also secondary CPDD, which is caused by another preexisting condition that leads to calcium deposit formation, such as joint trauma, osteoarthritis, and hyperparathyroidism.

Symptoms of CPDD may present acutely or develop slowly over time. The most common symptom is pain in the affected joint, ranging from mild to severe. Commonly affected joints include knees and wrists, but they can also affect ankles and hips.