Pseudogout
Jill C. Cash and Julie Barnes
Definition
A.An acute inflammatory condition primarily affecting the larger joints in which crystal deposits of calcium pyrophosphate dihydrate (CPP) occur in the connective tissues.
Incidence
A.Acute attacks occur more often in men than in women.
B.Women diagnosed with osteoarthritis (OA) with CPP have a higher incidence of occurrence.
C.Approximately 50% of cases occur in patients older than the age of 84 years, 36% occur during the ages of 75 to 84 years, and 15% occur in those from 65 to 74 years old.
D.Joints affected: The knee is affected approximately 50% of the time; other joints affected include wrists, shoulders, ankles, feet, and elbows.
Pathogenesis
A.Pseudogout occurs from the crystal formation in the cartilage that is shed into the synovial joint. Excessive cartilage pyrophosphate production leads to calcium pyrophosphate production and CPP crystals are formed and deposited in the joint.
Predisposing Factors
A.Older adults.
B.Joint trauma.
C.Hospitalization/illness.
D.Familial chondrocalcinosis.
E.Endocrine/metabolic disorders:
1.Gout.
2.Hyperparathyroidism.
3.Hemochromatosis.
4.Hypophosphatasia.
5.Hypothyroidism.
6.Hypomagnesemia.
7.Gitleman’s syndrome.
8.Hemosiderosis.
Common Complaints
A.Asymptomatic (may be visible on x-ray).
B.Acute attack of pain and swelling of affected joint, commonly a large joint.
C.Erythema.
D.Decreased range of motion (ROM) secondary to severe pain; inability to bear weight.
Other Signs and Symptoms
A.Fever.
B.Pain, swelling, and redness in several joints.
Subjective Data
A.Ask the patient about the onset, progression, and duration of symptoms.
B.How many joints are affected?
C.Is this the first time this has occurred, or is this a chronic problem?
D.Ask the patient to describe the onset of symptoms, in the order of occurrence.
E.In addition to today, has this occurred in other joints?
F.Does the patient have a history of rheumatoid arthritis (RA), OA, or other types of arthritis?
G.Any previous injury to the joint?
H.What has the patient used for pain or fever?
Physical Examination
A.Check vital signs, temperature as indicated.
B.Inspect:
1.Inspect the affected joint for erythema, edema, and synovitis.
2.If erythema is present, note location of erythema and evaluate if erythema extends beyond joint area.
3.When examining the joint, note facial grimaces, guarding with examination.
4.If weight-bearing joint is affected, note if the patient is able to bear weight.
C.Auscultate:
1.Lungs and heart
D.Palpate:
1.Palpate affected joint, noting pain and swelling in the joint.
2.Assess ROM in joint if possible.
Diagnostic Tests
A.Complete blood count (CBC).
B.Erythrocyte sedimentation rate (ESR).
C.Serum C-reactive protein (CRP).
D.Comprehensive metabolic profile (CMP).
E.Magnesium level.
F.Thyroid-stimulating hormone (TSH).
G.Iron studies (iron, total iron-binding capacity, ferritin level).
H.Joint aspiration for synovial fluid. Microscope: Synovial fluid evaluation for crystals.
I.X-ray of joint: Results may demonstrate linear and punctate calcifications in articular hyaline or fibrocartilage, also known as chondrocalcinosis.
Differential Diagnoses
A.Pseudogout: Joint aspiration of synovial fluid recommended for diagnosis. Diagnosis made by crystals identified by polarized light microscopy or radiographic changes of CPP crystals noted in the tissue or synovial fluid.
B.Gout.
C.Septic arthritis.
D.RA.
E.OA.
Plan
A.General interventions:
1.Acute attacks should be treated with rest, immobilization, and education.
2.Differentiate between acute and chronic attacks and treatment.
3.Recurrent attacks should have long-term management.
B.Patient teaching:
1.For acute attacks, encourage rest and elevation of affected joint.
2.Encourage no weight bearing until symptoms subside. Suggest the use of crutches or cane for assistance.
3.Warm, moist compresses may be used as needed for comfort.
4.As symptoms improve, suggest ROM exercises for affected joint.
5.Once symptoms have improved, weight-bearing activities may resume.
6.Symptoms should continue to improve over the next 7 to 10 days. Full recovery should be expected.
C.Pharmaceutical therapy:
1.For acute attack, with one to two joints affected and no signs of infection:
a.Large joints (knees/shoulders). Joint aspiration and glucocorticoid steroid injection: Triamcinolone acetonide 30 to 40 mg mixed with 1% procaine, 1 to 2 mL. Smaller joints require less steroid.
2.If not meeting the criteria discussed earlier, the next treatment option recommended is the use
of nonsteroidal anti-inflammatory drug (NSAID) medications:
a.Naproxen (Naprosyn) 500 mg twice a day with food.
b.Indomethacin (Indocin) 50 mg three times a day with food (not recommended in high-risk patients with heart failure, GI effects, or decreased renal function).
c.Sulindac 200 mg twice a day with food.
3.If NSAIDs are contraindicated, use colchicine 1.2 mg within 24 hours of attack, followed by 0.6 mg 1 hour later, then 0.6 mg BID.
4.If injection and use of NSAIDs are contraindicated, use oral prednisone 30 to 50 mg daily until flare begins to resolve, then taper prednisone over the next 7 to 10 days.
5.Recurrent attacks (more than three attacks in 1 year) should be treated with colchicine. Monitor liver and kidney function. Consult with physician and/or refer to rheumatologist.
Follow-Up
A.The patient should return to the office in 48 to 72 hours after diagnosis and treatment.
B.Patient follow-up in 1 week is recommended for continued care.
C.If symptoms are not improving or are worsening, patient should return to the clinician’s office or present to the emergency department for further evaluation and treatment.
Consultation/Referral
A.Refer all patients who appear to have a septic joint to the emergency department for evaluation and treatment. Refer to an orthopedic surgeon for consult.
B.Consider referring patients with pseudogout to rheumatology for evaluation and continued care.
Individual Considerations
A.Adults:
1.Most commonly seen in adults older than 60 years.
2.Precautions should be used in treating patients with long-term NSAIDs. Active GI ulcers or history of GI disease should avoid NSAID use.
3.Patients on blood thinner medications should avoid the use of NSAIDs.
4.All precautions for the use of NSAIDs in adults should be considered, including chronic kidney disease.
5.Patients diagnosed with diabetes who are prescribed oral or injection steroids should be advised that steroids may increase blood sugar and to monitor blood sugar values at home as indicated.
B.Geriatrics:
1.Most common in the older adult.
2.Precaution should be used with using NSAIDs in the older adult.
3.Monitor renal function.