Calcium pyrophosphate deposition

Reducing diagnostic delay in hypophosphatasia: a case series of 14 patients presenting to general rheumatology

OBJECTIVES

Hypophosphatasia (HPP) is a rare genetic metabolic bone disease that can cause chronic pain and fractures. Its hallmark is a persistently low serum ALP. HPP is now recognised by many osteoporosis specialists, but other specialists, such as rheumatologists and primary care physicians, may be less aware of this condition, causing diagnostic delay and possible harm to these patients. Our objective was to highlight features that can reduce this delay.

METHODS

We retrospectively analysed 14 patients that presented with musculoskeletal pain to general rheumatology clinic at St. George's Hospital and were subsequently diagnosed with HPP.

RESULTS

Median diagnostic delay was 13 years. All patients had an ALP below reference range for age and gender, with lowest mean ALP of 16 IU/L. All but one patient were women with median age of 51 years. Most common presentation was peripheral joint pain in 85.7% of patients. This was due to early-onset CPPD (calcium pyrophosphate deposition disease) in 71.4% of patients, osteoarthritis in 50%, or bursitis in 50%. Axial pain was reported in 64% of patients due to osteoarthritis or spinal stenosis. Fifty percent of patients had a history of long bone pain. Fifty percent had previous fracture(s). A total of 28.6% of patients had psoriatic arthritis, of which 1 patient had spondyloarthropathy, and 4 patients also had enthesitis.

CONCLUSION

Patients with HPP can present to rheumatology with musculoskeletal pain, and if a persistently low ALP is confirmed, this may reduce the diagnostic delay of this rare disease. Similar to other rheumatologic patients, musculoskeletal pain in HPP was noted in peripheral joints and in the spine with almost a third of patients having psoriatic arthritis. Pain was also noted in the long bones, a feature consistent with metabolic bone disease. The diagnosis of HPP was also more likely in those patients with a personal or family history of dental disease or arthritis.

Calcium pyrophosphate deposition disease: The role of imaging in their detection and in differential diagnosis of crystal arthropathies

Calcium pyrophosphate deposition disease is characterized by the deposition of pyrophosphate crystals in various joint structures. Calcium pyrophosphate deposition disease can be linked to underlying metabolic disorders such as hemochromatosis, hyperparathyroidism, hypophosphatemia, hypomagnesaemia, and hypothyroidism, all of which increase the risk of calcium pyrophosphate deposition. We present the case of a 55-year-old male who underwent diagnostic examination for the onset of recurrent joint pain in the right knee.

Acute calcium pyrophosphate deposition arthropathy

Acute calcium pyrophosphate deposition (CPPD) arthropathy, also called pseudogout, is common, and becomes more prevalent as patients age. The presenting symptoms are similar to both gout and septic arthritis but may be treated differently. This article describes a typical patient presentation and management from an emergency medicine and orthopedic surgery standpoint.