Published online Sep 18, 2022. doi: 10.5312/wjo.v13.i9.870
Peer-review started: July 11, 2022
First decision: August 1, 2022
Revised: August 7, 2022
Accepted: August 25, 2022
Article in press: August 25, 2022
Published online: September 18, 2022
Processing time: 66 Days and 13.4 Hours
Calcium pyrophosphate dihydrate deposition disease (CPPD), or pseudogout, is an inflammatory arthritis common among elderly patients, but rarely seen in patients under the age of 40. In the rare cases presented of young patients with CPPD, genetic predisposition or related metabolic conditions were almost always identified.
The authors report the case of a 9-year-old boy with no past medical history who presented with acute knee pain and swelling after a cat scratch injury 5 d prior. Synovial fluid analysis identified calcium pyrophosphate dihydrate crystals. Further MRI analysis identified osteomyelitis and a small soft tissue abscess.
This case presents the extremely rare diagnostic finding of calcium pyrophosphate dihydrate crystals in a previously healthy pediatric patient. The presence of osteomyelitis presents a unique insight into the pathogenesis of these crystals in pediatric patients. More research needs to be done on the role of CPPD in pedia
Core Tip: Calcium pyrophosphate dihydrate deposition disease (CPPD) is rarely seen in patients under the age of 40. This case represents a rare diagnostic finding of CPP crystals in a 9-year-old patient. Previously, the youngest patients ever described in case reports were 16 years old. In the rare cases presented of young patients with CPPD, genetic predisposition or related metabolic conditions were almost always identified. In this case, the presence of osteomyelitis presents a unique insight into the pathogenesis of these crystals in pediatric patients. This case highlights the need for more research on the pathogenesis of these crystals and their role in pediatric arthritis and joint infection.