View source for Crystal arthritis

__NOTOC__
{{Crystal arthritis}}
{{CMG}} ; {{AE}} {{ADG}} {{Cherry}}

==Overview==
Crystal induced arthritis is a relatively common condition that involves deposition of crystals in [[Joint|joints]] and soft tissues. A variety of [[Crystal|crystals]] can deposit in and around [[Joint|joints]] and soft tissues, resulting in [[articular]] and periarticular inflammation. [[Urate|Monosodium urate (MSU)]] and [[Calcium pyrophosphate|calcium pyrophosphate dihydrate (CPPD)]] are the most commonly involved crystals in the pathogenesis of crystal induced [[Arthropathy|arthropathies]]. Other rare types of crystal arthropathy include [[Hydroxylapatite|hydroxyapatite]] crystal deposition [[arthropathy]]. [[Gout]] and [[Pseudogout|pseudo-gout]] manifest with similar symptoms, and cannot be distinguished clinically.  [[Synovial fluid]] analysis the involved joint is essential to diagnose and differentiation of crystal induced arthropathies. 

==Causes==
Common causes of crystal arthritis include:

*[[Gout]]
*[[Pseudogout]] ([[Calcium pyrophosphate|Calcium pyrophosphate dihydrate]])
*[[Calcium apatite deposition disease]]

==Classification==
{{Family tree/start}}
{{Family tree | | | | | | | | | | | | | | | | | | | | A01 | | | | | | | | | | A01=Arthritis}}
{{Family tree | | | | | | | | | | | | | | | | | | | | |!| | | | | | | | | | |}}
{{Family tree | | | | | | | | | | | | | | |,|-|-|-|-|-|^|-|-|-|-|-|.| | | | |}}  
{{Family tree | | | | | | | | | | | | | | B01 | | | | | | | | | | B02 | | | | |B01=Inflammatory|B02=Non-Inflammatory}}
{{Family tree | | | | | | | | | | | | | | |!| | | | | | | | | | | |!| | | | }}
{{Family tree | | | | | | | | |,|-|-|-|-|-|+|-|-|-|-|-|.| | | | | C01 | | | |C01=Osteoarthritis}}
{{Family tree | | | | | | | | C02 | | | | C03 | | | | C04 | | | | | | |C02=Rheumatoid factor|C03=Infectious|C04=Crystalloid }}
{{Family tree | | | | | | | | |!| | | | | | | | | | | |!| | | | | |}}
{{Family tree | | | | |,|-|-|-|^|-|-|-|.| | | | | | | |!| | | | | |}}
{{Family tree | | | | D01 | | | | | | D02 | | | | | | |!| | | | | |D01=Rheumatoid positive|D02=Rheumatoid negative}}
{{Family tree | | | | |!| | | | | | | |!| | | |,|-|-|-|+|-|-|-|.|}}
{{Family tree | | | | E04 | | | | | | E05 | | E01 | | E02 | | E03 | | |E04=RA<br>Lupus<br>Scleroderma|E05=AKS<br>Psoriatic arthritis<br>Reactive arthritis|E01=Gout|E02=Pseudogout|E03=Calcium hydroxapatite crystals}}
{{Family tree/end}}
==Differentiating Gout from Pseudogout==
Gout can be differentiated from pseudogout based on the following characteristics:

{| class="wikitable"
! style="background:#4479BA; color: #FFFFFF;" align="center" + |
! style="background:#4479BA; color: #FFFFFF;" align="center" + |Gout
! style="background:#4479BA; color: #FFFFFF;" align="center" + |Pseudogout
|-
| style="background:#DCDCDC; + " |'''Definition'''
|
* Supersaturation of [[Extracellular fluid|extracellular fluids]] and [[Blood plasma|plasma]] with [[uric acid]] leading to monosodium urate (MSU) crystal deposition in the [[joint]] spaces is called gout.
|
* Acute and chronic inflammatory joint disease leading to deposition of [[Calcium pyrophosphate|calcium pyrophosphate dihydrate (CPPD)]] deposition in the joints leads to [[Chondrocalcinosis|pseudogout]].
|-
| style="background:#DCDCDC; + " |'''Pathogenesis'''
|
* Increased production or decreased excretion of [[uric acid]] leads to hyperuricemia.
|
* Shedding from [[Cartilage|articular cartilage]] into joint space where they are phagocytosed by [[Neutrophil|neutrophils]] and incite an inflammatory response, leading to [[Crystal|crystal formation]].
|-
| style="background:#DCDCDC; + " |'''Clinical Features'''
|
* [[Arthritis|Acute arthritis]]: 
** [[Pain]] 
** [[Swelling]] of the joint 
** Warmth 
** [[Tenderness]]

* [[Arthritis|Chronic arthritis]]: 
** Chronic nonsymmetric [[synovitis]] 
** Periarticular [[Tophus|tophi]] formation

* [[Kidney stone|Nephrolithiasis]] 
** [[Renal colic]]
|
* Acute CPPD arthritis: 
** [[Pain]] 
** [[Swelling]], frequently involving the knee 
** Redness

* Chronic arthropathy: 
** Progressive degeneration in multiple joints

* Symmetric proliferative synovitis
|-
| style="background:#DCDCDC; + " |'''Diagnosis'''
|
* [[Aspiration|Joint aspiration]]
** [[Synovial fluid]] analysis shows both intracellular and extracellular needle-shaped negatively birefringent MSU crystals by polarizing microscopy

* [[Uric acid|Serum uric acid levels]]

* Urine [[uric acid]]

* [[Serum creatinine|Serum creatinine levels]]
|
* [[Synovial fluid]] analysis:
** Demonstration of CPPD crystals appearing as rhomboids with weak positive birefringece by polarizing microscopy
|-
| style="background:#DCDCDC; + " |'''Treatment'''
|
* [[Analgesia]]
* [[Non-steroidal anti-inflammatory drug|NSAIDs]]
* [[Glucocorticoid|Intraarticular glucocorticoids]]
* [[Glucocorticoid|Systemic glucocorticoids]]
* [[Allopurinol]], [[Febuxostat]]
* [[Probenecid]], [[Sulfinpyrazone]]
|
* [[Non-steroidal anti-inflammatory drug|NSAIDs]]
* Intraarticular injection of [[glucocorticoids]]
* [[Colchicine]]
|}