Ultrasonography for diagnosing atypical gout. Two case reports

Area of Science:

• Rheumatology
• Medical Imaging
• Crystal Arthropathies

Background:

• Gout diagnosis typically relies on identifying monosodium urate crystals in synovial fluid or tophi.
• Atypical presentations and challenges with joint aspiration can lead to misdiagnosis, such as with psoriatic arthritis.
• Accurate diagnosis is crucial for effective gout management and preventing complications.

Observation:

• Two cases of chronic gouty arthritis were initially misdiagnosed as psoriatic arthritis.
• Ultrasonography identified specific joint and bone patterns suggestive of gout.
• These patterns included the "double-contour appearance" of cartilage and "snowstorm appearance" of the synovial membrane.

Findings:

• Ultrasonography demonstrated unique findings highly indicative of gout.
• The double-contour sign and snowstorm appearance were key ultrasonographic indicators.
• Ultrasound guidance facilitated aspiration of joint fluid containing monosodium urate crystals.

Implications:

• Ultrasonography offers a valuable, non-invasive tool for diagnosing gout, especially in difficult cases.
• Improved diagnostic accuracy through ultrasonography can lead to timely and appropriate treatment of gout.
• This imaging modality may enhance the management of crystal-induced arthritis, reducing misdiagnosis rates.