Hyperuricemia and Sensation of Walking on Glass Without Joint Inflammation
Elevated uric acid alone cannot cause a feeling of walking on glass in the absence of joint inflammation, as this sensation is typically associated with crystal deposition in tissues that would show inflammatory changes on examination.
Relationship Between Hyperuricemia and Foot Pain
Hyperuricemia is a well-established risk factor for gout but is not itself diagnostic of gout or a direct cause of pain symptoms without crystal deposition 1. The European League Against Rheumatism (EULAR) guidelines clearly state that "the diagnosis of gout should not be made on the presence of hyperuricemia alone" 1.
When evaluating the sensation of walking on glass without visible joint inflammation, consider:
Asymptomatic crystal deposition: Research has shown that approximately 34% of patients with asymptomatic hyperuricemia have detectable urate deposits (tophi) on ultrasound examination, particularly in tendons and soft tissues 2. These deposits can occur in the absence of classic inflammatory arthritis.
Subclinical inflammation: Of patients with asymptomatic hyperuricemia and detectable tophi, 23% show increased vascularity (inflammation) on ultrasound 2. This suggests that subclinical inflammation may be present even when not clinically apparent.
Location of deposits: Tophi are more frequently found in knees than ankles and are especially prevalent in the distal patellar tendon 2. However, deposits in foot structures could explain painful sensations.
Diagnostic Approach
For patients presenting with a sensation of walking on glass without obvious joint inflammation:
Rule out other causes: First exclude other conditions that can cause similar sensations:
- Peripheral neuropathy
- Plantar fasciitis
- Metatarsalgia
- Morton's neuroma
- Stress fractures
Laboratory testing: Measure serum uric acid levels, but recognize that:
Advanced imaging: Consider ultrasound examination of affected areas to detect:
- Subclinical tophi in tendons and soft tissues
- Increased vascularity indicating inflammation
- The "double contour" sign (urate crystal deposition on cartilage surfaces)
Definitive diagnosis: If possible, aspiration and examination of synovial fluid for monosodium urate crystals remains the gold standard for diagnosis 1.
Management Considerations
If hyperuricemia with subclinical crystal deposition is suspected:
Lifestyle modifications: Reduce intake of purine-rich foods, limit alcohol consumption (especially beer and spirits), avoid sugar-sweetened beverages, and increase fluid intake 3.
Medication review: Consider discontinuing medications that may elevate uric acid levels, such as thiazides and loop diuretics, if clinically appropriate 3.
Pharmacologic therapy: Current guidelines do not recommend urate-lowering therapy for asymptomatic hyperuricemia 3. However, if pain symptoms are attributed to subclinical crystal deposition, treatment may be considered on an individual basis.
Important Caveats
Diagnostic pitfall: Attributing foot pain solely to hyperuricemia without evidence of crystal deposition may lead to missed diagnoses of other conditions.
Monitoring: If hyperuricemia is present, regular monitoring of uric acid levels (every 3-6 months) and kidney function is recommended 3.
Special populations: Consider renal uric acid excretion assessment in patients with a family history of young-onset gout, onset of gout under age 25, or history of renal calculi 1, 3.
Comorbidities: Hyperuricemia is associated with hypertension, chronic kidney disease, and cardiovascular disease 4, 5, 6, which may require additional management considerations.