Could Posterior Heel Pain, Swelling, and Heat Be Gout?
Yes, gout can present with swelling, heat, and pain in the back of the heel, particularly affecting the Achilles tendon or retrocalcaneal bursa, especially in patients with hyperuricemia or a history of kidney stones. 1, 2, 3
Clinical Features Supporting Gout in the Heel
Gout commonly affects periarticular structures including bursae and tendons, with the Achilles tendon and olecranon bursae being recognized sites for acute gouty flares. 2, 3
- Acute gout characteristically reaches maximum pain intensity within 6-12 hours of onset, with severe pain, swelling, and tenderness accompanied by overlying erythema 1
- The rapid development of symptoms (worst within <24 hours) is highly suggestive of crystal inflammation, though not specific for gout 1
- Male gender, associated cardiovascular diseases, and hyperuricemia are additional supportive clinical features 1
Risk Factors That Strengthen the Diagnosis
A history of hyperuricemia or kidney stones significantly increases the likelihood of gout in this clinical context. 1
- Patients with urolithiasis benefit from urate-lowering therapy, as both allopurinol and febuxostat lower 24-hour urinary uric acid excretion 1
- Hyperuricemia (defined as >mean+2SD) has a likelihood ratio of 9.74 for gout diagnosis 1
- Chronic kidney disease, obesity, diuretic use, and alcohol consumption are additional risk factors that should be assessed 1, 2
Diagnostic Approach
Synovial fluid aspiration with crystal identification remains the gold standard, but when aspiration is not feasible in periarticular structures like the Achilles tendon, imaging becomes critical. 1
When Joint/Bursal Aspiration Is Feasible:
- Demonstration of monosodium urate (MSU) crystals (needle-shaped, negatively birefringent under polarized microscopy) permits definitive diagnosis with sensitivity 84% and specificity approaching 100% 1
- Aspiration should be performed if septic arthritis cannot be clinically excluded 1
When Aspiration Is Not Feasible:
- Ultrasound should be the first-line imaging modality, looking for the "double contour sign" (sensitivity 74%, specificity 88%) or tophi appearing as hyperechoic masses 1, 4
- Dual-energy CT (DECT) has 85-100% sensitivity and 83-92% specificity for detecting MSU crystal deposition, particularly useful when ultrasound is inconclusive 1, 4
- Plain radiographs have limited value for diagnosing acute gout but can identify chronic changes and rule out alternative diagnoses 1
Critical Diagnostic Pitfalls
Do not rely on serum uric acid levels alone—hyperuricemia does not confirm gout, and normal levels during an acute attack do not exclude it. 1, 2
- Serum uric acid levels tend to decrease during acute attacks, making them unreliable for diagnosis in the acute setting 2
- Up to 80% of patients with hyperuricemia never develop gout 4
- The diagnosis should not be made on hyperuricemia alone 1
Clinical Decision Algorithm
For a patient with posterior heel pain, swelling, and heat:
Assess clinical features: Rapid onset (<24 hours to maximum intensity), severe pain, erythema, male gender, cardiovascular comorbidities 1
Evaluate risk factors: Hyperuricemia history, kidney stones, chronic kidney disease, diuretic use, alcohol consumption, obesity 1, 2
If aspiration is feasible: Perform bursal aspiration for MSU crystal identification 1
If aspiration is not feasible: Order ultrasound of the Achilles tendon and retrocalcaneal bursa looking for double contour sign or tophi 1, 4
If ultrasound is negative but clinical suspicion remains high: Consider DECT, particularly if disease duration >2 years 4
Screen for associated comorbidities: Assess for obesity, renal impairment, hypertension, ischemic heart disease, diabetes, and dyslipidemia 1
In patients with a history of kidney stones and hyperuricemia presenting with acute posterior heel inflammation, gout should be strongly considered and investigated appropriately, as these patients may benefit from urate-lowering therapy even after a first attack. 1