Unilateral Hand Pain After Distal Radius Fracture: CRPS or Something Else?
Ms. A is a 54-year-old right-handed woman evaluated 7 months after a distal radius fracture treated with casting. She reports constant burning pain (8/10) in the right hand and wrist, with swelling, color changes, and intolerance of light touch; she cannot wear a sleeve. She has type 2 diabetes (A1c 7.8%) with mild bilateral foot numbness, and a workers' compensation claim is pending. Examination shows nonpitting edema of the dorsum of the hand, temperature asymmetry (right hand 2.1°C cooler), allodynia to light brush, and hyperalgesia, but no weakness or atrophy. Radiographs show healed fracture; MRI is normal. She is tearful and says, 'Everyone thinks I'm faking.'
1. Apply the Budapest criteria to this presentation. Which findings are most and least useful, and what confounders must you exclude?
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The Budapest criteria require: (1) continuing pain disproportionate to any inciting event; (2) at least one symptom in three of four categories-sensory, vasomotor, sudomotor/edema, motor/trophic; (3) at least one sign at the time of assessment in two or more categories; and (4) no other diagnosis better explains the findings. Here she reports sensory (allodynia/hyperalgesia), vasomotor (color/temperature change), and sudomotor/edema symptoms; examination confirms allodynia, edema, and a 2.1°C temperature asymmetry. That satisfies symptom and sign requirements. The most discriminating signs are temperature asymmetry, sudomotor changes, and edema; pain intensity and color change alone are nonspecific. The least useful are subjective burning and swelling without observed signs. Confounders: diabetic neuropathy can cause bilateral burning but not unilateral edema and temperature asymmetry; disuse can cause swelling but not allodynia; infection, DVT, nonunion, and median/ulnar neuropathy must be excluded. Because CRPS is a clinical diagnosis of exclusion, normal MRI and healed fracture do not refute it. Document observed signs, not just reported symptoms.
2. What additional assessment would you perform before committing to CRPS as the primary diagnosis, and how would you use diagnostic testing?
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Before finalizing CRPS, I would map the pain and sensory findings beyond the fracture territory; examine for median or ulnar nerve entrapment (Tinel sign, Phalen maneuver, two-point discrimination) and consider EMG/NCS if the distribution is unclear; exclude infection, DVT, nonunion, and mimics such as diabetic radiculoplexus neuropathy; assess motor and trophic changes (hair, nails, sweating); screen for depression, anxiety, and catastrophizing because these affect function but do not invalidate CRPS; and obtain functional measures such as grip strength, range of motion, and limb volume. Diagnostic sympathetic blocks are not required and have limited specificity; three-phase bone scan is not routinely needed. If findings are atypical or progressive, I would reconsider. The goal is to avoid both underdiagnosis (dismissing genuine CRPS) and overdiagnosis (labeling disuse or neuropathy as CRPS).
3. How do you manage the compensation context and the patient's distress without compromising diagnostic accuracy or rapport?
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I would validate her distress and explicitly separate clinical care from the compensation claim. I would avoid attributing symptoms to secondary gain, which is rarely the explanation and damages trust. I would document objective findings, functional limitations, and response to treatment, and use standardized measures over time. I would coordinate with physical therapy and pain psychology, set function-based goals, and communicate factually with the insurer when authorized. I would explain that CRPS is a recognized condition and that the claim does not change the diagnostic approach. If inconsistencies arise, I would explore them nonjudgmentally rather than accusing her of malingering. This preserves rapport while maintaining diagnostic rigor.