[The localized form of reflex sympathetic dystrophy-a case report.].

Introduction: The reflex sympathetic dystrophy (RSD) syndrome usually shows a distally generalized distribution pattern of symptoms. Here we report a case with a distally localized form of RSD.

Patient And Methods: In a 53-year-old woman, following a local lesion in the nail bed of the left thumb, a neuroma developed at the side of the lesion during the next half year. She was finally operated upon. Following that intervention, a complex and painful clinical syndrome occurred that for the most part affected only the thumb. A clinical neurological examination was carried out, including distal suprasystolic compression of the affected extremity after bandaging it (the so-called ischemia test). For diagnostic and therapeutic reasons, afterwards a conventional blockade of the ipsilateral stellate ganglion was applied.

Results: The clinical investigation showed a triad of autonomic (swelling, side difference of skin temperature, hyperhydrosis), motor (reduced movement ability, tremor) and sensory disturbances (spontaneous pain, allodynia), which nearly exclusively affected the entire left thumb. The spontaneous pain showed an orthostatic component (the pain being diminished or exaggerated when the extremity was elevated or lowered, respectively) and was suppressed by the ischemia test. Following the sympathetic block, all symptoms disappeared within one day (follow-up period: 5 months).

Conclusion: In contrast to the common clinical picture of RSD, with a distally generalized distribution of symptoms, the present case showed a so-called localized form of RSD, its triad affecting only the thumb with the lesion. Typically, the pain showed an orthostatic component and was suppressed by the ischemia test. The sympathetic block was immediately successful, proving the occurrence of this form of RSD for the first time. In similar clinical cases, this form of RSD should be considered as a differential diagnosis.