Treatment of reflex sympathetic dystrophy with topical capsaicin. Case report. A 31-year-old woman with intractable reflex sympathetic dystrophy experienced nearly complete, though temporary, resolution of pain following 3 weeks of topical capsaicin. We propose that capsaicin may be a useful treatment for reflex sympathetic dystrophy, either by depleting substance P from primary afferent neurons that mediate allodynia, or by modulating sympathetic efferent activity. 