Reflex sympathetic dystrophy with prominent involvement of the nail apparatus.

After closed hand trauma, a 17-year-old boy had acute inflammatory changes that resembled bacterial whitlows of the third and fourth right fingers. Clearing of the inflammatory changes was followed by the development of cyanosis, hyperhidrosis, and roentgenographic evidence of patchy osteoporosis in the involved extremity. Findings of a biopsy specimen revealed that the inflammatory lesions in the proximal nail folds were caused by proliferation of capillary vessels embedded in edematous loose connective tissue. This is the first report of cutaneous histopathologic findings in the first stage of reflex sympathetic dystrophy, although similar features have been described in synovial and bone biopsy specimens of patients with reflex sympathetic dystrophy.