CUTANEOUS PATHOLOGY IN PRIMARY ERYTHERMALGIA

Primary or idiopathic erythermalgia is characterized by recurrent, red , warm, and painful lower extremities. It arises at young age and pers ists throughout life because no treatment is available. We report the cutaneous pathology of affected skin lesions of three patients with pr imary erythermalgia. Biopsy specimens showed a mild perivascular monon uclear infiltrate, thickened blood vessel basement membranes, abundant perivascular edema, and moderate endothelial swelling. The thickened basal membrane of the blood vessels showed a laminar structure, and ab undant perivascular edema and moderate endothelial cell swelling were evident. These histopathologic findings in primary erythermalgia appea r to be nonspecific but allow diagnostic differentiation from erythrom elalgia in which fibromuscular intimal proliferation and occlusive thr ombi in the endarteriolar capillaries are apparent and from erythermal gia secondary to vasculitis. Histopathologic examination of affected s kin lesions in patients with red, congested, warm, and painful burning extremities is a valuable tool in the diagnostic process.