The American Journal of dermatopathology
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Perniosis are inflammatory cutaneous lesions, located on acral skin, which present in association with cold exposure. They can appear as an idiopathic dermatosis or with an underlying autoimmune disease. ⋯ The most frequent histopathological features observed in cases of IP were a lymphocytic infiltrate with perivascular (8 cases, 89%) and perieccrine distribution (6 cases, 66%), dermal edema (5 cases, 55%), and necrotic keratinocytes (5 cases, 55%), whereas those found in perniosis associated with an autoimmune disease were lymphocytic infiltrate with perivascular distribution (11 cases, 100%) but without perieccrine distribution (3 cases, 27%), vacuolation of the basal layer (7 cases, 63%), and necrotic keratinocytes (5 cases, 45%). The only significant difference between both groups was the perieccrine distribution of the lymphocytic infiltrate in cases of IP, which, as mentioned in previous studies, could be considered a histopathological clue to differentiate both types of perniosis.