[A new case of nevus oligemicus].

Nevus oligemicus is a rare lesion characterized by selective vasoconstriction of the deep dermal vascular plexus compared with the superficial one. It has been suggested that it may be caused by increased sympathetic tone in the deep dermal vascular plexus or an abnormality of hormone receptors, which is why it is considered a functional nevus. Clinically, it presents as an asymptomatic, fixed, livid erythematous macule with a striking decrease in local temperature compared with surrounding healthy skin. We report the case of a 59-year-old man with a 2-year history of three large areas of persistent and asymptomatic livid erythema on trunk and flanks. These areas blanched under light pressure. Measurement of the surface temperature of the patch revealed a decrease of up to 2.5 degrees C with respect to surrounding skin. Histology showed superficial dermal capillary dilatation without other significant findings. The fixed nature of the lesions, consistent histopathology, and the finding of localized hypothermia allowed the diagnosis of nevus oligemicus. The diagnosis is mainly clinical. Our case is the eleventh case of nevus oligemicus reported in the literature.