Meyerson phenomenon within a nevus flammeus. The different eczematous reactions within port-wine stains.

Only few reports about eczematous reactions overlying nevi flammei exist. All of them were observed in children. The description of an eczematous reaction within a congenital nevus flammeus on the left lower leg of a male adult gives reason to discuss this rare phenomenon. Eczema or inflammatory changes within a port-wine stain may mostly be a collision dermatosis with an atopic dermatitis, especially when they arise in children and are localized to the neck and face. When they are observed within a grossly visible vascular malformation, as for example in the Klippel-Trenaunay syndrome, they may have a pathogenesis similar to stasis dermatitis. In rare cases, an eczematous reaction within a nevus flammeus may be the result of genetic mosaicism and is interpreted as a variant of the so-called Meyerson phenomenon.