[Pigmentation and venous stasis].

Local pigmentations can occur in the course of venous diseases and are said to be secondary to venous stasis and due to blood pigment. Most often, the pigment is haemosiderin and more rarely melenin pigments. Haemosiderin is a result of dermal biligenesis of extravasated red blood cells, the erythrodiapedesis being due to alterations in the vessel wall. Melanin pigments remain a mystery. Meaanoid may stimulate dermal melanocytes more than the true melanocytes of neural origin which have migrated to the epidermis. Above all, the problem is dominated by stasis and its microvascular and tissue consequences. The pigmentation is part of the "microangiopathy of stasis", as are the pigmentations occurring after therapeutic sclerosis.