Vascular changes in cutaneous leishmaniasis.

Fifty cases of proven human cutaneous leishmaniasis were histopathologically studied. In twenty biopsies the picture was vascular alternations with or without fibrinoid necrosis and fibrin thrombi in both arteries and veins within the area of the inflammation in the lesions. Hyalinosis and intimal proliferation were also seen. On the other hand, immunoperoxidase staining of CL. lesions showed IgG and IgA within the endothelial cells, in the media and the perivascular space of the diseased vessels. It seems that the formation of immune complexes in the infected skin was responsible for the vascular changes.