[Histopathology of cutaneous aphtha in Behçet's syndrome].

The authors studied cutaneous biopsies of papulo-pustular lesions in Behçet's syndrome. In biopsies taken early, superficial oedema of the dermis appeared to be the first histological sign, subsequently resulting in a true sub-epidermal bulla, containing neutrophil polynuclear and eosinophil leucocytes. At this stage no major vascular involvement was seen. In later specimens, by contrast, marked vascular changes were seen with the appearances of allergic angiitis. At this stage, there is frank epidermal necrosis with resultant ulceration.