ISCHAEMIC NECROSIS DUE TO INFLAMMATORY VASCULAR OCCLUSION PLUS LEPROSY REACTION
When the clinical data are correlated with the histological changes, the three first stages, early, disseminated, and well-developed, correspond to the phase in which patients have diffuse infiltration of entire skin The fourth and fifth stages of ischaemic necrosis correspond to Lucio's phenomenon or erythema necroticans.
The fourth stage of ischaemic necrosis due to non-inflammatory vascular occlusion is characterised histologically by the presence of necrotic cutaneous lesions due to vascular occlusion by endothelial proliferation or thrombosis, and clinically it coincides with the appearance of discrete purple-coloured painful spots, which lead to ulceration of the skin without systemic symptoms.
The fifth stage of ischaemic necrosis appears as an acute reactional state that may supervene in such patients and aggravates the existing vascular damage.
Causes of digital ischaemic necrosis
are most commonly due to vasculitis, either autoimmune or drug-induced.4
Most vesicovaginal fistulae (VVF) are caused by ischaemic necrosis
of bladder wall due to foetal head impaction during prolonged obstructed labour.
Zeek and Assali (1950) (9) defined placental infarction as a zone of ischaemic necrosis
of a group of villi due to complete interference with their blood supply in the deciduas, thrombosis of a spiral arteriole or a retroplacental haemorrhage.
He was a known case of Buerger's disease and had history of repeated amputations due to ischaemic necrosis
in lower and upper extremities.
Microscopy showed fallopian tube with ulceration of mucosa, large areas of hemorrhage, congested blood vessels and ischaemic necrosis
suggestive of hematosalpinx with torsion.
Despite the controversy surrounding the direct role of chemo toxic agents in the pathophysiology of NE, ischaemic necrosis
is believed to be the triggering factor, followed by bacterial invasion in the background of severe neutropenia.2,8,10,11,19,20