Clinical, histopathologic & immunologic features of cutaneous lesions in acute meningococcaemia.

ABSTRACT

Fifty children with culture proven acute meningococcaemia were studied during the winter outbreak of the disease in 1986-87. Purpuric lesions were seen in 60 per cent, erythematous papules in 32 per cent, faint pink macules in 28 per cent, conjunctival petechiae in 10 per cent and herpes labialis in 20 per cent. Histopathology of skin lesions showed that the primary damage was to the dermal vessels, the extent of damage depending on the type of skin involvement. Diplococci in Gram's stained sections were seen frequently in purpuric as compared to the other skin lesions. They were located in degenerating neutrophils, endothelial cells, fibrin clots or freely in the vascular lumen. Electron microscopic study showed vascular changes accompanied by a perivascular phagocytic response. Both light and electronmicroscopy indicated the involvement of the coagulative mechanism in the pathogenesis of meningococcaemia. However, clinical parameters of clotting were often within normal limits. In the case of a child (who died eventually), a low platelet count and prolonged coagulation indices were observed. Sera from some of the children were tested for the presence of antibodies against meningococci by indirect immunofluorescence. Antibodies were detected in the sera and they may have a role in regulating the severity and course of the illness. The significance of immunoglobulin deposits in the skin lesions is not clear.