Immune complexes in the reactive inflammatory vascular dermatoses.

Immune complexes are formed by the interaction of antigen and antibody. When these complexes are deposited in tissue, they activate complement that is chemotactic to neutrophils. Neutrophil release of lysozymal enzymes results in destruction of tissue. In the skin this destruction manifests itself clinically as vasculitic lesions. Occasionally other clinical lesions, such as urticaria, erythema multiforme, and so forth, may be a manifestation of immune complex disease.