Immunofluorescence study of skin rash in patients with dengue hemorrhagic fever.

Fifty-three skin biopsy specimens obtained from the cutaneous rashes of patients who had dengue hemorrhagic fever (DHF) were studied by immunofluorescence technique. Six specimens showed deposits of IgM, beta 1 C-globulin, dengue antigen, and fibrinogen during the first week of fever. Some but not all of these components (IgM, beta 1 C, dengue antigen) were demonstrated in 29 specimens. Twenty-three of them yielded negative results. Granular deposits of IgM and beta 1 C appeared in the blood vessel walls of dermal papillae. Dengue antigen was seen in mononuclear cells that were closely infiltrated around the blood vessel wall in dermal papillae. Fibrinogen was located within or about the blood vessels. The findings suggest that the cutaneous rashes occurring in DHF are caused by an immunopathologic process.