ABSTRACT
Cutaneous biopsies of five eschars and two rash lesions from five patients from New York City with documented rickettsialpox were examined by immunohistochemical methods with a monoclonal antibody directed against spotted fever group rickettsial lipopolysaccharide for the presence and cellular location of Rickettsia akari Rickettsiae were identified in all of the five patients, with good concordance of results for the same biopsy tissues with previously reported results by the direct immunofluorescence method. In contrast with immunofluorescence, which did not reveal the location of the organisms, immunohistochemical examination demonstrated R. akari to be in perivascular cells, morphologically resembling macrophages. Evaluation with double staining for rickettsiae and either CD68 or Factor VIII-related antigen revealed that the predominant infected cell type was CD68-positive macrophages, and only a rare rickettsia was detected in vascular endothelium, the major target cell for other rickettsioses. These results provide a diagnostic method for rickettsialpox and other spotted fever group rickettsioses and indicate that the elucidation of the pathogenesis of rickettsialpox must take into account that its target cell differs from that of Rocky Mountain spotted fever, boutonneuse fever, louse-borne typhus fever, and murine typhus.
Subject(s)
Macrophages/microbiology , Rickettsiaceae Infections/diagnosis , Rickettsiaceae Infections/immunology , Animals , Antibodies, Monoclonal , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Biopsy , Humans , Immunohistochemistry , Lipopolysaccharides/metabolism , Macrophages/metabolism , Mice , Rickettsiaceae/isolation & purification , Rickettsiaceae Infections/metabolism , Rickettsiaceae Infections/microbiology , Skin Diseases/immunology , Skin Diseases/metabolism , Skin Diseases/microbiologyABSTRACT
Vasopressin (Pitressin, 8-arginine vasopressin) is a potent vasoconstrictor of splanchnic arterioles. When administered by continuous intravenous infusion, it reduces portal blood flow and pressure and is used in the management of bleeding esophageal varices. We describe a purpuric and necrotic cutaneous reaction to vasopressin that occurred at locations distant from intravenous catheter sites, and we review previous reports of similar reactions.
Subject(s)
Drug Eruptions/diagnosis , Esophageal and Gastric Varices/drug therapy , Gastrointestinal Hemorrhage/drug therapy , Vasopressins/adverse effects , Dose-Response Relationship, Drug , Drug Eruptions/pathology , Humans , Infusions, Intravenous , Male , Middle Aged , Purpura/chemically induced , Purpura/pathology , Skin/pathology , Vasopressins/therapeutic useABSTRACT
BACKGROUND: Rickettsialpox is caused by Rickettsia akari, which is transmitted from rodents to humans by bloodsucking mites. The initial skin lesion forms an eschar and is followed by the development of fever, malaise, myalgia, and 5 to 40 maculopapules and papulovesicles. The disease, which responds to tetracycline, can be mistaken for chickenpox. The diagnosis has been based on an increase in serum antibody titers against R. akari over a period of three to eight weeks. We discuss a more rapid technique that uses direct immunofluorescence to identify R. akari in paraffin-embedded tissue, and we describe the histopathological findings of lesional skin. METHODS: We studied 13 patients (age, 11 months to 58 years) who were seen at Lincoln Hospital in New York City from 1980 to 1989 and were suspected of having rickettsialpox. In nine patients serum samples were obtained during the acute and convalescent phases of the illness for indirect fluorescent-antibody testing. Punch-biopsy specimens of skin lesions were examined by microscopy and by direct fluorescent-antibody testing with an anti-R. rickettsii globulin conjugated with fluorescein isothiocyanate. RESULTS: The diagnosis was confirmed in all 13 patients by indirect or direct fluorescent-antibody techniques. Direct fluorescent-antibody testing of eschars from seven patients was positive in five patients, but negative in two patients who had serologically confirmed rickettsialpox. In contrast, direct fluorescent-antibody testing of papulovesicles from nine patients was positive in only one patient. Histopathological analysis of the eschars revealed extensive necrosis and inflammation. In biopsy specimens of papulovesicles, dermal edema, subepidermal vesicles, and vascular changes were present. CONCLUSIONS: The combination of direct fluorescent-antibody testing of an eschar from the presumed site of inoculation and histopathological examination of papulovesicles for distinctive features represents an improved method of diagnosing rickettsialpox.
Subject(s)
Rickettsia Infections/diagnosis , Skin Diseases, Bacterial/diagnosis , Adult , Antibodies, Bacterial/analysis , Boutonneuse Fever/diagnosis , Child , Female , Fluorescent Antibody Technique , Hospitals, Urban , Humans , Infant , Male , Middle Aged , Necrosis , New York City , Rickettsia/immunology , Rickettsia/isolation & purification , Rickettsia Infections/pathology , Rickettsia rickettsii/isolation & purification , Rocky Mountain Spotted Fever/diagnosis , Skin/microbiology , Skin/pathology , Skin Diseases, Bacterial/microbiology , Skin Diseases, Bacterial/pathologyABSTRACT
Seven cases of a distinctive vascular proliferation in patients with acquired immunodeficiency syndrome are discussed and compared with other reported cases. All cases share clinical and pathologic manifestations that can be recognized early. Warthin-Starry-positive bacilli within some of the lesions and their response to erythromycin may indicate that the proliferation is associated with an infectious agent, possibly the bacillus that causes cat-scratch disease.
