Abstract. During 1985During -1995 clinically and epidemiologically compatible with Brazilian spotted fever were identified in 17 patients in the county of Pedreira, in the state of São Paulo, Brazil. Spotted-fever group rickettsial infection was confirmed by serology and/or immunostaining of tissues in 10 of these patients. Immunostaining confirmed infection in a 37-year-old pregnant patient, although rickettsial antigens were not demonstrable in the tissues of the fetus. A serosurvey was conducted in four localities in the county to determine the prevalence of subclinical or asymptomatic infections with spotted fever group rickettsiae. Five hundred and twenty-five blood samples were tested by an indirect immunofluorescence assay for antibodies reactive with Rickettsia rickettsii. Twenty-two (4.2%) of these samples demonstrated titers Ն 1:64. The results indicate that Brazilian spotted fever is endemic within this region of Brazil.

Silicone and nonsilicone gel dressings are equally effective in the treatment of keloids and hypertrophic scars.

Transepithelial elimination of the elastotic material may be a feature of HLE. Some HLE lesions may present as keratoacanthoma, but classical features of LE aid the correct diagnosis. SCC may arise on a long-standing HLE lesion; therefore HLE requires clinical and histopathological follow up.

Histological features were useful in the diagnosis of oral cGVHD. It is suggested that CD8-T cells and macrophages play important role in the pathogenesis of the disease.

What is known and objective Polymyxins were widely used until the 1960s; however, they fell into disfavour owing to their toxicity. The subsequent growth of infections caused by multidrug-resistant Gram-negative bacteria has led to renewed use of this class of antimicrobials in clinical practice. Acquired skin hyperpigmentation (SH) following intravenous polymyxin B treatment has been previously reported, but little is known about its pathogenesis, clinical course and treatment. To improve understanding of these issues, we conducted a prospective study of adult patients receiving intravenous polymyxin B treatment. Methods Patients receiving intravenous polymyxin B treatment were followed throughout the course of treatment. Clinical, dermatoscopic, histologic and immunohistochemical skin properties of patients who presented with SH were studied. Results and discussion Skin hyperpigmentation was noted in 8% of patients (n=20/249); however, clinical, dermatoscopic, histologic and immunohistochemical examinations were performed only in three patients for whom the consent of relatives was obtained. Histologic and immunohistochemical findings showed an abundant melanocyte-pigmented dendritic network. Langerhans cells' hyperplasia and dermal IL-6 overexpression were also found, presumably for an inflammatory process due to polymyxin B use. As polymyxin B causes the release of histamine, which is known for its melanogenic effect, it is possible that skin darkening is associated with this inflammatory mediator. What is new These clinical and dermatoscopic findings contribute to a better understanding of how the pigmentary reaction manifests following intravenous polymyxin B treatment. Conclusion We concluded that hyperpigmentation due to intravenous polymyxin B treatment is associated with an inflammatory process and subsequent melanocyte activation. Although the pigmentary disorder neither influences the outcome of the therapy nor warrants discontinuation of treatment, it nevertheless considerably affects the patient's quality of life.