The expanding spectrum of eschar-associated rickettsioses in the United States.

Background: Until recently, Rickettsia rickettsii was the only substantiated cause of tick-borne spotted fever group (SFG) rickettsiosis in humans in the United States. Rickettsia parkeri, originally thought to be nonpathogenic in humans, was recently proved to be another cause of tick-borne SFG rickettsiosis.

Observations: We report 3 cases of SFG rickettsiosis and discuss the epidemiology, clinical presentation, histopathologic features, and laboratory findings that support confirmed or probable diagnoses of R parkeri infection and describe the expanding list of eschar-associated SFG rickettsioses recognized in US patients.

Transitional cell neoplasm of the nasolacrimal duct associated with human papillomavirus type 11.

Background: Tumors of the lacrimal sac are rare but noteworthy because of their significant potential to become malignant or life-threatening if treatment is delayed. Dermatologists may be the first to encounter such neoplasms.

Observations: We report a case of a 53-year-old Caucasian woman who presented with a seven-year history of an asymptomatic, subcutaneous nodule near her right medial canthus.

Tropical dermatology: Tropical diseases caused by protozoa.

Unlabelled: Protozoan infections are very common among tropical countries and have an important impact on public health. Leishmaniasis is the most widely disseminated protozoan infection in the world, while the trypanosomiases are widespread in both Africa and South America. Amebiasis, a less common protozoal infection, is a cause of significant morbidity in some regions.

Vaccines under study: non-HIV vaccines.

The development of effective vaccines has been an amazing public health achievement and has resulted in countless lives being saved. Dermatologic therapy has recently been greatly advanced by the licensure of an effective human papillomavirus vaccine and herpes zoster vaccine. Despite these successes, many infectious diseases do not currently have a preventive vaccine.

Vaccine immunology.

This article provides a review of immunology to enhance understanding of vaccine efficacy and use, and elaborates on the immune response to vaccination. The use of vaccines to prevent infectious diseases represents a tremendous accomplishment of biomedical science, especially considering the complex interplay of the immune system with innumerable pathogens. Vaccines have allowed for total eradication of one disease and have significantly reduced the incidence of other diseases.

Safety and efficacy of vaccines.

For the past two centuries, vaccines have provided a safe and effective means of preventing a number of infectious diseases. Although the safety of some vaccines has been questioned in recent years, the currently available vaccines are more than a millionfold safer than the diseases they are designed to prevent. Vaccines, however, should always be used in conjunction with other public health interventions.

Famciclovir treatment options for patients with frequent outbreaks of recurrent genital herpes: the RELIEF trial.

Background: Recurrent genital HSV outbreaks are common among those suffering from the disease. Antiviral medications taken as suppressive therapy can reduce the frequency of these recurrences and reduce viral shedding occurring in between recurrences.

Objectives: To investigate the efficacy and safety of oral famciclovir as episodic (125 mg twice daily for 5 days) and suppressive (250 mg twice daily) treatment of recurrent genital herpes (RGH).

Etanercept: an overview of its role in the treatment of psoriasis.

Background: Psoriasis is a chronic and disabling disease affecting patients' quality of life.

Objectives: Over the past decade, there has been significant growth in the knowledge of the proinflammatory pathways involved in psoriasis, including the role of increased levels of TNF. This knowledge has led to the increased use of biologic therapy, with such drugs as etanercept, a soluble TNF receptor fusion protein, aimed at inhibiting the actions of TNF.