Bacillary Angiomatosis
Definition
A life-threatening but curable infection that causes an eruption of purple lesions on or under the skin that resemble Kaposi's sarcoma. The infection, which occurs almost exclusively in patients with AIDS, can be a complication of cat-scratch disease.
Description
Bacillary angiomatosis is a re-emerging bacterial infection that is identical or closely related to one which commonly afflicted thousands of soldiers during World War I. Today, the disease, caused by two versions of the same bacteria, is linked to homeless AIDS patients and to those afflicted with cat-scratch disease.
The infection is rarely seen today in patients who don't have HIV. According to the U.S. Centers for Disease Control and Prevention (CDC), an HIV patient diagnosed with bacillary angiomatosis is considered to have progressed to full-blown AIDS.
Causes and symptoms
Scientists have recently isolated two varieties of the Bartonella bacteria as the cause of bacillary angiomatosis: Bartonella (formerly Rochalimaeaquintana) and B. henselae (cause of cat-scratch disease).
B. quintana infection is known popularly as trench fever, and is the infection associated with body lice that sickened European troops during World War I. Lice carry the bacteria, and can transmit the infection to humans. The incidence of trench fever was believed to have faded away with the end of World War I. It was not diagnosed in the United States until 1992, when 10 cases were reported among homeless Seattle men.
The related bacteria B. henselae was first identified several years ago as the cause of cat-scratch fever. It also can lead to bacillary angiomatosis in AIDS patients. Bacillary angiomatosis caused by this bacteria is transmitted to AIDS patients from cat fleas.
These two different types of bacteria both cause bacillary angiomatosis, a disease which is characterized by wildly proliferating blood vessels that form tumor-like masses in the skin and organs. The nodules that appear in bacillary angiomatosis are firm and don't turn white when pressed. The lesions can occur anywhere on the body, in numbers ranging from one to 100. They are rarely found on palms of the hands, soles of the feet, or in the mouth. As the number of lesions increase, the patient may develop a high fever, sweats, chills, poor appetite, vomiting, and weight loss. If untreated, infection may be fatal.
In addition to the basic disease process, the two different types of bacteria cause some slightly different symptoms. Patients infected with B. henselae also experience blood-filled cysts within the liver and abnormal liver function, whereas B. quintana patients may have tumor growths in the bone.
