Bacillary angiomatosis is a chronic infectious disease caused by bartonella bacteria. The disease is attributed to opportunistic invasions, most often found among HIV-infected people in the AIDS stage. The main manifestations are skin changes, fever, lymphadenopathy, and in some cases, lesions of internal organs. Diagnostics is based on microscopy, PCR examination of histological preparations and detection of antibodies to the pathogen. Treatment is carried out with the help of etiotropic antibacterial and symptomatic agents, sometimes surgical aid is required.
Bacillary angiomatosis (epithelioid angiomatosis) is attributed to pseudoneoplastic bacteriosis. Bartonella were named after the Peruvian scientist Barton, who discovered them in 1909, but for the first time an American doctor Stoler made a description of the clinic of this pathology in a patient with HIV infection in 1983. The prevalence of the disease is widespread, there is no clear seasonality. Nosology has no age-specific features, while up to 90% of patients are male. Risk groups are people with decompensation of the immune system due to the presence of AIDS, long-term use of glucocorticosteroids, chemotherapy and radiation therapy.
The causative agent of the disease is the Bartonella microorganism. Most human bartonella infections are caused by three bacteria: B. henselae, B. quintana and B. bacilliformis. The occurrence of bacillary angiomatosis is associated with the invasion of the first two types. Bartonella has the ability to enhance endothelial proliferation, vascular capillary growth. The main source and reservoir of infection are cats, the transmission of pathogens between which occurs transmissively with the help of cat fleas. People become infected by contact with bites, scratching by sick cats, while infection can also occur from person to person through the bites of lice.
There is no primary affect at the site of bartonella invasion. Penetrating through the skin and mucous membranes, the pathogen penetrates into red blood cells, affecting up to 40-90% of circulating red blood cells, and capillary endotheliocytes. Multiplying on the cell surface, bacteria trigger the development of extensive inflammation with the accumulation of neutrophils, eosinophils and the rapid appearance of necrosis. The mechanism of neoangiogenesis is complex: it is based on the ability of proteins of the outer membrane of bartonella to induce a decrease in the activity of interferon-1, stimulate the production of angiopoietin-2 and the reproduction of epithelial cells.
Bartonella with blood and lymph flow spread throughout the body, mainly settling in the lymph nodes, spleen, bone marrow, skin, liver. The introduction into erythrocytes allows bacteria to avoid an immune response, since they accumulate in the vacuoles of the host cell, are resistant to heat shock proteins, free radicals and produce the protein deformin, which allows them to rebuild the cytoskeleton of erythrocytes. Due to this, a long-term persistence of bacteria in the body and asymptomatic carrier is formed.
The classification of bacillary angiomatosis is based on the degree of invasion of the bacterium into the human body (cutaneous and visceral, or extra-cutaneous, form). Mainly there is a cutaneous manifestation of bacteriosis, which can include subcutaneous localization. Extracutaneous variants , depending on the affected organ , can be divided into the following forms:
- Infection of the musculoskeletal system. The most characteristic lesion of long tubular bones, as well as vertebrae, ribs, calcaneal and cranial bones. Bone marrow in this type of bartonellosis is involved less often.
- Infection of the respiratory system. Angiomatous polypoid lesions are found throughout the respiratory tract, can cause the formation of acute and chronic respiratory failure.
- Gastrointestinal infection. The gastric and intestinal mucosa is mainly involved, isolated cases of oral cavity lesions are described. With extra-cavity localization in the mesentarial lymph nodes, compression of the common bile duct often occurs.
- CNS infection. Manifests itself with epileptic seizures, symptoms of lesions located near the cranial nerves. Cases of aseptic meningitis are described for this type of disease.
The incubation period of the disease is decades, since the pathogen is a component of the normal human flora and is activated only with a deep depletion of immunity. The onset of the disease is gradual, with moderate fever (37.5-38 ° C), weakness, decreased performance, increased regional lymph nodes. Then there are skin rashes of any localization (except palms, soles), randomly located, their number can reach several hundred, less often thousands. Also, there are no elements on the mucous membranes of the nose and mouth.
The rash at first looks like small dense painless bumps of reddish-purple color, which eventually grow, rising above the plane. With a subcutaneous location of the focus, the integuments are hyperemic, the nodes reach several centimeters, and may be accompanied by purulent discharge. Bone damage is characterized by severe pain, difficulty walking, manual manipulation, and cephalgia when the skull is involved.
The presence of bacillary angiomatosis of the brain can cause epilepsy, hemorrhagic strokes. The appearance of angiomatous formations in the stomach cavity, intestines leads to persistent nausea, a change in the nature of the stool, complicated by massive bleeding. Extra-cavity localization is manifested by vomiting, heartburn, jaundice, severe abdominal pain. The growth of angiomatous nodes in the respiratory tract can manifest itself as a clinic of shortness of breath, dry cough and hemoptysis, complicated by acute respiratory failure due to obstruction of the laryngeal lumen.
The most common complications are bleeding of various localization and intensity, chronic anemia, massive bacteremia, which with bacillary angiomatosis can lead to the occurrence of infectious endocarditis, meningoencephalitis. Often, especially among patients with AIDS, there are relapses of the disease. Isolated observations of spontaneous hemoperitoneum are described. With multiple bone lesions, deformities of the limbs, contractures and disability of patients may occur.
To establish the diagnosis of bacillary angiomatosis, an examination of an infectious disease specialist is required, according to the indications of other specialists. The following laboratory and instrumental methods serve as diagnostic tools necessary for the verification of the disease:
- Objective inspection. During physical examination, papules, reddish-purple vascular nodules, moderately painful when pressed, are found on the patient’s skin. The surface of the formations is easily injured and bleeds, can be eroded, hyperpigmented to a black hue, have scaly peeling. Regional lymph nodes without signs of purulent process, enlarged to 1-8 cm. With visceral angiomatosis, hepatosplenomegaly, symptoms of dysfunction of the affected organ may be observed.
- Laboratory tests. In general clinical blood analysis – thrombocytopenia, acceleration of ESR and anemia. Among the biochemical indicators, an increase in the activity of lactate dehydrogenase, AST, ALT, total and indirect bilirubin, CRP is revealed. Changes in urine analysis with severe hemolysis: urobilinuria, proteinuria, hemoglobinuria. In the coprogram, when the intestine is affected, a large number of erythrocytes, sterkobilin is detected, a test for hidden blood becomes positive.
- Identification of infectious agents. Histological assessment of the biopsy of the affected skin area makes it possible to differentiate various vascular formations with bacillary angiomatosis, to detect pathogens. The use of the PCR method makes it possible to identify bartonella without resorting to complex and expensive culturological techniques. ELISA is considered positive with more than a fourfold increase in the titer of antibodies, while there is a cross-reactivity between the species of bartonella, cocciella and chlamydia.
- Instrumental techniques. Chest radiography allows you to identify nodules in the lungs. Bronchoscopy, EFGDS, ECHO-CS are indicated for patients to receive biopsies and differential diagnosis. An X-ray of bones with their lesion reveals areas of delimited osteolysis with periostitis. Ultrasound of the abdominal cavity, soft tissues, lymph nodes, bones allows you to determine the presence of a visceral form of the disease. In case of brain damage, EEG, MRI with contrast is recommended.
Differential diagnosis is carried out with Kaposi’s sarcoma, the difference of which is the malignancy of cells and the lack of reaction to antibacterial therapy, hemangiomas of other etiology, sporotrichosis, which is characterized by the formation of nodes with fistula openings mainly on the distal extremities, and other deep mycoses. Osteoarticular, pulmonary tuberculosis is confirmed by microscopic, cultural, X-ray methods. The presence of endocarditis is primarily associated with beta-hemolytic streptococcus group A and the formation of specific vegetations on the valves detected by echocardioscopy.
Inpatient treatment is indicated in the presence of lesions of internal organs, as well as in the moderate and severe course of the disease. Bed rest is recommended up to stable figures of normal body temperature for 2-4 days. There are no fundamental dietary recommendations, however, given the duration of antibacterial treatment, some side effects of drugs, low immune status of patients, it is necessary to adhere to a healthy diet with adequate water load, excluding alcohol, nicotine, marinades, excess seasonings.
The drugs of choice for etiotropic treatment are macrolides (erythromycin, azithromycin), tetracyclines (doxycycline) and rifampicin. In combination with HIV infection, taking antibiotics is recommended to a steady CD4+ lymphocyte level of more than 200 cl / ml for six months. Surgical therapeutic methods are indicated only in combination with antibacterial ones, since when the angiomatous node is excised, there is a risk of dissemination of the pathogen. Such procedures include cryodestruction, electrodissection and removal of formations with a scalpel.
Prognosis and prevention
The prognosis is favorable, in the case of timely treatment, recovery occurs within 4-12 weeks, sometimes spontaneous resolution of foci is observed. With a deep deficiency of immunity, the probability of death is higher. Currently, no specific prophylaxis (vaccines) have been developed. Non-specific prevention consists in limiting contact with wild and domestic animals, compliance with personal hygiene standards, regular medical examination in the presence of HIV infection. An important factor is the rational antibiotic therapy of sick cats, the fight against cat fleas, and the improvement of sanitary and hygienic living conditions of the population.