What is Bacillary Angiomatosis?
Bacillary angiomatosis, also known as epithelioid angiomatosis, is a rare disease. It involves the unusual growth of new blood vessels in the skin or internal organs, resulting in lump-like masses. This growth is due to an infection caused by either Bartonella henselae or Bartonella quintana bacteria. The condition was initially identified mainly in HIV patients, but has also been found in people with other health conditions that weaken the immune system, as well as in people with healthy immune systems.
The unusual growths found in internal organs, known as ‘peliosis’, often occur in the liver and spleen. Bacillary angiomatosis was first identified in 1983 as an unusual skin infection associated with AIDS.
What Causes Bacillary Angiomatosis?
Bacillary angiomatosis is a disease caused by either one of two types of bacteria: Bartonella henselae and Bartonella quintana. The symptoms of the disease differ depending on which bacteria is present. Both can cause skin lesions, but B. quintana is also often associated with lesions under the skin and on the bones. On the other hand, B. henselae can cause peliosis, a condition where blood-filled sacs form in the liver and spleen.
B. henselae is a curved, rod-shaped bacterium that thrives in environments with a temperature of 37 degrees Celsius (about body temperature). It is an aerobic bacterium, meaning it needs oxygen to survive. It is known for looking like a cauliflower under the microscope, and it’s around 2 microns long. It has a circular genome, or genetic code, that is slightly bigger than its counterpart, B. quintana.
B. quintana is also a rod-shaped bacterium, but it grows more slowly. Under normal circumstances, it takes around 12 to 14 days to isolate this bacteria, but sometimes it can take up to 45 days. It’s smaller than B. henselae, measuring about 0.4 mm wide and 1.5 mm long.
Unlike some other types of bacteria, neither B. henselae nor B. quintana have flagella, which are like little tails that bacteria use to move around. Instead, they move with a twitching motion, made possible by extensions on their surface called fimbriae.
Risk Factors and Frequency for Bacillary Angiomatosis
Bacillary angiomatosis is a condition that was first seen in HIV patients, particularly those with low counts of a type of cell called CD4. This disease, which most often affects the skin but can also occur in bones and the liver, became less common among HIV patients once antiretroviral therapy became available. Still, it can occur in HIV patients who don’t take their medication as prescribed or who are diagnosed with HIV late. Many of the cases are seen in those with fewer than 100 CD4 cells. It’s been reported in all states in the US, with more cases in states with higher HIV populations like California, New York, and Florida. Only a few cases are reported in Europe compared to North America, but cases have also been noticed in Africa, Southeast Asia, the Middle East, Australia, and South America. In the United States, about 40% of cases are Caucasians, 40% are blacks, and 20% are Hispanics. Majority of the cases of bacillary angiomatosis have been found in men. It is extremely a rare condition in children, but can affect people of any age. There are two types of bacillary angiomatosis, one caused by B. henselae and the other by B. quintana, and both of these types impacts males and females equally.
Although this condition is most commonly associated with HIV, it can also occur in people who aren’t HIV positive, such as those who’ve had organ transplants, those with chronic hepatitis B, patients with leukemia, and those undergoing chemotherapy, especially when their CD4 cell counts are low. Sometimes, it can even affect people with normal immune systems, at a burn or a cat scratch site, for example, and look like a different condition called a pyogenic granuloma. Hence, it should be considered in the list of possible diagnoses regardless of a patient’s immune status.
- Bacillary angiomatosis typically occurs in people with low CD4 cells, often seen in HIV patients.
- The rate of this disease decreased with the introduction of antiretroviral therapy but can still occur if patients are not compliant with their treatment or if HIV is diagnosed late.
- This condition most often affects the skin, but it can also occur in the bones and the liver. Er, internal organ involvement can be fatal.
- It’s been noted across the United States and many other parts of the world, but there’s a higher occurrence in areas with larger HIV populations.
- Bacillary angiomatosis affects both males and females equally and can occur at any age, though it’s very rare in children.
- It can also occur in non-HIV patients, like those with organ transplants, chronic hepatitis B, leukemia, or undergoing chemotherapy.
- It can affect the immune competent patients too at the sites of burns or cat scratches.
Signs and Symptoms of Bacillary Angiomatosis
Bacillary angiomatosis is a condition that generally starts with a small bump that enlarges into a reddish or purple nodule, which may look like it has blood vessels running through it. These nodules can vary in size – they can be as small as a pinhead or as large as 10 cm in diameter. As a nodule grows, it can cause ulceration and bleeding. This condition often affects the upper extremities, and a patient may have multiple bumps and nodules since these often occur in groups. People often get this condition confused with conditions like Kaposi’s sarcoma (especially in HIV patients) and pyogenic granuloma. It is essential to remember that even though the microscopic analysis of bacillary angiomatosis is similar to that of pyogenic granuloma, they are different conditions.
Even in a healthy person, a mysterious bump or a nodule may point towards bacillary angiomatosis. In addition to affecting the skin, the condition can also cause issues in your mouth, throat, nose, genital and anal areas. If it affects your gastrointestinal mucosa or tract lining, it can even lead to bleeding. This medical condition can also have systemic effects, meaning it can affect your entire body, leading to issues like changes in mental state, heart inflammation, weight loss, and abdominal pain. Though neurological involvement is rare, there have been instances where the disease affected the brain before the skin.
Bacillary angiomatosis can sometimes be an invasive disease, caused by either B. henselae or B. quintana bacteria. These bacteria can infect various parts of the body including the heart, brain, liver, spleen, throat, lymph nodes and gastrointestinal tract. It’s important to note that there doesn’t necessarily need to be a history of exposure to cats for one to contract this disease. Symptoms related to this type of bacillary angiomatosis can include fever, swollen lymph nodes, enlarged organs, anemia and an elevated alkaline phosphatase (an enzyme found in several tissues throughout the body). In severe cases, spontaneous bleeding can occur leading to hemoperitoneum (a condition where blood collects in the space between the inner lining of the abdominal wall and the organs). Other possible symptoms include fever, chills, weight loss and loss of appetite.
In patients who are not severely immune-compromised, inflammatory nodules may occur in the internal organs without angiomatosis. This kind of presentation is believed to be somewhere between bacillary angiomatosis and cat scratch disease, caused by the B. henselae bacterium. Additionally, B. quintana infections could result in bacillary angiomatosis that affects the skin, subcutaneous tissues, and bone, but they do not cause pellet-filled (peliosis) conditions in the liver and spleen.
Testing for Bacillary Angiomatosis
When a skin lump or “nodule” is found, a biopsy might be performed to diagnose a condition called bacillary angiomatosis. It’s also essential to rule out other diseases that could affect the liver and spleen. Doctors will also further evaluate a patient based on any other symptoms and physical examination findings. Some diseases that patients can be mistakenly diagnosed with, due to similar symptoms, include cancers such as KS and PG, as well as benign hemangiomas. There might be some confusion in areas where certain diseases are common. By looking at tissue samples under a microscope, doctors can differentiate between bacillary angiomatosis and other conditions like neovascular tumors.
Tissue samples, also known as histology, are typically used to confirm a diagnosis of bacillary angiomatosis in regular medical practice. Various staining techniques, like H and E stain or Warthin-Starry, are used to help visualize different features under the microscope, like bacteria. However, these methods can’t identify the exact type of bacteria causing the illness.
Testing a patient’s blood for the presence of bacteria and the body’s response to infection can be more accurate than trying to grow the bacteria in a laboratory dish. More modern tests, like Immunofluorescence assays (IFA) and immune enzyme assays (EIA), are particularly effective. National public health authorities like the CDC have reported that these tests are 85% to 94% accurate. However, there are some drawbacks. Similar bacteria can show the same results in these tests as they cause the body to produce similar responses.
Another type of testing called PCR can identify and differentiate between different species of Bartonella bacteria. This test can be done on whole blood, serum or plasma samples. On the other hand, methods that try to grow these bacteria, known as culture methods, are less reliable. In people with heart inflammation caused by bacteria (endocarditis), one study found that only 28% of vial cultures and 5% of agar plate cultures were positive. As a result, these culture methods are rarely used in medical practice.
Treatment Options for Bacillary Angiomatosis
The preferred medications for treating this condition are erythromycin or doxycycline, which are types of antibiotics known as macrolides. If a patient has difficulty tolerating these drugs, alternatives such as azithromycin or clarithromycin may be used instead.
Minor skin infections can usually be treated with these medications for 12 weeks. The effectiveness of the treatment can be determined by monitoring the size and number of any skin nodules, with noticeable improvement generally seen after 3 to 4 weeks.
For the treatment to be effective, it may sometimes be necessary to extend the duration of antibiotic therapy. In severe cases where the infection has spread, the treatment period may need to be longer.
It is recommended to consult with an infectious disease specialist for guidance on treatment duration and strategy. For patients with weakened immune systems, treatment should continue until the number of a certain type of white blood cell, called CD4 T-helper cells, is back to normal. For patients with HIV, alongside taking antiretroviral medication, the treatment should continue until the CD4 count is above 200 cells/microliter for over six months.
In addition to antibiotics, other treatments may be used as an extra measure to combat the skin manifestations of the infection. These can include techniques like cryotherapy (using extreme cold to destroy diseased tissue), electrodesiccation with curettage (which is a type of surgery), or removing the lesions surgically. These measures should, however, only be performed after antibiotic treatment to avoid triggering widespread infection in the body.
It should be noted that the responsiveness of these bacteria to treatment in lab tests might not exactly match the response seen in patients. Certain drugs like tetracyclines, macrolides, and rifampin may hinder the growth of the bacteria in lab tests.
In terms of prevention, it’s not usually necessary to get rid of a cat that may be carrying the bacteria because the period of potential transmission is relatively short. Also, it doesn’t make a difference if the cat is declawed or not as this does not affect transmission rates to humans. The most effective prevention measure is regularly controlling fleas, as fleas are the common means of transmission.
What else can Bacillary Angiomatosis be?
In simple terms, the skin changes caused by certain medical conditions might look quite similar. For instance, conditions like Kaposi sarcoma, pyogenic granuloma, and epithelioid hemangioma can present similar skin lesions. In areas where certain diseases are common, these lesions might also be mistaken for a condition known as verruga peruana, which is caused by a bacteria called ‘B. bacilliformis.’
Sometimes, if there are multiple swollen lymph nodes along the arm, it could be mistaken for a condition called sporotrichosis. So, it’s important for doctors to carefully analyze the symptoms and conduct proper tests to make the correct diagnosis.
What to expect with Bacillary Angiomatosis
Bacillary angiomatosis, a type of infection, can improve quickly with early use of antibiotics. However, in patients with weakened immune systems, the condition often returns, especially after stopping the treatment. It’s important to treat this infection properly, as it can be deadly if left untreated.
Possible Complications When Diagnosed with Bacillary Angiomatosis
Bacillary angiomatosis is a condition that can impact various organs such as the heart, brain, liver, spleen, voice box (larynx), lymph nodes, and the digestive system. Some of the complications that can arise from this condition include:
- Bleeding in the digestive system
- Encephalopathy, a general term for brain disease, damage, or malfunction
- Endocarditis, an inflammation of the inner layer of the heart
- Blockage of the voice box
- Disfigurement caused by extensive skin lesions
Preventing Bacillary Angiomatosis
Bacillary angiomatosis, a bacterial infection, can be quickly cured with the right use of antibiotics if diagnosed and treated early. However, if it is not treated properly, it can lead to severe outcomes, even death. The best way to prevent it is through effective measures to control fleas.
