What is Mucormycosis?
Mucormycosis is a type of infection caused by fungi from the zygomycete family. These fungi are generally harmless and often found in the environment, and they usually won’t cause an infection unless the person’s immune system is compromised or weak.
If a person has certain underlying health conditions, they may be more susceptible to this type of fungal infection. In healthy individuals with strong immune systems, these fungi don’t typically cause problems. However, in individuals with weakened immune systems, these fungi can lead to a severe and challenging infection to treat.
The infection can take several forms, including affecting the lungs (pulmonary), stomach and intestines (gastrointestinal), skin (cutaneous), brain (encephalic), and the areas around the eyes and nose (rhinocerebral). One key thing to note is that rhinocerebral mucormycosis is different from allergic fungal sinusitis, which is a non-invasive overgrowth of fungi in the nose and sinus area and this usually affects individuals with healthy immune systems.
Mucormycosis can cause tissue death due to an invasion of blood vessels and lead to eventual clot formation, typically progressing rapidly. The key to tackling this infection is to detect it early on, and treat it aggressively via surgical removal of the infected tissue, combined with strong doses of antifungal medication given through an IV, or intravenous, line directly into the bloodstream.
What Causes Mucormycosis?
Mucormycosis is a type of infection caused by a specific type of fungus called Zygomycetes from a fungal order named Mucorales.
Certain species are often found in people with this infection. These include Apophysomyces (A. variabilis), Cunninghamella (C. bertholletiae), Lichtheimia [Absidia] (L. corymbifera L. raosa), Mucor (M. circinelloides), Rhizopus (R. arrhizus (oryzae) R. microsporus), Rhizomucor (R. pusillus), and Saksenaea (S. vasiformis). These types of fungi are usually found in the environment and are not harmful to healthy people.
However, these fungi can be dangerous to people with weak immune systems. This can include organ transplant recipients, people with HIV, people taking certain medications for conditions like rheumatism, people with leukemia or other forms of cancer. For these people, the fungi can lead to a fast-moving, damaging infection.
Similarly, it’s also risky for people with uncontrolled diabetes, especially those with a history of a serious condition called diabetic ketoacidosis.
Risk Factors and Frequency for Mucormycosis
Mucorales are a type of fungus that can survive in hot temperatures, and they’re commonly found in soil and decaying matter. They’re generally not harmful because they have a low ability to cause disease. Among those with weak immune systems, though, they can cause an infection—especially a type of Mucorale called Rhizopus. People with weak immune systems may also get infections from various types of Aspergillus fungi. Cases of mucormycosis, a disease caused by Mucorales, have been going up because more and more people have weaker immune systems. This is due to longer lifespans in people with cancer or those who’ve had organ transplants, as well as increased use of medications that can weaken the immune system to treat autoimmune diseases.
The main way people get infected by Mucorales is by breathing in spores in the air, which can then settle in the sinuses or lungs. In less common cases, people may also get infected by ingesting Mucorales or by getting them on their skin.
- There are a few conditions and situations that can put someone at higher risk of getting mucormycosis:
- Having diabetes or poor nutrition
- Having a type of cancer such as lymphomas or leukemias
- Having kidney failure or having a transplant
- Being on medications that weaken the immune system
- Having cirrhosis (a liver disease) or AIDS
- Having burn injuries
- People with diabetes who are experiencing ketoacidosis or patients on dialysis who are being treated with deferoxamine (a medication to reduce iron) are also more likely to get mucormycosis.
The most common form of the disease caused by Mucorales is called rhinocerebral mucormycosis. Even with a combination of medicine and surgery to treat it, the outcomes are usually poor unless a patient’s immune system gets stronger.
Signs and Symptoms of Mucormycosis
Mucormycosis is a type of infection that can affect various parts of the body. This includes the lungs, central nervous system, sinuses, digestive system, and skin. The symptoms of mucormycosis can vary greatly and usually progress rapidly, depending on where the fungus has entered the body and any underlying health conditions the person may have.
If the spores of the fungus are inhaled into the sinuses, this can lead to a form of mucormycosis known as ‘rhinocerebral.’ Symptoms may start out as simple nasal congestion or discharge but can become more severe, with symptoms like facial numbness, blurry vision, severe headache, and fever. Painless sores with discharge may also appear in the nose and usually worsen rapidly.
Mucormycosis can also impact the lungs, causing bilateral pneumonia which progresses quickly. This form of the disease is more common in people with blood diseases and can cause symptoms like fever, coughing up blood, difficulty breathing, and coughing. If the infection spreads, it might lead to other complications like cavitary lesions that can mimic tuberculosis.
The disease can also affect the skin either through direct contact or spreading from a different location. This can lead to cellulitis that can turn into a necrotic lesion, abscesses, skin swelling, and necrosis. This is often seen in patients with burns and traumatic skin wounds.
Mucormycosis can also invade the gastrointestinal system if contaminated food or medicine is ingrafted. Symptoms can include nausea, vomiting, ulcers, blood clots in the digestive system, and severe symptoms such as perforation and hemorrhages in the gastrointestinal tract.
In its most severe form, mucormycosis can spread from any primary sites of infection resulting in a wide range of non-specific symptoms. A distant skin lesion is a tell-tale sign of this advanced stage of the disease, which generally indicates a poor prognosis.
Testing for Mucormycosis
Blood tests might not always give a clear diagnosis, but they can reveal certain conditions that might increase your risk. For instance, neutropenia, a low number of white blood cells, is considered a risk factor.
Imaging tests can be very helpful to determine how far the disease has spread. Recommended imaging tests might be focusing on the brain, sinuses, lungs, and abdomen if mucormycosis (a rare, serious fungal infection) is suspected. These tests are crucial when doctors think there might be a problem in these areas.
If your doctors suspect rhinocerebral mucormycosis, a specific form of mucormycosis that affects the nasal cavity and the brain, they’ll use a procedure called an endoscopic evaluation. This procedure uses a thin tube with a light and camera attached to look inside the sinuses and take small tissue samples (biopsies) for examination. During this procedure, a biopsy of the middle turbinate (part of your nose structure) can be taken because it’s most likely to show if mucormycosis is present. In addition, a type of scan called a computed tomography (CT) scan can help doctors check the nearby structures, like the eyes and brain, for signs of mucormycosis.
In case you are immunocompromised and have symptoms like those of a lung infection (such as cough, fever, and shortness of breath), your doctor may order a CT scan of your chest. Mucormycosis in the lungs can resemble a simple lung infection or pneumonia, making the diagnosis tricky. A sample of fluid from your lungs may also be taken for testing.
If gastrointestinal mucormycosis is suspected (indicated by symptoms like abdominal pain or gastrointestinal bleeding), a CT scan can help examine the condition of your colon. If problematic colon conditions are found through the scan, your doctor will perform an endoscopy with a biopsy to confirm the diagnosis. The doctor will check the biopsy for characteristic features of mucormycosis.
Treatment Options for Mucormycosis
Mucormycosis, a serious type of fungal infection, is generally managed through a combination of early diagnosis, treatment of underlying conditions and risk factors, surgery to remove infected tissue, and prompt use of antifungal medications – usually amphotericin B.
Proper management includes the quick control of high blood sugar and acid levels in the body, and stopping or reducing the use of medications that weaken the immune system, if possible. Amphotericin B, an antifungal medication, is often the first choice of treatment for this disease.
As part of the treatment plan, surgery may be required urgently to get rid of the infected tissue and prevent the further spread of the infection. This could involve significant procedures such as facial surgeries, removing part of the lung or colon, depending on where the infection is located. These procedures are quite aggressive and can have substantial side effects. If a patient’s immune system cannot be sufficiently boosted, the outcomes can unfortunately be quite poor, even with aggressive treatments and dramatic surgical interventions.
Posaconazole or isavuconazole are alternative antifungal medications that can be used if the primary treatment isn’t effective. However, guidelines do not advise using both amphotericin and posaconazole together.
Additionally, hyperbaric oxygen therapy can be an additional treatment method. This involves inhaling pure oxygen in a pressurized room or tube. The high pressure of the oxygen improves the ability of white blood cells, a key part of the immune system, to kill the fungus and also helps wounds to heal.
What else can Mucormycosis be?
When it comes to diagnosing mucormycosis when it affects the nose and brain, doctors need to rule out other possible illnesses like orbital cellulitis and cavernous sinus thrombosis.
For someone having symptoms of lung mucormycosis, doctors need to also consider other conditions such as:
- Aspergillosis
- Nocardiosis
- Granulomatosis with polyangiitis (also known as Wegener granulomatosis)
What to expect with Mucormycosis
The outlook for patients depends largely on how quickly treatment begins and the overall health of the patient’s immune system. Depending on where the infection is, the chance of survival can range from 25% to 87%.
A number of factors can make the situation worse, such as if the infection has spread throughout the body, if there is kidney damage, or if the disease affects the brain and spinal cord. An inadequate response to treatment can also lead to a worse outlook.
The most crucial factor in a patient’s prognosis is their immune system’s ability to respond effectively. If their immune system is not functioning properly, the outlook is generally quite poor. However, if the immune system’s functioning can be improved, even if only temporarily, the patient’s outlook is likely to improve.
Possible Complications When Diagnosed with Mucormycosis
Mucormycosis complications can be either disease-related or treatment-related. Disease-related complications encompass issues such as blood clots in the brain, widespread infection, destruction around the eye area, mouth sores, bone infection, and even death.
Complications that are due to treatment can include kidney toxicity, lower levels of potassium in the blood, and extended hospital stays, particularly when the medication deoxycholate amphotericin B is used.
Disease Complications:
- Blood clots in the brain
- Widespread infection
- Damage around the eyes
- Mouth sores
- Bone infection
- Potential death
Treatment Complications:
- Kidney toxicity
- Lowered potassium blood levels
- Extended hospital stays