Mucormycosis was formerly also known as cycomycosis. It is the third most common fungal infection after candidiasis and aspergillosis. The disease occurs predominantly in people with an immunodeficiency.
What is mucormycosis?
Mucormycosis is a fungal infection with a fulminant course. The causative agents are fungi from the zygomycete family. Normally, zygomycetes belong to the saprophytes. Saprophytes feed exclusively on dead organic matter. In the case of immunodeficiency, however, the actually harmless saprophytes can become parasites and cause severe damage to the body. The rhinocerebral form of the disease is particularly feared. In this case, the fungi enter the brain via the paranasal sinuses and cause the most severe damage.
Causes
The causative agents of mucormycosis are filamentous fungi that grow filamentously. Because they are usually harmless but can cause severe damage under certain circumstances, they are classified as facultative pathogenic fungi. The most common pathogens of mucormycosis are fungi of the genera Mucor, Rhizomucor, Rhizopus, Lichtheimia and Cunninghamella. The fungi have a worldwide (ubiquitous) distribution and are found primarily in soil. Normally, humans are immune to these fungi. However, with a weakened immune system, they can spread in the respiratory tract, gastrointestinal tract or on the skin. In the process, the pathogens penetrate tissue and blood vessels quite quickly. In particular, patients with diabetic ketoacidosis, patients after stem cell transplantation or organ transplantation, as well as patients receiving corticosteroid therapy or persons with severe burns are predisposed. Patients with T-cell defects or advanced HIV infection are also particularly susceptible to mucormycosis.
Symptoms, complaints, and signs
Five forms can be distinguished in mucormycosis. All are life-threatening:
- The most common form is rhinoorbitocerebral mucormycosis. It is found mainly in children with diabetes mellitus or in leukemia patients. Characteristic symptoms of this form of progression are redness, pain and swelling in the area of the face and orbit. The infection begins in the sinuses and causes sinusitis there. The nasal secretions are bloody. In addition, black tissue lesions of the nasal mucosa appear.
The filamentous extensions of the fungi break through the skin and grow into the tissues and bones, so that facial soft tissues, the orbit, the meninges and the frontal brain can also be affected. Damage to arteries and veins also leads to increased thrombosis and infarction. Changes in consciousness, central paralysis, and visual disturbances indicate involvement of the central nervous system.
- In pulmonary mucormycosis, the lungs are primarily affected by the fungi. Here, too, thromboses and infarctions occur. These are often accompanied by fever, shortness of breath, and chest pain. Cancer patients with acute leukemia are particularly affected. The infection may arise from rhinoorbitocerebral mucormycosis. However, it usually develops directly in the lungs after inhalation of the fungal spores.
- In children with acute leukemia, disseminated mucormycosis is most commonly found. It begins in the lungs and then spreads through the bloodstream to the other organs and the central nervous system. Disseminated mucormycosis is almost always fatal.
- Primary gastrointestinal mucormycosis is diagnosed less frequently. It is characterized by ulcers in the gastrointestinal tract and occurs predominantly in immature newborns. The ulcers are at risk of perforation. By penetration of the pathogens into the blood vessels, infarctions can also occur here.
- Mucormycosis of the skin is seen in patients with severe burns or in leukemia patients. Black necrosis of the skin is typical of this form of progression.
Diagnosis and course of the disease
Clinical and radiographic findings are similar to those of other fungal infections. Therefore, diagnosis can be made only with the help of cultural, microscopic, or histopathologic evidence of the pathogen. Diagnostic material can be obtained by biopsies or surgical procedures. Possible procedures for obtaining material include skin or soft tissue biopsies, endoscopies of the nose and sinuses, bronchoscopy with lavage, or CT-guided biopsies.In rhinocerebral mucormycosis, diagnostic imaging also reveals mucosal thickening in the area of the paranasal sinuses. Pulmonary mucormycosis shows nonspecific and extensive lesions of the lungs on radiography. Patchy infiltration, melting, or pleural effusions may be visible. If the orbit is affected, a pathologic mass appears there. In addition to pathogen detection, detailed imaging by computed tomography and magnetic resonance imaging is always required. Only in this way can the full extent of the infection be detected.
Complications
Various symptoms may occur in the patient due to mucormycosis. As a rule, this disease must be treated by a doctor in any case, because it can be life-threatening and in the worst case leads to the death of the patient. Those affected suffer primarily from severe swelling in the face and also in the eye socket. There are nosebleeds and also changes in consciousness. Ordinary thinking and acting is only possible with difficulty for the affected person and most patients suffer from severe visual disturbances. Without treatment, fever and shortness of breath then occur, which can lead to loss of consciousness. Chest pain may also occur. Ulcers form in the intestines or stomach, which can also lead to the death of the affected person. The quality of life decreases significantly due to mucormycosis and everyday life becomes much more difficult for the patient. The treatment of mucormycosis takes place with the help of medication or chemotherapy. It cannot be predicted whether this will result in a positive course of the disease. In many cases, life expectancy is significantly reduced by mucormycosis.
When should one go to the doctor?
Mucormycosis should be clarified by a doctor at an early stage. At the latest when typical symptoms such as skin changes on the palate and infections in the area of the nose and throat are noticed, a medical professional must be consulted. Otherwise, further extension of the necrosis may occur. Signs such as seizures, aphasia, or hemiplegia indicate advanced disease that must be evaluated immediately. People with chronic infectious diseases, recurrent infections or a generally weakened immune system are particularly susceptible to the development of mucormycosis and should seek medical attention urgently if their health deteriorates noticeably. The same applies to elderly and sick people, pregnant women and children. In addition to the family doctor, ENT physicians and specialists for infectious diseases are recommended. Children should always be presented to the pediatrician in charge first. If health problems arise again after treatment, the responsible physician must be informed due to the risk of recurrence. Constant medical monitoring is also indicated during treatment for mucormycosis.
Treatment and therapy
Treatment of mucormycosis is multimodal. The cornerstone is always antifungal chemotherapy. In addition, attempts are made to eliminate the underlying immunologic or metabolic defect. This forms the breeding ground for the fungi. If the underlying disease is not eliminated, the fungi will spread again after chemotherapy. Treatment is supplemented with antifungal drugs such as amphotericin B. The duration of therapy depends on the extent of mucormycosis. Depending on age, pathogen and underlying disease, mortality ranges from 50 to 70 percent. Only with consistent therapy do patients have any chance of survival. The prognosis is worsened by disseminated infections, cancer as the underlying disease, and diseases associated with a deficiency of granulocytes. Once the central nervous system is reached, the disease is almost always fatal.
Outlook and prognosis
In general, an unfavorable outcome can be assumed for mucormycosis. According to statistical surveys, 50 to 70 percent of those with the disease die. Thereby, the risk for premature death is distributed differently. It increases with further basic illnesses and a high age. If symptoms have spread to the central nervous system, death is usually inevitable. In general, persons with a weakened immune system and a metabolic disease are considered comparatively susceptible to mucormycosis. In them, the disease is comparatively severe and usually leads to life-threatening complications.The therapeutic approaches available to date are mostly inadequate. It is precisely this fact that causes the high mortality rate. In any case, only consistent therapy can contribute to recovery. Starting treatment at an early stage promises better prospects. In practice, it often proves problematic that an exact diagnosis is not possible. In many cases, therefore, treatment is started on a mere suspicion. Only the demise then allows a determination of the disease. In the recent past, science has developed molecular biological methods for a diagnosis. Improvements can be expected from this.
Prevention
To date, no effective and specific prophylaxis for mucormycosis exists. Mucormycosis in children or adolescents with diabetes mellitus can be prevented by optimal adjustment of blood glucose. Persistently elevated blood glucose levels compromise the immune system, favoring fungal infections.
Follow-up
In the case of mucormycosis, very few measures and options for direct aftercare are available to the affected person in most cases. For this reason, the affected person should see a doctor as early as possible to prevent the recurrence of symptoms and complications. As a rule, mucormycosis cannot be cured on its own. Most of those affected are dependent on help and care from their own family. In many cases, this can also prevent depression and other psychological complaints or upsets. Furthermore, it is not uncommon to need to take various medications to completely limit the symptoms of this disease. The affected person should always pay attention to a regular intake and also to a correct dosage in order to alleviate the symptoms permanently and above all correctly. As a rule, the affected person should also protect himself particularly well against infections. In this regard, vaccinations should also be carried out to prevent the development of various diseases. In some cases, mucormycosis also reduces the life expectancy of the patient. However, the further course is strongly dependent on the time of diagnosis, so that a general prediction can usually not be made in this case.
What you can do yourself
Mucormycosis must always be examined and treated by a physician. Medical therapy can be supported by a change in lifestyle and various self-help measures. During radiation or chemotherapy, the affected person must take it easy. A special diet reduces the typical gastrointestinal complaints and promotes the regression of the metastases. At the same time, any allergies must be clarified and any medications taken must be checked and adjusted if necessary. Patients who regularly resort to headache tablets or other medications should inform the physician about this. Optimally adjusted medication reduces the risk of complications and can also promote recovery. If thrombosis, visual disturbances, paralysis or other problems have already developed as a result of the mucormycosis, these must be treated separately. The doctor will refer the patient to a specialist for this. The most important self-help measure is to keep a record of complaints and symptoms, because this allows the stage of mucormycosis to be determined precisely and the treatment to be selected optimally. In addition, serious complications can be detected and treated at an early stage before a life-threatening condition develops. Because fungal infection is a protracted disease, close medical monitoring is indicated even beyond the initial treatment.
