mucormycosis
Introduction
Introduction to mucor Mucor is a systemic fungal infection caused by many fungi such as Rhizopus, Mucor, Pythium or Mortierella, which has a rapid onset, rapid development and high mortality. Pathogens can enter the human body through the respiratory tract, digestive tract, skin or skin mucosa, which is good for invading arterial blood vessels, causing thrombosis, tissue ischemia, infarction and necrosis. In recent years, with the increase of immunodeficiency population, the incidence rate is on the rise. basic knowledge The proportion of sickness: 0.002% - 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: Diabetes Paronychia
Cause
Cause of mucor
(1) Causes of the disease
It is mainly a deep mycosis caused by Mucor, Mucor, Trichoderma, Rhizopus or Rhizopus, which invades the blood vessel wall and blood vessel cavity, causing inflammation and thrombosis.
(two) pathogenesis
Mucor is a common contaminating bacteria, which is a pathogenic bacteria. The bacteria are parasitic on soil, fertilizers and fruits. Spores can be caused by breathing into the lungs and sinuses of humans, and can also cause gastrointestinal infections. .
The lung type and brain type of the disease are often secondary to severe diabetes (such as diabetic acidosis), malignant lymphoma, alcoholism, liver disease or severe anemia, and can also be caused by long-term use of corticosteroids.
Prevention
Mucor prevention
Primary prevention
(1) Separate susceptible patients with filtered air or laminar air to prevent cross-infection in hospitals.
(2) Control of diabetes, lymphoma and leukemia patients, strict control of immunosuppressive agents, cytotoxic drugs, anticancer agents, etc., have a certain preventive effect.
(3) Strengthen food management and prevent fungal pollution.
2. Secondary prevention
Because the disease is very urgent and serious, early diagnosis is extremely important. Because mucormycosis is often difficult to detect in secretions, and it is difficult to identify, early diagnosis mainly depends on clinical evidence: that is, the disease is urgent, the condition is fierce, and the first part of the disease is the nasal brain. Following the chest, abdomen, pelvis, stomach and skin, pathogenic factors include acidosis of diabetes, leukemia and lymphoma of lung infection, malnutrition of intestinal infection, such as protein deficiency in children, combined with clinical manifestations, experiments Room (including fungal culture) and pathological examination (secretion, extracts, scraping, etc.) may achieve rapid diagnosis. Once diagnosed, amphotericin B should be used immediately, and 1.2 mg/kg should be administered every other day. Immediate control, surgical debridement in the nasal cavity, there are also advocated combination therapy, in addition to amphotericin B, plus 5-Fc, itraconazole or fluconazole.
3. Three levels of prevention
Timely use of amphotericin B can reduce the mortality rate of this disease from 80% to 90% to about 50%, control diabetes, nasal necrotic tissue for surgical debridement, can improve the prognosis of this disease.
Complication
Mucor complication Complications, diabetes, paronychia
Diabetes, gastrointestinal necrosis, perforation, skin type may also be associated with paronychia.
Symptom
Symphylactic symptoms Common symptoms Dyspnea coma Chest pain Pupil fixed diarrhea Meningitis Sleepless intestinal bleeding Nodule Peritonitis
Lung type
Symptoms similar to upper respiratory tract infection, bronchial pneumonia or lobar pneumonia, upper respiratory tract ulcers, fever, cough, hemoptysis, dyspnea, chest pain, chest X-ray and routine bacteriological examination without diagnostic significance, conventional culture positive rate Very low, definitive diagnosis relies on the discovery of characteristic hyphae in the sputum and lung biopsy tissue, which can be done by fiberoptic bronchoscopy, percutaneous lung biopsy, such as patients with diabetes often die within 2 to 10 days .
Brain type
Mainly manifested as facial pain, headache, fever, lethargy, triad syndrome: uncontrollable diabetes; eye symptoms such as swelling of the ankle, pain, drooping eyelids, pupillary fixation and loss of vision; meningitis, semi-conscious or coma State, Yohai proposed six factors affecting the prognosis of the disease, namely delayed diagnosis and treatment, hemiparesis or hemiplegia, bilateral sinus involvement, leukemia, renal insufficiency and treatment with desferrioxamine, the mortality rate of this type is as high as 80% to 90%.
3. gastrointestinal type
This type is considered to be caused by ingestion of food contaminated with fungal spores. The original is in infants and young children, children are more common, malnutrition, premature delivery, navel inflammation, use of contaminated masks, nasogastric tube feeding, etc. are possible diseases. Factors, stomach, duodenal ulcer and mucormycosis infection, has gradually increased in recent years, may have symptoms of diarrhea, gastrointestinal bleeding and peritonitis, can cause gastrointestinal necrosis and perforation in severe cases.
4. Skin type
It is the lightest type of mucormycosis. It is common in children and adolescents. It often has a history of skin damage. Mucor spores implant cause clinical infection. Skin mucor may be divided into two types, namely superficial And gangrenous type, superficial type mainly manifests as subcutaneous nodules, most nodules can be fused into plaques, the edges are clear, the nodules are generally not red, hard, no depression, no adhesion to subcutaneous tissue, lack of consciousness Symptoms, histopathological manifestations of dermal plaque granulomatous inflammation, which has wide and undivided transparent hyphae, rare invasive blood vessels, gangrenous skin mucormycosis is a rapid progress of infection, nodules and subcutaneous tissue adhesion The color is deepened, it can be broken, and most suppurative ulcers are formed. The pain is obvious, and it can be accompanied by paronychia. It can also spread to subcutaneous fat and muscle tissue or organs, or spread through blood.
5. Dispersion type
All of the above 4 mucormycosis may develop into disseminated infections, which can be widely spread to the brain, lungs, gastrointestinal tract, heart, kidney and other organs. Patients with long-term use of antibiotics and immunosuppressants in clinical practice, if sustained Fever, accompanied by respiratory, digestive tract and nerve symptoms should consider the possibility of disseminated mucormycosis, the disease is mostly disseminated by blood, the most common part of dissemination is the lungs.
Examine
Mucor examination
Direct microscopic examination and culture of fungi: specimens from upper turbinate scrapings, sinus aspirate, alveolar lavage fluid, sputum and biopsy specimens, etc., multiple examinations are the same type of mucor, with diagnostic value, direct microscopic examination of typical hyphae Branches, at right angles, cysts directly grow from hyphae.
Mucor disease can invade all organs of the body, mostly with arterial embolism, tissue ischemia, infarction and ischemia as the main lesions. Biopsy in the invaded blood vessel wall or infarct tissue can be seen by the silver staining method. Separated, branched into a right angle of hyphae, histopathological manifestations of dermal plaque granulomatous inflammation, which has wide, undivided transparent hyphae, rare invasive blood vessels.
Diagnosis
Diagnosis and identification of mucor
Deterministic diagnosis relies on the identification of characteristic hyphae in the sputum and lung biopsies, which can be accomplished by fiberoptic bronchoscopy and percutaneous lung biopsy.
