Pulmonary mucormycosis

Introduction to pulmonary mucor Pulmonary mucormycosis is a pulmonary infection caused by Mucormycosis, often with underlying diseases such as diabetes, and high mortality. Pulmonary mucormycosis is high in mortality due to its morbidity. Amphotericin B and surgical debridement have a curative effect on the treatment of concurrent diseases, correcting electrolyte imbalance, correcting acidosis, and the mortality rate begins to decrease. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: respiratory infection Complications: Diabetes Myocardial infarction

Cause of pulmonary mucor

Infection (30%):

The fungus that can cause pulmonary mucormym belongs to the genus Zygomycete, Mucor, Mucor, Mucor, and other families in the genus Mucor, such as the genus Mortier, the genus Caused by mold, bottle mold, etc., among which Rhizopus, Mucor, and Absidia are the most common type 3 fungi causing pulmonary mucormycosis; and 3 species are Rhizopus The most common causes, especially Rhizopus arrhizus and Rhizopus oryzae.

Route of infection (30%):

In normal humans, human plasma inhibits the growth of Rhizopus. Neutrophils have the effect of killing mold hyphae. When the body's defense mechanism is destroyed or weakened, pathogens can invade the body. The respiratory tract is the main infection route. Skin and intestinal infections, diabetic acidosis, blood diseases, lymphoma, myeloproliferative disorders, long-term use of corticosteroids, chemotherapy and radiotherapy are the causes of mucormycosis, and severe leukopenia and diabetes are important causes.

Pathology (25%):

The pathogen grows and propagates from the nasal mucosa and submucosal tissue, and quickly destroys the tissue causing sinusitis, inflammation around the eyeball, and can also directly invade the brain and meninges, or the lungs. Spores that invade the lungs can pass through the bronchial wall and enter the lung tissue and blood vessels. Rapid growth in tissues, small arterial embolization and acute suppurative inflammation of the lung parenchyma, massive leukocyte infiltration, tissue necrosis, hyphal invasion of blood vessels, causing embolism, not only accelerate the spread of infection, but also cause tissue infarction, pathological changes It is characterized by vascular embolism and tissue necrosis.

Pulmonary mucor disease prevention

1. The pathogen of this disease is a conditional pathogen. For susceptible patients, systemic diseases should be treated promptly to improve the body's resistance. If this disease occurs, in addition to timely treatment, cross-infection of other bacteria should be avoided.

2. Accurately grasp the rational application of immunosuppressive drugs.

Pulmonary mildew complications Complications, diabetes, myocardial infarction

Concurrent diabetes, acidosis, pulmonary infarction, myocardial infarction and so on.

Pulmonary mildew symptoms Common symptoms Alfalfa has black eschar, abdominal pain, ptosis, chest pain, difficulty breathing, coma, sleepiness

Nasal mucormycosis

Acute, rapid and dangerous progress, manifested as facial pain, headache, lethargy, severe cases can cause blindness, physical examination showed brown in the nose, bloody slightly sticky secretions, black eschar in the infected side, when II, IV When VI is involved in cranial nerves, it can also cause dilated pupils, fixation, convex eyes or ptosis. During the process of disease progression, fungi easily invade large blood vessels, causing infarction and necrosis in the brain, accompanied by brain softening, patients often From drowsiness to coma, death within 7 to 10 days, the mortality rate of this type is 80% to 90%.

2. Pulmonary mildew

Mucor is highly susceptible to invasion of the elastic intima of large and small blood vessels due to fungal spores (3-6 m) inhaled in the air or fungal spores in the paranasal sinus infected by inhalation, or due to the spread of blood from distant lesions. Causes thrombosis, hemorrhage and infarction, clinical manifestations of non-specific pneumonia, chest pain, dyspnea, hemoptysis, chest X-ray and routine bacteriological examination without diagnostic significance, the incidence of this disease in patients with leukemia and lymphoma is high In cancer patients, primary pulmonary mucormycosis can also occur in diabetic patients with a poor prognosis, ranging from 3 days in short to 30 days in the long term.

3. Disseminated mucormycosis

Mucor can be widely spread to the kidney, gastrointestinal, heart, brain, which is most commonly affected by the lungs, and is more difficult to diagnose. Cardiac involvement can be found in thick-walled fungi in the coronary arteries to form embolism, pathogens often from the skin The traumatic blood flow to other organs.

4. Gastrointestinal mucor

Gastrointestinal mucormycosis is thought to be caused by ingestion of food contaminated with fungal spores. Primary is associated with malnutrition, especially in children, and severe gastrointestinal dysfunction is also a predisposing factor, such as Jiaxi. (Kwashierkor) disease, amebic colitis, typhoid, etc., clinical manifestations depending on the location and extent of involvement, such as non-specific abdominal pain, atypical gastric ulcer, diarrhea, hematemesis and black feces.

5. Skin mucor

The lightest type of mucormycosis, either primary or secondary to other lesions (eg, blood source inoculation), lesions are progressively enlarged infarctular nodular erythema, up to several centimeters, one The pale circle around the red ring edge can have necrosis, eschar formation, central ulcer and erosion, histopathology sees local necrosis of skin and adipose tissue, and skin mucormycosis often occurs in burns or diabetic patients, so these patients The cause of death is often associated with the merger of other infections such as mucor.

Pulmonary mucor

Direct microscopic examination

Specimens from the upper turbinate scrapings, sinus aspirate, sputum and biopsy specimens, direct microscopic examination with 20% potassium hydroxide wet film, visible typical thick-walled refraction hyphae, diameter 6 ~ 15m, also The expanded cells and curved hyphae can be seen, and the cysts are directly grown by the hyphae, and the hyphae can be branched and have a right angle.

2. Cultivation

The clinical specimens were inoculated into the maltose medium without cycloheximide, the potato medium and the common Sabour culture medium, and cultured at 37 ° C or 25 ° C, the growth was faster, the surface of the colony was cotton-like, white, and the gradient was Gray-brown or other colors, mucormycosis is dangerous, and mucormycosis often pollutes the environment and the environment, so direct microscopic examination is often more meaningful than culture.

3, X-ray chest

  Shows non-specific pneumonia and pulmonary infarction.

Diagnosis and identification of pulmonary mucor

diagnosis

Diagnosis is mainly based on predisposing factors, clinical manifestations, bronchial or focal secretions, bronchoalveolar lavage fluid culture, lung tissue biopsy to find mucor that can be diagnosed, tissue sections found in the vessel wall with short, thick, branched and undivided Mucor hyphae The most diagnostic significance exists.

Differential diagnosis

The disease needs to be differentiated from bacterial, viral, Candida pneumoniae or Aspergillus pulmonary infection, lung abscess, and hollow lung tumor. Sometimes clinical and X-ray images are difficult to identify, and pathogen identification must be repeated.

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