Actinomycosis

Introduction to actinomycosis Actinomycosis is mainly a chronic suppurative inflammation caused by actinomycesisraeli. According to modern biological classification, actinomycetes are not fungi and belong to an anaerobic bacterium. Because it causes lesions similar to mycosis, and according to past habits, actinomycosis is often described along with fungal diseases. There are many kinds of actinomycetes, which are widely distributed in nature, and there are actinomycetes in air, soil and water sources. A few strains are pathogenic to humans, the most important of which is actinomycetes. The actinomycetes are the parasitic bacteria in the normal oral flora of humans, causing oral mucosal damage during tooth extraction, trauma or other causes. Actinomycetes can be invaded by wounds, or they can enter the gastrointestinal or lungs by swallowing or inhaling the carrier material. Therefore, actinomycosis mainly occurs in the neck and chest and abdominal organs. basic knowledge Sickness ratio: 0.001%-0.002% Susceptible people: no special people Mode of infection: contagious Complications: periostitis, lung abscess, sepsis, pleural effusion

Cause of actinomycosis

(1) Causes of the disease

The pathogens causing human actinomycosis are mainly actinomycetes, actinomycetes and actinomycetes, and arachnoids and bifidobacteria of the genus A. Bifidobacterium Escherichia coli, actinomycetes belong to prokaryotic microorganisms, have well-developed hyphae and spores, but the hyphae are separated by a single cell structure; no fixed nuclei are found in hyphae and spores, only nuclei The plastids are dispersed in the cytoplasm; the cytoplasmic granules, chloroplasts and other organelles, the chemical composition of the cell wall is similar to that of bacteria (mainly peptidoglycan compounds form a network complex) and is significantly different from fungi, the main components of the nucleosome DNA, but not the component of the eukaryotic chromosome-specific histones; sensitive to lysozyme and antibiotics such as penicillin, but resistant to fungal drugs, due to actinomycetes producing hyphae and spores, much like fungi, and because of them The clinical manifestations of the disease caused are difficult to distinguish from fungal diseases. Therefore, according to traditional habits and clinical needs, actinomycosis is put into fungal diseases. These pathogens are anaerobic bacteria or micro-aerobic, often A normal flora in the body, especially in the oral cavity, can be seen in the oral cavity. If there is trauma, infection can occur after surgery, often infected with bacterial infection after infection, damage gradually passes through the sinus from the center, spread to the surrounding, invading the skin, subcutaneous Tissue, muscle, fascia, bones and internal organs can be transmitted through the digestive tract and trachea, and very few are disseminated through blood.

(two) pathogenesis

The actinomycetes are established in the oral microbial plexus by adhesion to the oral surface, especially the dental plaque. The plaque is a thin layer covered with prion and glycoprotein on the glaze. Adhesion is through the protein. Obtained by the complex stereochemical reaction of proteins and the interaction of lectin saccharides, which can also mediate oral actinomycetes and Streptococcus milleru group S. sanguis and Cellular coaggregation of other oral flora, which may partly explain why actinomycetes are often multi-microbial, and in the neck, thoracic, and central nervous system (CNS) abscesses, why are they often "concomitant" The oral flora, the "concomitant" flora may play a synergistic role in the infection, because it can maintain the hypoxic tension environment required for the growth of actinomycetes, bacteria must be infected by teeth, manipulation or aspiration of dental infection debris Mucosal damage, into the tissue, can cause disease, can also enter the abdominal cavity through the lower digestive tract perforation, women can have ascending infection in the reproductive tract.

Actinomycetes infection simultaneously stimulates purulent and granulomatous inflammatory reactions with severe fibrosis. Plasma cells and multinucleated giant cells can often be seen in the lesions. Large macrophages can appear around the suppuration center. The cytoplasm is foamy. In this way, the infection develops through the fascia and eventually forms a drainage sinus. Especially in the case of pelvic and abdominal infections, although the damage is typical of sulfur particles and drainage sinus, but not all, the particles are bacterial sand-like aggregates. The diameter is 1~2mm, the center stain is basophilic, with acidophilic release line, and the surface is finished with a bead-like "rod". The calcium phosphate contained may be the product of the host and bacterial phosphatase.

Actinomycosis prevention

1. Because actinomycosis is the most endogenous infection, the large number of immunosuppressive applications are often an important predisposing factor, so try to avoid the large number of applications of immunosuppressants.

2. When the body's resistance is reduced, it causes actinomycosis, and strengthening the body to improve immunity has great significance for actinomycosis.

Cyclobe complications Complications periostitis lung abscess sepsis pleural effusion

Face, neck actinomycosis, late can cause periostitis and osteomyelitis, abdominal actinomycosis, can also affect other organs of the abdomen such as stomach, liver, kidney, etc., or affect vertebrae, ovary and bladder, chest Or blood line spread to the central nervous system, chest actinomycosis, may be associated with pleural adhesions and pleural effusion, and can break through the chest wall to form a fistula, can also affect the pericardial pericarditis, mediastinal involvement, can cause breathing or swallowing difficulties Severe cases can lead to death, lung abscess and pleural effusion, brain-type actinomycosis, localized type, still visible compression of the internal carotid artery, the brain, the proximal end of the anterior artery is narrowed, diffuse, can also be Epidural abscess, skull osteomyelitis, etc., skin-type actinomycosis, can also invade deep tissues, localized by fibrosis, scar formation and very hard, actinomycetes occasionally invade the bloodstream, causing actinomycete sepsis and other Organ disease.

Symptoms of actinomycosis Common symptoms Nausea fever with cough, slightly... Night sweats

Actinomycosis can occur in any tissue of the human body. According to statistics, 60% to 63% occur in the face and neck, 18% to 28% in the abdomen, 10% to 15% in the chest, and only 8% in other parts. Left and right, clinically, generalized actinomycosis is generally divided into the following types:

Cervical actinomycosis

This type is most common, occurs in the neck junction and mandibular angle, alveolar ridge, initial local mild edema and pain or painless subcutaneous mass, and then the mass gradually hardens, increasing like a wooden board, and with The skin adheres, the surface of the skin is dark red or purple, and then the mass softens to form an abscess. After the ulceration, multiple sinus is formed, and the discharge has an odor. In the pus, a diameter of 1 to 2 mm is lobulated. Yellow solid "sulphur particles" have diagnostic value. If there is no secondary infection, the pain is generally not serious, and the local lymph nodes are not swollen. The general health of the patient is not affected, and the discomfort is very light, but it may occur due to the masticatory muscle involvement. The teeth are tight, the chewing function is affected, and periostitis, osteomyelitis, and bone destruction can occur in the advanced stage.

2. Chest type actinomycosis

The most common sites of infection are the hilar and lung base. In the first few weeks, there are irregular fever, cough, sputum, chest pain, but no hemoptysis. As the disease progresses, small abscesses appear in the lungs, and the sputum is mucinous. It indicates that the lung parenchyma is damaged. When the pleura is involved, obvious chest pain and pleural effusion may occur. When the infection and the chest wall form nodules, abscesses, and penetrate the chest wall and the skin, multiple sinus is formed. The sulphur has a typical "sulphur." "granules", patients may experience progressive weight loss, fever, fatigue, anemia, night sweats and difficulty breathing.

3. Abdominal actinomycosis

Occurs in the ileocecal department, the clinical manifestations are similar to acute, subacute or chronic appendicitis, and then, irregular lumps with unclear borders appear in the ileocecal area or other parts, similar to cancer, the disease continues to develop, and the abdominal mass becomes larger and Adhesive with the abdominal wall, can form multiple sinus after piercing the abdominal wall, "sulphur particles" can be seen in the pus flowing out, patients may have symptoms such as chills, fever, night sweats, fatigue, weight loss, nausea, vomiting and colic. Actinomycetes infection can also be seen in the liver, gallbladder and fallopian tubes. The onset is concealed and the clinical manifestations are related to the affected organs. If the liver is involved, liver enlargement and jaundice may occur. When the spine is spread to the spine, the spine may be destroyed, the spinal cord may be compressed, and the psoas muscle abscess may be generated, and the chest cavity may be ascended to the chest, or the blood may be transferred to the central nervous system and the like to cause the corresponding lesion. Abdominal actinomycosis is difficult to detect before the formation of the abdominal sinus, so a considerable number of cases were diagnosed at the time of laparotomy.

4. Skin type actinomycosis

It can occur in limbs, trunk, buttocks, face, etc. Actinomycetes invade the skin and subcutaneous tissue along the wound, and begin to form subcutaneous nodules in the local skin. After that, the nodules soften, rupture, form sinus, and can form around. Multiple satellite-like subcutaneous nodules, the latter soften, forming multiple interspersed sinus after rupture, often discharge light yellow purulent material in the sinus, which can be seen as "sulphur particles", the disease develops slowly, can penetrate deep tissues, The formation of granulation and fibrous tissue can be a hard plate-like scar. If the lesion is limited, the patient often has no systemic symptoms, local pain, and edema is not obvious.

5. Brain-type actinomycosis

This type is rare, clinically divided into localized brain abscess type and diffuse type, localized abscess is more common in the cerebral hemisphere, a few occur in the third ventricle and posterior cranial fossa, can be single, multiple or multiple brain abscess and granulation Swelling, outsourcing with thick film, mainly manifested as signs of brain occupying lesions, such as elevated intracranial pressure, cranial nerve damage, headache, nausea, vomiting, diplopia, optic nerve head edema, etc., often no fever, total white blood cells And classification is normal, cerebral angiography can be seen in space-occupying lesions, some cases may have upper carotid artery and brain, anterior stenosis of the anterior artery, diffuse lesions for a small number of patients with brain abscess invading the ventricle, causing meningitis, at this time patients In addition to the manifestations of localized brain abscess type actinomycosis, it also shows symptoms similar to bacterial meningitis, signs, epidural abscess in some cases, skull osteomyelitis, and a large number of cervical mesenchymal lesions can spread directly To the skull, ventricles.

6. Actinomycosis in other tissues

These include conjunctival and lacrimal ductitis; female genital actinomycosis, but also primary infections of the bladder, kidney, tibia, heart valve, bones, joints, etc.

The early diagnosis of actinomycosis is conducive to early treatment and improvement of prognosis. However, due to the extensive location of the disease and various clinical manifestations, the diagnosis must rely on medical history, clinical manifestations and auxiliary examination. In case of the following conditions, actinomycosis should be considered. .

1 neck and face, the nature of the chest mass is unknown.

2 bronchitis, pulmonary infection treatment is not good, lung abscess, pleural empyema cause is unknown.

3 abdominal gastroenteritis, ulcer perforation, or abdominal fistula after the formation of fistula in the incision site, when the tumor, at this time should try to absorb the specimen for actinomycetes, or add pathological examination.

Examination of actinomycosis

Pathogen inspection:

1. Direct microscopic examination: Gram staining of granules, blue mycelial masses and rods can be seen, and pus smears may also find small and short branch-like hyphae, which are negative for acid-resistant staining, and note that acid-fast staining of Nocardia Positive, Streptomyces spores, can be identified.

2. Culture: It is more difficult, the particles must be washed with sterile saline several times to remove bacteria, then crushed with a sterile glass rod, streaked on brain agar infusion blood agar, into CO2 anaerobic bacteria cylinder, 37 Only culture in °C.

3. Histopathology: early local leukocyte infiltration, formation of small abscess, piercing to form sinus, each sinus can communicate, the body fascia, pleura, diaphragm, bones, etc. can not prevent its development, near the suppuration area can be chronic Granulation tissue proliferation, may be lymphatic cells, plasma cells, tissue cells and fibroblasts infiltration, local tissue can also be glass-like degeneration, hard plate-like hardening, "sulphur particles" can be seen inside the abscess, 100 ~ 300m diameter HE staining is homogeneous in the center, and there are palisade-like short rod-like cells around it.

Diagnosis and identification of actinomycosis

The disease should be differentiated from tuberculosis, tumor, liver abscess, psoas abscess, osteomyelitis, appendicitis, fungal foot disease, grape plague, nocardiosis.

Ulcerative skin tuberculosis: more common in children, occurs in the neck, underarms, chest and groin, early skin lesions are soy-sized subcutaneous nodules, removable, hard, painless, adhesion to the skin, followed by cheese Necrosis, rupture, fistula formation, atrophic short marks after the recovery, histopathological examination for tuberculous granulomatous changes.

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