Actinomycosis is a chronic specific infectious disease in which a dense infiltration develops on the skin and subcutaneous tissues, which tends to progress, in which specific druses are detected.
Etiology and pathogenesis of actinomycosis
The causative agent of the disease is Actinomyces Israeli fungi, gram-positive fungal microorganisms from the Fungi imperfecti group, as well as Actinomyces naestundii and Arachnia propionica fungi, which are vegetative on the stalks of barley, rye and other cereals. These fungi are widespread in nature.
When inhalation of dust containing these fungi and their spores, the pathogen enters the lungs. Infection also occurs when the pathogen enters the mucous membranes of the oral cavity, intestines and bronchi, or when chewing (swallowing) grains of cereals. Fungi can also be present in the oral cavity as saprophytes, especially in carious teeth and crypts of enlarged tonsils. Depending on the route of infection, the neck-facial, intestinal or pulmonary forms of actinomycosis develop.
After infection, chronic inflammation develops in the tissues with the formation of a granuloma having a wood texture, which progressively grows, involving new tissues in the process. In the depth of the granuloma, there are foci of softening, containing liquid pus and drusen of the fungus, after the breakthrough of which sinuous fistulas or ulcers are formed. Regional lymph nodes do not increase. They increase only in the case of the accession of a secondary purulent infection, as a result of which phlegmons, abscesses and regional lymphadenitis develop. The germination of blood vessels in the granuloma can lead to the generalization of infection, i.e., to the development of specific actinomycotic sepsis.
Clinic of actinomycosis
The incubation period lasts several weeks, sometimes months. Solid infiltrates (granulomas) are most often (in 50% of cases) formed on the lower jaw and neck. The disease develops slowly, gradually, without acute manifestations. The very first symptom of it is the reduction of the jaws, on which over time there is a thickening and swelling of the masticatory muscles. Subsequently, subcutaneous fatty tissue and skin, sometimes bone, are involved in the pathological process, as a result of which a very dense immobile infiltrate (granuloma) is formed in them. During this period, this infiltrate should be differentiated from tuberculous lymphadenitis and tumors. Gradually, the skin is involved in the process in the area of the angle of the lower jaw and neck, which acquires a blue-purple color; infiltration wood consistency, soldered to the skin and deeper tissues is palpabled on it. Over time, in the area of infiltration, multiple sinuous fistulas appear, from which pus is released. At the same time, the pus is liquid, odorless, containing small grains (fungal druses). The skin around the fistula becomes dark blue or purple.
If the lungs are involved in the pathological process, perifocal pneumonia, abscess and secondary bronchiectasis develop in their lower parts. In this case, the process extends to the chest wall and diaphragm, as a result of which intercostal fistulae are formed. When acginomycosis of the lung a specific granuloma forms in the lung tissue. Growing, it draws into the process the parenchyma, pleura, bronchi and pulmonary vessels. Infiltration (granuloma) can sprout through the pleura and chest wall, extending to the diaphragm and thoracic mediastinum. Disintegration of the infiltrate leads to the formation of abscesses and cavities in the lungs. Pus containing fungal drusen can drain with sputum in case of infiltration into the bronchus or out through the fistula. This process lasts for months and even years and leads to the development of severe pulmonary fibrosis. At the initial stage, the clinical picture of lung actinomycosis resembles chronic bronchopneumonia. The presence of infiltrate in the lung is determined by X-ray. X-ray methods, computed tomography, bronchoscopy and the characteristic features of the clinical course of the disease allow specialists to exclude tuberculosis or lung cancer and diagnose actinomycosis.
Diagnosis of actinomycosis
In advanced cases, when the process spreads to the chest wall with a clinical picture of skin lesions characteristic of actinomycosis, the diagnosis is beyond doubt. The identification of drusen in the sputum, pus and tissues obtained during bronchoscopy and thoracoscopy (in case of involvement in the process of bronchi or pleura) is extremely important for the diagnosis.
The most common site of actinomycosis in the intestine is the cecum and the vermiform process. Infiltrate captures the entire intestine, germinates through the peritoneum and the abdominal wall. After its disintegration, ulcers are formed on the mucous membrane, sometimes – multiple ulcers and fecal external fistulas. Infiltration can break into nearby organs – the bladder and kidney, as well as in the retroperitoneal space. When palpating the abdomen, it is defined as a very dense tumor formation (immobile during germination in the abdominal wall or nearby organs).
Differential diagnosis of actinomycosis
Actinomycosis must be distinguished from tuberculous lymphadenitis, malignant and benign tumors, and also from pulmonary tuberculosis. For the diagnosis, intracutaneous tests and serological reactions with actinolysate are carried out, pus is examined for the presence of drusen in it. The tumor should be distinguished from the appendicular infiltrate, which occurs immediately after an attack of acute appendicitis and which, after anti-inflammatory treatment, is rapidly reversed.
Treatment of actinomycosis
Long-term combination therapy is prescribed. Actinomycosis of the face and neck is curable. Its prognosis even with the launched forms is favorable. In case of actinomycosis of the intestines and lungs, the conservative therapy is performed. In the initial stages of the disease, the prognosis is favorable. If conservative therapy is ineffective, surgical treatment is recommended – resection of the intestine or lung in combination with conservative therapy. If the disease becomes chronic, if the process spreads to other organs or if severe purulent complications develop (purulent pleurisy, mediastinitis, retroperitoneal phlegmon), emergency palliative operations are performed – opening of the phlegmon, draining of the thoracic mediastinum and the pleural cavity. The prognosis is unfavorable.