etiology of primary skin tuberculosis syndrome, what are the causes of primary skin tuberculosis syndrome
Etiology of primary cutaneous tuberculosis syndrome: Mycobacterium tuberculosis is inoculated on the skin of healthy people without natural or artificial immunity
First, the cause of the disease
Mycobacterium tuberculosis is a pathogenic bacterium causing skin tuberculosis, which is an acid-fast bacillus, and its acid-fast staining is red. Skin tuberculosis can be caused by human or bovine tuberculosis infection.
The infection route of this disease is divided into: due to skin or mucous membrane injury, Mycobacterium tuberculosis directly invades skin or mucous membrane and causes disease.
Second, the pathogenesis
The pathogenicity of Mycobacterium tuberculosis is related to the inflammatory reaction caused by the proliferation of bacteria in tissues and cells, the toxicity of bacterial components and the hypersensitivity of the body to some bacterial components.
When Mycobacterium tuberculosis invades the skin, it is first swallowed by neutrophils, and continues to multiply in it, and then carried deep into the body by neutrophils. The early stage is neutrophil reaction, accompanied by necrotic area and a large number of Mycobacterium tuberculosis. When leukocytes break, bacteria disperse and are swallowed by macrophages in the body. Bacteria continue to multiply in macrophages, thus causing cell infiltration and forming chronic granuloma. When sensitized lymphocytes come into contact with Mycobacterium tuberculosis or phagocytes containing Mycobacterium tuberculosis, That is, a series of immune effector factors are released, Mainly macrophage migration inhibitory factor (MIF), macrophage activating factor (MAF) and chemokines, Attracting macrophages to gather around Mycobacterium tuberculosis and sensitized lymphocytes enhances the activity of macrophages, and intracellular digestive enzymes such as lysozyme and hydrolase increase to become activated macrophages, which can kill and eliminate Mycobacterium tuberculosis hidden in cells. Caseous necrosis gradually decreased, and Mycobacterium tuberculosis also decreased obviously. At this time, tuberculin test changed from negative to positive.