Hemispherical blue-black nodules on the face

Introduction Capillary or venous thrombosis clinical manifestations: hemispherical or mildly lobulated nodules, medium hardness, ranging from 2 to 10 mm in size, blue-black in color. There are red or brown pigmentation around it. The damage suddenly or gradually occurs. Occurs in the face, but can also affect other parts including oral mucosa. The importance of this disease is mainly clinically similar to malignant melanoma.

Cause

(1) Etiology: The cause of sarcoidosis is not known, and may be related to various factors as follows.

1. Genetic factors:

Sarcoidosis may be a polygenic genetic disease. It is currently recognized that HLA-A1, HLA-B8, and HLA-DR3 in leukocyte histocompatibility antigen (HLA) are closely related to the pathogenesis of sarcoidosis. US Teistein reports that about 10% of American patients with sarcoidosis have a family history. Moreover, the odds of single-oval twins suffering from sarcoidosis are much higher than those of double-oval twins.

2. Environmental and occupational factors:

Japan reported that the incidence of cold Hokkaido sarcoidosis is high. The incidence of sarcoidosis is high in the southeastern United States. It has been reported that sarcoidosis is prone to occur in the winter-spring season. Metallic aluminum, zirconium, hafnium, talc, pine pollen, clay, etc. may also be involved in the occurrence of this disease.

3. Infection factors:

Certain viruses, spirochetes, Propionibacterium acnes, Mycobacterium tuberculosis, non-tuberculous mycobacteria, and Mycoplasma genus may induce this disease. However, this disease responds well to hormone therapy, indicating that infection does not persist in the pathogenesis of sarcoidosis, otherwise it will cause the spread of infection. Therefore, the causal relationship between infectious factors and sarcoidosis has not yet been confirmed.

4. Immunological factors:

The Th1/Th2 imbalance may be related to the onset of sarcoidosis. In most cases, the local helper T cells are mainly Th1 (CD4+) cells; only a few cases are dominated by Th2 (CD8+) cells. It has been suggested that abnormalities in the quality or quantity of T lymphocyte receptors (TCRs) are associated with the development of sarcoidosis.

(two) pathogenesis:

1. The formation of sarcoidosis granuloma requires at least three main links:

(1) Exposure to an unknown antigen.

(2) Cellular immune responses against unknown antigens: including antigen presenting cells and antigen-specific lymphocytes.

(3) Immune effector cell aggregation: These aggregated cells mainly have two sources: one is redistribution in the lung tissue by cells in the blood circulation; the other is local proliferation of these cells in the lesion. Because these cells locally aggregate and release a variety of cytokines, they promote more non-specific inflammatory responses.

2, sarcoidosis granuloma formation process: more considered to be a cell-mediated type IV allergic reaction.

(1) An antigen stimulates macrophages to produce interleukin I. When it is exposed to antigen again, T lymphocytes are activated. With the help of interleukin II, T lymphocytes proliferate to produce a variety of lymphokines. , causing macrophages to accumulate in the lesion.

(2) In turn, proliferating alveolar macrophages release fibronectin, which stimulates fibroblast proliferation and fibrosis of granulomatous lesions.

an examination

Related inspection

Sarcoidosis antigen (Kveim) test blood routine

Clinical manifestations:

Hemispherical or mildly lobulated nodules of medium hardness, ranging in size from 2 to 10 mm, with a blue-black color. There are red or brown pigmentation around it. The damage suddenly or gradually occurs. It occurs on the face, but it can also affect other parts, including the oral mucosa. The importance of this disease is mainly clinically similar to malignant melanoma.

Differential diagnosis

Differential diagnosis of facial hemispheric blue-black nodules:

Special facial paralysis: tuberous sclerosis, also known as Bourneville disease, is characterized by seizures, mental disorders and special facial paralysis. It can be differentiated from other diseases that can cause epilepsy and mental disorders in infants and young children.

diagnosis:

According to clinical manifestations, combined with histopathology can be diagnosed.

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