Pyoderma gangrenosum

Introduction to gangrenous pyoderma The disease is characterized by destructive, necrotizing, non-infectious skin ulcers, clinically present with sputum-like nodules, pustules or hemorrhagic bullae, and early stage erythema or pustules. This disease can be attributed to vasculitis. basic knowledge Sickness ratio: 0.001%-0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: ulcerative colitis

Causes of gangrenous pyoderma

(1) Causes of the disease

It has been confirmed that patients with this disease have defects in delayed response to DNCB, candida and streptokinase, which may explain when the reticuloendothelial system is extremely low, and when there is slight damage or injury, skin lesions may occur, and new lesions may also occur. This hypersensitivity reaction can be caused by acupuncture, especially in the acute phase of the disease and near the skin lesion. It has been confirmed that there is a serum cutaneous necrosis factor in skin of guinea pigs that can cause skin necrosis, but its specificity is unknown. Evidence of defects in the immune mechanism is: many patients have gamma globulin disease, atypical protein disease, T cell dysregulation or phagocytic defects.

(two) pathogenesis

The pathogenesis of this disease is unknown, may belong to the Shwartzman reaction, many patients with this disease with low or abnormal immune response, indicating that the disease is related to defects in the immune system, some authors reported 4 patients, showing no skin reaction.

Gangrenous pyoderma prevention

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Gangrenous pyoderma complications Complications ulcerative colitis

Half of the cases are associated with ulcerative colitis, colitis or with or after the lesion. In addition, the disease is also associated with many diseases with arthritis, such as Behcet syndrome, the most important It is interesting to note that this disease is associated with diseases of the immune system, including congenital and acquired hypogammaglobulinemia, which is more common, including IgA, IgG or IgM.

Symptoms of gangrenous pyoderma Common symptoms Herpes blush erythrocytosis Dry toe end necrosis

1. The tender erythema of the nodule, initially red, and then the center becomes blue, eventually forming an ulcer.

2. One or more blisters, pustules, similar to acne, folliculitis, transient acanthosis dermatitis or herpetic dermatitis, etc., both lesions can occur at the same time, can also change each other, skin lesions can occur In normal skin or parts of the original skin disease.

The primary skin lesions gradually edema and rapidly form ulcers. The boundary is clear, the edges are light blue, often thickened and raised, sometimes with unevenness and sneak damage. The base of the central ulcer is red, varying in depth, like a crater, with a surface attached. Stinky yellow-green pus, surrounded by red faint around the ulcer, due to capillary and venous thrombosis of the skin and subcutaneous tissue, the lesions are continually expanding to the periphery, the ulcers vary in size, small as soy beans, the larger diameter is available 10cm or more, the number is more, up to more than 100, the skin lesions are more painful, and there is also long-term painlessness. Some cases can heal themselves, leaving atrophic sieving scars, often without lymph nodes or lymphatic lesions. .

Deep dermis or vesicular bullous type is also not uncommon. This type of skin lesions are mostly single and accompanied by other symptoms. Hemorrhagic bullous type is usually bullous, superficial and painful, and blister fluid can reach 0.5 L or more. This type is often associated with acute leukemia and other myeloproliferative diseases, but 15% of cases have no such related diseases. In some cases, Behcet syndrome is characterized by oral-genital ulcers or superficial thrombophlebitis.

Atypical cases are similar to fulminant purpura, neutrophilic dermatosis, nodular erythema or nodular vasculitis.

Skin lesions can accumulate throughout the body, mainly accumulating calves, thighs, buttocks and face, lips and oral mucosa, and even pustules and erosive blisters in the eyelids and conjunctiva, 20% of cases have a homomorphic response.

Symptoms of toxicemia and long-term fever can occur during the active period of the disease. The rapid resolution of these systemic symptoms depends on the application of corticosteroids, and the body temperature can be reduced to normal within 24 hours.

Ulcerative pyoderma ulcers often recur, and can last for several years, but the general condition is still good.

Half of the cases are associated with ulcerative colitis, colitis or with or after the lesion. In addition, the disease is also associated with many diseases with arthritis, such as Behcet syndrome, the most important It is interesting to note that this disease is associated with diseases of the immune system, including congenital and acquired hypogammaglobulinemia, which is more common in monoclonal gamma disease, including IgA, IgG or IgM disease, and has been reported with bone marrow. Tumor-related, hemorrhagic bullous gangrenous pyoderma is associated with myeloid proliferative diseases such as leukemia, polycythemia, and myeloid fibrosis. The disease overlaps with neutrophil-related diseases, such as under the horny layer. Pustular dermatosis and so on.

Examination of gangrenous pyoderma

Histopathology: no specific change, manifested as aseptic abscess, including venous and capillary thrombosis, hemorrhage, necrosis and mast cell infiltration, coagulation is an important manifestation, showing lymphocytic vasculitis at the edge of activity, suggesting blood vessels The endothelium is an early target organ. Early lesions are similar to Behcet's disease and neutrophilic dermatitis. They are also partially similar to leukocyte-ruptured vasculitis. Infiltrating cells have more polymorphonuclear leukocytes, epithelial cells and giants. Cells, especially in chronic cases, have significant monocytes, even epithelial-like hyperplasia, and pathological examination can rule out amebiasis and deep fungal infections.

Diagnosis and diagnosis of gangrenous pyoderma

diagnosis

Diagnosis relies on clinical morphology, painful ulcers on the stalk edge, and yellow-green pus with odorous odor.

Differential diagnosis

1. Behcet's disease is sudden onset, the pustules are lymphocytes, no ulcers, no scar after the skin lesions.

2. Postoperative progressive gangrene is more common in the chest or abdomen, often a single lesion, which can be isolated from the lesions by micro-aerobic streptococcus, which is sensitive to antibiotics.

3.Meleney gangrenous septic ulcer is similar to this disease, but infections caused by Clostridium are not common today.

4. Wegener granulomatosis has multiple organ damage, lesions pleomorphic, respiratory tract is a good site, C-ANCA positive.

5. The distribution of fulminant purpura lesions is extensive and progresses rapidly.

6. Amoebic disease, cryptococcosis and blastomy can be confirmed by microbiological and pathological examinations.

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