Blastomyces dermatitidis
Introduction
Introduction to dermatitis buds Blastomycosisdermatitidis, also known as North American bud disease, is a chronic suppurative, granulomatous lesion mainly caused by lung, skin and bone caused by dermatitis buds. This disease is mainly prevalent in North America, in the United Kingdom. There are also a few sporadic distributions in Mexico and other places. However, patients used to live in the United States or have been exposed to the bacteria. In China, in 1989, Wu Shaoxi and others discovered a case of skin-type infection in the United States. In 1999, Guo Runshen and others reported this. The disease is a local infection. The disease occurs in men aged 40 to 60 years old. After the spore enters the alveoli, it is engulfed by macrophages, causing inflammatory reactions including polymorphonuclear leukocyte infiltration, and then granuloma formation, which can be characterized as purulent or suppurative granulomatous lesions. The clinical manifestations are primary pulmonary dermatitis germination. , dermatitis dermatitis, disseminated dermatitis buds, combined with fungal examination and lung examination to help diagnose, amphotericin B is an effective treatment for blastomycosis. basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: brain abscess meningitis prostatitis
Cause
Dermatitis bud fungus
(1) Causes of the disease
It is a kind of chronic suppurative and granulomatous lesions mainly caused by lung, skin and bone caused by dermatitis buds. The dermatitis buds are biphasic bacteria, and the dermatitis is called dermatitis. The true classification belongs to the ascus.--.
(two) pathogenesis
The bacteria can be parasitic on soil, moist and organic matter. After the spores enter the alveoli, they are engulfed by macrophages, causing inflammation, including polymorphonuclear leukocyte infiltration, and then granuloma formation, which can be expressed as suppurative or suppurative granulation. Swollen lesions, trauma caused by primary skin infections, secondary infections spread from other lesions, often in a single or group, developed into ulcerative verrucous granuloma after weeks to months, the edge is high 1 ~ 3cm, clear boundaries, purple sputum, a small number of other parts from the blood circulation to the bones, brain and other parts, the digestive tract is rarely involved, the spine, ribs, tibia and femur often involved, manifested as osteomyelitis, periostitis Even septic arthritis has pain and dysfunction.
Prevention
Dermatitis bud prevention
It is an important measure to prevent skin damage, prevent inhalation of bacteria and dust, and avoid entering popular areas.
Complication
Dermatitis buds complications Complications, brain abscess, meningitis, prostatitis
Brain abscesses and meningitis, liver spleen pyogenic granuloma and prostatitis also occur frequently.
Symptom
Symptoms of dermatitis germination common symptoms pleural effusion skin granuloma periostitis meningitis brain abscess
1. Primary pulmonary dermatitis bud bacterocytosis inhalation of spores into the alveoli after phagocytosis by macrophages, causing inflammatory reactions including polymorphonuclear leukocyte infiltration, and then granuloma formation, can be expressed as suppurative or suppurative granulomatous lesions, Bacterial yeast cells are seen in lung macrophages, with substantial infiltration of pneumonia, lymphangitis and lymphadenitis.
2. Skin dermatitis Bud sclerotia occurs in exposed areas such as face, hand, wrist, lower limb or skin mucosa junction such as mouth, throat, tongue, etc., can also be located in non-exposed areas, develop ulcers after weeks to months Sickle granuloma, the edge is 1 ~ 3cm high, the boundary is clear, with purple sputum, often misdiagnosed as basal cell carcinoma, but the edge often has microabscess, ulceration after fibrosis, ulcer central biopsy often can not find bacteria It can only be found at the edge of the event.
3. Disseminated dermatitis germination is mostly from the lungs, a small number of other parts from the blood circulation to the bones, brain and other parts, the digestive tract is rarely involved, the spine, ribs, tibia and femur often involved, manifested as osteomyelitis , periostitis and even septic arthritis, pain and dysfunction, brain abscess and meningitis, liver spleen pyogenic granuloma and prostatitis also occur.
Examine
Examination of dermatitis buds
Mycological examination:
1. Direct microscopic examination of sputum, pus, bone marrow, blood, cerebrospinal fluid, pleural effusion, urine, biopsy or cadaver tissue specimens for direct examination.
2. The fungal culture was cultured on a sand castle agar at room temperature, and began to grow as a yeast-like film, followed by a fine-stinged hyphae in the center, which gradually increased to form a central ring.
Histopathology: visible epithelioid granuloma or chronic suppurative necrosis and fibrosis, depending on the condition, such as chronic epithelial-like hyperplasia, but in the systemic system of infection can be seen purulent, necrotic and many bacteria, the bacteria About 8 ~ 12m diameter, sometimes up to 20 ~ 30m, wall thickness and obvious, like double wall or birefringence, cytoplasm condenses from the cell wall to form a gap, HE staining can see cytoplasmic multinuclear features, primary lung The earliest infection is an inflammatory cell reaction, and many neutrophils are seen. Sometimes it is chronic granulomatous with purulent area or epithelioid cell granuloma. There are many small abscesses, including neutrophils, debris and a few giant cells. And visible bacteria, such as hyperplasia can be tumor-like, only to find a micro-abscess can help diagnose.
Diagnosis
Diagnostic identification of dermatitis buds
Diagnostic criteria
For patients from endemic areas, especially those who are not responding to anti-tuberculosis treatment, it is necessary to combine fungal examination and lung examination to help diagnose the disease. For other 50% of patients with extrapulmonary type, especially chronic skin granuloma, it can be combined with pathology. Fungal examination to help confirm the diagnosis.
Differential diagnosis
The disease should be differentiated from tuberculosis, sarcoidosis, actinomycosis, nocardiosis and other bacterial chronic granulomatosis.
