外阴阿米巴病

　　1、发病原因

　　女阴的阿米巴感染常常是通过性交而直接感染。阿米巴原虫不能侵犯完整的皮肤，只有当皮肤受到擦伤、裂口、切伤或外科创口进入，才能引起皮肤黏膜的损害。人体通过饮食，吃下被阿米巴包囊污染的食物或水，在结肠内形成病灶，并产生阿米巴痢疾，阿米巴痢疾可由擦伤的肛门或外阴直接蔓延，也可通过内裤、毛巾、浴具等生活用品传播。婴儿的外阴阿米巴病常继发于严重的阿米巴痢疾。

　　2、发病机制

　　阿米巴属Sarcodina亚门，通过伪足运动，以二分裂殖方式无性繁殖。溶组织阿米巴又称阿米巴原虫，为人体惟一的致病型阿米巴，它的生活过程中有两个不同的形态，即滋养体和包囊。在中性或弱碱性环境中，包囊会转化为滋养体。当局部的环境对阿米巴原虫不利时，它们会形成包囊并长期存活，但一般不会导致临床的疾病。包囊对外界抵抗力强，是该病的一个重要传染源，也是传播疾病的主要形态。滋养体能引起组织的溶解，使组织发生坏死而引起病变，病原虫一旦侵入后，具有蛋白水解酶活性作用的病原虫就能使宿主组织产生广泛性溶解性坏死而成脓肿及溃疡。

　　常合并阿米巴宫颈炎，肠道阿米巴病。

　　1. Amoebic cervicitis is mainly manifested by increased vaginal discharge, which is purulent, purulent and bloody, or serous with a foul smell. Women with vaginitis often have vaginal pain, burning sensation, without vulvar itching. Gynecological examination and vaginal speculum examination show the cervix deformed into worm-eaten ulcers and necrotic tissue, with elevated edges resembling volcanic craters. There is dirty grayish yellow secretion covering the surface, with yellowish purulent or bloody mucous, which is easy to bleed upon palpation.

　　2. Amoebic dysentery: The onset is generally slow, with abdominal discomfort, loose stools, and sometimes diarrhea, occurring several times a day. Sometimes constipation may also occur. During diarrhea, the stools may have a slight amount of pus and mucus resembling dysentery. As the lesion progresses, the dysenteric stools may increase to 10 to 15 times a day or more, accompanied by urgency, increased abdominal pain, and bloating. The cecum, transverse colon, and especially the rectum may have tenderness, sometimes resembling ulcerative colitis or appendicitis. General systemic symptoms are usually mild, quite different from bacterial dysentery. Stool examination may show a small or large number of trophozoites, and the stools have a foul smell of decay.

　　1. Vulvar amoebic ulcer

　　It primarily manifests as localized hard pustules, followed by redness and swelling, which then rupture to form ulcers. The ulcers have a strong stinging pain, and there are multiple circular or irregular ulcers with clear boundaries. Some edges may flip outwards, while the inner edges may indent inwards, forming deep tunnel-like ulcers. The ulcers rapidly spread to the periphery and deep areas, merging into large ulcers several to tens of centimeters in size and showing extensive necrosis. The ulcer surface is dark red granulation tissue, covered with necrotic tissue and pus, with a foul smell. Some individuals may have fibrous tissue proliferation, presenting as tumor-like protuberances with hard texture and溃烂 surface. Weak patients may experience more destructive effects, and inguinal lymphadenitis may occur.

　　2. Vulvar amoebic granuloma

　　On the basis of ulcers, the granulation tissue at the bottom of the ulcer grows into proliferative granuloma, forming papillary nodules or cauliflower-like protuberances with uneven surface, which are relatively hard and tend to bleed upon contact. There is purulent and bloody secretion on the surface, with a foul smell. Amoeba protozoa can be found in the secretion.

　　One, precautions:

　　1. Timely and proper treatment of amoebic dysentery or liver abscess is an important premise for preventing the occurrence of genital amoebiasis.

　　2. Pay attention to improving nutritional status and strengthening physical fitness.

　　3. Both personal dietary and environmental hygiene should be paid attention to, as well as the transmission between sexual partners. Especially for asymptomatic carriers, timely treatment should be sought to prevent transmission to others.

　　Two, prognosis:

　　Without treatment, this disease can lead to fatal consequences.

　　Three, the diagnosis of this disease can be made by microscopic examination of the scraping material from the lesion site, or by culturing amoebae with exudates.

　　In addition, serological tests also help in diagnosis.

　　1. On fresh smears, Amoeba protozoa can be observed at 20～40μm, with active pseudopodia. During HE staining, large cell bodies can be seen, with cytoplasm containing fine pink granules. By observing the engulfed red blood cells in the cytoplasm, it is possible to distinguish whether the Amoeba protozoa is in the pathogenic trophozoite stage. When intestinal amoebiasis is suspected, fecal examination should be performed.

　　2. Serological examination for amebiasis is not widely used in clinical practice because the antibody response in serum often appears several weeks after the ameba invades the tissue, and the antibody detection of asymptomatic carriers is often negative. The detection methods include indirect hemagglutination, immunofluorescence antibody, and enzyme-linked immunosorbent assay, etc. The antibody titer in serum can persist for several months to several years after recovery, so it can be used to assist in diagnosis and epidemic screening.

　　Use vegetable oils, commonly cooked by boiling, steaming, cold salad, roasting, grilling, braising, stewing, etc.; avoid high-cholesterol foods such as fatty meat, internal organs, fish eggs, butter, etc. It is not advisable to eat spicy and刺激性 food, quit smoking and limit alcohol, avoid allergic foods: even after the suture is removed after surgery, dog meat, mutton, sparrow meat, sparrow eggs, bamboo shoots, scallions, pumpkin, beef, coriander, smoked fish, smoked meat, chili, chives, garlic sprouts, mussels, etc. should be avoided.

　　1. Western medical treatment methods for vulvar amebiasis

　　1. Metronidazole: the first choice, 0.4-0.6g/times for adults, 3 times/d, 50mg/(kg·d) for children, taken in three divided doses, for 10 days as one course.

　　2. Chloroquine: 0.5/times, 2 times/d, changed to 0.5g/d after 2 days, for a total of 2-3 weeks.

　　3. Quinacrine: 1.5-3g/d for adults, 42mg/kg for children, taken orally in three divided doses, for 10 days as one course.

　　4. Antibiotics: corresponding antibiotics can be used when there is a concurrent bacterial infection.

　　2. Local treatment

　　1. Wash the affected area daily, then apply metronidazole ointment externally. If there is a concurrent bacterial infection, an effective external disinfectant can be used for wet敷.

　　2. According to the condition of skin damage, perform surgical debridement, excision, skin grafting, or physical therapy such as electrocautery, microwave, laser, etc.

　　3. Eliminate the source of infection

　　The primary focus of treatment for amebiasis (such as amebic dysentery) is oral metronidazole; attention should be paid to dietary hygiene, boiling sterilization of underwear and socks; partners or sexual companions, cohabiting family members should undergo corresponding examinations and necessary treatment.