systemic candidiasis
Introduction
Introduction to systemic candidiasis Systemic candidiasis is an invasive infection caused by Candida species dominated by Candida albicans. It manifests as fungalemia, endocarditis, meningitis and focal lesions of the liver, spleen, kidney, bone, skin and subcutaneous tissue or other tissues. Candida is present in the oral cavity, intestines, and vaginal mucosa of normal people but does not occur. When certain physical causes cause the pH value in the vagina to decrease, and the acidity increases, Candida will be extensively complicated. basic knowledge The proportion of illness: 3%-6% Susceptible people: no specific population Mode of infection: respiratory, sexual, and digestive tract Complications: enteritis gastrointestinal dysfunction
Cause
Causes of systemic candidiasis
Infection factor (25%):
Candidiasis is caused by endogenous pathogens and is generally not obtained from the surrounding environment. Candida is present in the oral cavity, intestines, and vaginal mucosa of normal people but does not occur. When certain physical causes cause the pH value in the vagina to decrease, and the acidity increases, Candida will be extensively complicated. Infections caused by Candida account for 80% of all major systemic fungal diseases. Today, Candida has become the fourth most common pathogen of bloodstream infections and is the most common pathogen of fungal infections in immunocompromised patients.
Infections are usually associated with multiple injuries or surgery. Multi-course broad-spectrum antibiotic therapy and/or intravenous supplementation with high nutrition. The injected venous access and gastrointestinal tract are the usual invasive portals for Candida. The occurrence of endocarditis may be related to the abuse of intravenous drugs, heart valve replacement and intravascular injury. Fungalemia can lead to meningitis and focal lesions of the skin, subcutaneous tissue, bone, joints, liver, spleen, kidney, eyes and other tissues. In addition, myeloperoxidase deficiency, decreased transferrin and elevated serum iron, zinc ion deficiency, hyperglycemia, vitamin A deficiency and skin damage can induce candidiasis. Broad-spectrum antibiotics, adrenocortical hormones (hormones), immunosuppressive agents, radiotherapy and chemotherapy; catheters, infusions (especially parenteral high-nutrition therapy), surgery (especially gastrointestinal and prosthetic valve surgery), burns, etc. Can reduce the body's defense function, or create conditions for the invasion of bacteria to increase the chance of infection.
Susceptible population (25%):
In immunosuppressed patients, Candida albicans and Candida tropicalis are the most common.
Patients with impaired T-cell-mediated immune defense mechanisms caused by AIDS patients, or other causes, can occasionally occur in other patients.
In women with normal immunity, vaginal candidiasis often affects women.
After the use of antibiotics, patients with neutropenic anti-cancer chemotherapy and non-neutropenic patients.
Pathogen infection (15%):
The spore wall of Candida albicans is mainly composed of glycogen and mannan, and the latter can enhance the adhesion ability of Candida albicans and cause infection. Experiments have shown that Candida albicans with germ tube is stronger than pure spores. Secondly, Candida albicans is often mycelium in tissues, and is less susceptible to phagocytosis than spores. Therefore, its pathogenicity is increased, and other Candida strains have weak mycelium formation, so the pathogenicity is also weak. In addition, Candida may also produce high molecular weight and low molecular weight toxins and some hydrolases, which damage the body tissues and induce infection.
Prevention
Systemic candidiasis prevention
Prevention of infection in pregnant women and infants: avoid cross-conception in the delivery room. Always wash the baby's mouth with warm water, breastfeeding equipment is boiled and disinfected, and should be kept dry. Before the breastfeeding, the maternal nipple is best washed with 1/5000 hydrochloric acid chlorhexidine solution, and then wiped with cold water.
Prevention of infection in children: Children should protect their lips from dryness and cracking in winter, and correct bad habits of licking lips and tongues.
Complication
Systemic candidiasis complications Complications enteritis gastrointestinal dysfunction
Lesions affect the digestive tract, mainly manifested as esophagitis, enteritis, involving the urinary system, mainly manifested as frequent urination, urgency, urine turbidity, flocculation; involving the mucosa, mainly for respiratory infections, oral infections, also Endocarditis and meningoencephalitis occur.
Involvement of the reproductive system, can be complicated by female infertility: suffering from candida vaginitis, changes in the pH of the vagina will inhibit sperm motility, and inflammatory cells can swallow sperm and weaken sperm motility, white rosary The bacteria have the effect of agglutinating sperm, as well as sexual pain and loss of libido at the time of inflammation, which can affect pregnancy. It can also cause inflammation of the male foreskin glans.
Symptom
Symptoms of systemic candidiasis common symptoms dysuria urinary urgency urgency fever heart sputum dizziness
Different parts of the infection cause different symptoms, which can invade the skin and mucous membranes, and can affect the internal organs.
Pancreatic candidiasis
Its performance is extensive erythema and scaly damage, the boundaries are more distinct, and there are often scattered papules or blisters around. Often accompanied by thrush or gastroenteritis.
Mucosal candidiasis
The most common symptom of esophageal infection is dysphagia. Symptoms of respiratory infections are non-specific, such as coughing, vaginal infections can cause itching, burning sensation and vaginal discharge. Occasionally in the oral mucosa, tongue, throat, gums and lips, mouth and mouth, the skin lesions are scattered in different sizes of milky white film, its shape is like the name of the goose. The film is easily smeared and has a wet red moist surface. In addition, Candida can also cause esophagitis, endocarditis, meningitis.
Visceral candidiasis
Patients with candidal enteritis exhibit abdominal discomfort, hyperintestinal hyperactivity, chronic diarrhea and anal itching. Candida bronchitis, the main symptoms are coughing and coughing out of mucous glia. Candida uritis, pathogenic bacteria retrograde infection from the urethra and cause urethritis, cystitis and pyelonephritis. The patient has symptoms such as urgency, frequent urination, dysuria, difficulty urinating or hematuria. It can also invade other internal organs such as liver and spleen.
Candidaemia
It often causes fever, while other symptoms are generally non-specific. Sometimes, a syndrome similar to bacterial sepsis can occur, and the course of the disease is fulminant, with shock, oliguria, renal failure, and disseminated intravascular coagulation. Blood-borne endophthalmitis begins with white retinal turbidity, and as the destructive inflammation progresses, the vitreous can be turbid, eventually resulting in irreversible scarring leading to blindness. Eye involvement in patients with neutropenia often manifests as retinal hemorrhage.
Examine
Examination of systemic candidiasis
Laboratory inspection
Scales at the skin lesions, membranes in the oral mucosa, sputum, urine, blood, cerebrospinal fluid, pleural effusion, ascites, and various tissues.
Direct microscopic examination of fungi
Direct microscopic examination of specimens found a large number of hyphae and group of spores have diagnostic significance. For example, only spores, especially in sputum or vaginal secretions, may be normal carriers. No clinical significance. The presence of hyphae indicates that Candida is in a pathogenic state. Shabu's agar culture is yeast-like growth, transplanted rice flour Tween agar, 25 ° C, 24 hours; or serum, 37 ° C for 3 hours, if there is a apical thick-walled spore or germ tube formation, identified as Candida albicans. Other Candida species must be identified by fermentation and assimilation tests. Pathological examination can identify Candida, but the species cannot be identified.
Fungal culture
The specimens were inoculated into Saar's agar at 37 ° C or room temperature, and the colonies with moist, milky white and yeasty smell were grown for 2 to 4 days. Serum germ tube test or 1% rice flour Tween 80 medium was found on the top of the thick-walled spores as the basis for the identification of Candida albicans.
Immunological diagnosis
Patients with deep candidiasis have low cellular immune function, lack of leukocyte migration inhibitory factor (LIF), and white blood cell movement inhibition index (MI) > 0.8. When the disease is still or getting better, the LIF returns to normal, MI < 0.8. Therefore, the determination of LIF can be used as an indicator for disease diagnosis, prognosis and efficacy assessment. The candida skin test has reference value for the diagnosis of candida rash.
Gas chromatography
The concentration of serum mannose is measured to diagnose deep candidiasis. In patients with disseminated candidiasis (including candida sepsis), serum mannose concentrations are greater than 800 g/ml, non-dispersive patients can be between 600 and 800 g/ml, and normal and non-candida infections are lower. 600 g/ml. This method is highly specific, accurate and accurate, and the sample is used in a small amount (only 0.2ml each time).
Diagnosis
Diagnosis and identification of systemic candidiasis
diagnosis
Diagnostic criteria:
According to different organs and stage of onset, histopathological changes may be inflammatory (such as skin, lung), purulent (such as kidney, lung, brain) or granulomatous (such as skin). Special organs and tissues can also have special manifestations. For example, the esophagus and small intestine may have ulcer formation, and the heart valve may show proliferative changes. In acute disseminated cases, microabscesses often form, and spores and hyphae are seen in the abscess. There are neutrophil and tissue cell infiltration. Occasionally, the eosin-like substance is similar to the stellate. Hyphae sometimes invade the blood vessel wall, and mycelium is found to have diagnostic value in pathological tissues.
(1) bronchial and pulmonary infections cough, cough, fever; (2) digestive tract infection esophagitis, enteritis; (3) urinary tract infection urethral intubation and blood line dissemination more common; (4) sepsis; (5) Endocarditis; (6) meningoencephalitis; (7) ocular retinitis, choroiditis; (8) allergic rash.
Diagnosis must have characteristic clinical lesions, histopathological evidence of the affected tissue, or exclusion of other causes. Positive culture of blood, cerebrospinal fluid, pericardial or pericardial effusion, or biopsy tissue specimens is the basis for determining the need for systemic treatment. Tissue histopathological signs caused by yeast, pseudohyphae and/or hyphae are also of diagnostic value in tissue specimens. But often it is speculative to start treatment. Although various serological methods for detecting antibodies or antigens have been carried out, none of them have sufficient specificity and sensitivity for rapid diagnosis or exclusion diagnosis of severe patients.
Clinical manifestations can not be explained by other diseases, and there are predisposing factors and positive bacteria (refer to conventional fungal examinations), the possibility of candidiasis should be considered, and further examination.
Differential diagnosis
Clinically, it should be differentiated from the primary disease first; it should be differentiated from aspergillosis in histopathology and be identified with other yeasts in mycology. Candidiasis can be similar to many diseases of the skin, mucous membranes or internal organs, and the final diagnosis depends on the combination of fungal examination and clinical. Because Candida belongs to the normal flora of the human body, the specimen can not be diagnosed as candidiasis by simple culture, and it must cooperate with direct examination and clinical manifestation. Fungal examinations include direct examination and culture, and should be positive and the same species. Direct inspection should see hyphae and clusters of spores. Hyphae indicates that Candida is in a pathogenic state. Positive culture can only indicate the species, and it cannot indicate whether it is pathogenic.
1, genital white candidiasis is often confused with genital trichomoniasis. The common symptoms are genital itching, increased secretions and leucorrhea, but the former genital secretions are cheese-like or bean dregs, and the latter's genital secretions are grayish yellow with a stench. Direct microscopic examination helps differential diagnosis between the two.
2, oral mucosal candidiasis should be identified with oral mucosal plaque, lichen planus, secondary syphilis:
(1) Oral lichen planus: damage is common in the posterior side of the buccal mucosa, the ventral side of the tongue, the back of the tongue, the gums, the ankle and the throat. The lesions are dendritic or reticular silvery white lines and small papules, symmetrically distributed, lip The department may have mild erosion, exudation, and obvious adhesive shoulders. The direct microscopic examination of the fungus was negative.
(2) leukoplakia: more common in middle-aged men, mainly in the cheeks, lips, tongue mucosa, hard palate, gums and so on. Skin lesions are white patches, single or multiple, with unclear boundaries, slightly raised edges, and no symptoms. Histopathology is epithelial dysplasia, and fungal direct microscopy is negative.
(3) secondary syphilis: about 1/3 of the second-stage syphilis may have mucosal plaques, which occur in the inner side of the lips and cheeks, tongue, pharynx, tonsils, and throat. Mainly manifested as mucosal redness, erosion, overlying grayish white exudate, a dark red halo on the edge, no symptoms. The mucosal plaque contains a large amount of toxoplasma.
3, Candida cheilitis should be identified with light linear cheilitis. Candida keratitis should be differentiated from vitamin B: deficiency and bacterial angular keratitis.
4, Candida impetigo should be identified with bacterial impetigo.
5, urinary system candidiasis should be differentiated from urethritis, cystitis and pyelonephritis caused by other pathogen infections.
6, Candida infection of the skin should be identified with eczema, seborrheic dermatitis. Direct microscopic examination of the lesion site can be confirmed by seeing pseudohyphae.
