Fungal skin disease

Introduction to fungal skin diseases Fungal skin disease, also known as dermatophytosis, refers to a large class of infectious diseases caused by pathogenic fungi, human skin and skin appendages such as mucous membranes, hair and nails. It is a superficial fungal infection caused by dermatophytes invading the epidermis. Clinically, there are many vesicular scaly-type manifestations. The damage is mostly limited to one side. The initial blistering occurs, the number is different. The blister fluid is desiccated after drying, and the range is gradually enlarged. The skin of the desquamation is thick and thick, and the skin is wide and deep. Loss of normal luster, flexibility, and a sense of coarse sand. Because people's understanding of the dangers of cockroaches is not enough, they do not pay attention to it, and they often have their own development. In terms of ankles, most patients, the condition is not very serious, only itchy, so they never take the initiative to seek medical treatment; some patients are still not actively treated even if they have obvious symptoms, due to the long-term illness, become accustomed to Some patients, although cured after treatment, but because the source of infection is not controlled, and no preventive measures, they often relapse. The three kinds of people mentioned above are all carriers, which ultimately have the consequences: they may cause self-infection and attract others to happen; the society can spread to the surrounding people through various channels. basic knowledge The proportion of illness: 0.0025% Susceptible people: no specific population Mode of infection: contact spread Complications: skin cancer

Cause of fungal skin disease

Environmental factors (25%)

The place where the disease is transmitted is quite extensive, and the pathogens can be widely spread through public items such as slippers, tubs, foot basins, towels, hairdressing tools, and the like. It can be seen that the above public places must have strict management systems and disinfection measures, otherwise it is not easy to achieve control of their incidence.

Immunity factor (15%)

Although some people think that fungal infection is low, even if it is between the toes, if it is not broken, it is not easy to get sick. However, it is well known that people who do not pay attention to personal hygiene; patients with systemic diseases, such as diabetes, malignant tumors, etc.; long-term use of corticosteroids, immunosuppressants and antibiotics. The above situation will undoubtedly promote the occurrence of rickets.

Body transmission (45%)

Because people's understanding of the dangers of cockroaches is not enough, they do not pay attention to it, and they often have their own development. In terms of ankles, most patients, the condition is not very serious, only itchy, so they never take the initiative to seek medical treatment; some patients are still not actively treated even if they have obvious symptoms, due to the long-term illness, become accustomed to Some patients, although cured after treatment, but because the source of infection is not controlled, and no preventive measures, they often relapse. The three kinds of people mentioned above are all carriers, which ultimately have the consequences: they may cause self-infection and attract others to happen; the society can spread to the surrounding people through various channels.

pathology

Shallow fungal disease is a skin disease caused by pathogenic fungi that are parasitic to keratinous tissue. The pathogens can be divided into:

1. Dermatophytes: Parasitic skin keratin tissue pathogenic fungi are collectively referred to as dermatophytes. The bacterium is subdivided into the following three genera based on its invasive tissue differences and culture characteristics:

(1) Trichophyton: invades skin, hair and nails. The genus has been identified as having 13 species that can cause human disease. Commonly, there are Astragalus sinensis, Trichophyton rubrum, Trichophyton rubrum, Trichophyton rubrum, Gypsum-like Trichophyton, etc.; they are characterized by rod-shaped macromolecular spores with smooth walls.

(2) Sporozoites: Invading hair and skin. It is more common in China for rust-colored microspores and wool-like microspores; these cultures are fusiform macromolecular spores with thorns on the wall. Eight species have been reported to cause human disease.

(3) Epidermis: Invading the skin and nails. This genus is only a flocculent sputum bacterium, which can cause human disease, and its culture shows a scorpion-like or pear-shaped macromolecular spore. The above three genus dermatophytes can cause tissue reactions and cause erythema papules, blisters, scales, hair loss, hair loss and deck changes. According to the difference of its invasion site, the clinical can be divided into head lice, body lice, femoral hernia, hand, foot and sputum.

2. Aphis gossypii: A pathogenic fungus that is parasitic on the surface layer of the skin or the surface of the hair shaft can be described as a fungus. These sputum bacteria are divided into two types, namely the horn layer type and the hair type. The former has Trichophyton rubrum, Rhizoctonia solani, Mann's sputum and Wynn's sputum; the latter type has Trichophyton rubrum. Since the horn fungus is parasitic on the surface of human tissues, it generally does not cause an inflammatory reaction of the tissue, even if it is extremely slight.

Epidemiology

Shallow fungal diseases are widespread and spread throughout the world, and are also common in China. The incidence rate, according to several hospitals in Shanghai, this type of skin disease accounts for the second or third place in the total number of dermatology outpatients, and some even rank first; a force based on the 1985 Air Force Hospital investigation of the incidence of officers and soldiers on the front line of the Guigui Information: The hospital conducted a physical examination of 2,370 officers and soldiers of a group army. The results showed that there were 1,414 people suffering from superficial mycosis, accounting for 59.66% of the number of people inspected. In the first and second hospitals, the initial consultation fee for outpatient clinics from 1955 to 1964 was 40,731. Case statistics, 6108 cases of this type of disease accounted for 15.98%. The occurrence of superficial mycosis is related to the species type, individual resistance to bacteria and the environment. However, the prevalence of this type of skin disease is so widespread that the incidence is so high that the reasons may be related to the following factors:

1. The fungus is extremely viable: the bacterium does not contain chlorophyll, has no photosynthetic ability, and only survives by parasitism or saprophytic. The fungus prefers a moist and warm environment, and the optimum growth temperature is 25-26 ° C. It can grow at a pH of 3.0-10.0. Although it has weak resistance to high temperature (above 45 °C), it has strong adaptability to temperatures below 4 °C. It is also quite resistant to ultraviolet rays and radiation. It can be seen that the fungus does not require harsh living conditions. Therefore, people can detect pathogenic fungi from the atmosphere, on the body of animals and plants, human feces, on the floor and in the soil. In short, the fungus has strong living ability and is almost ubiquitous in nature, so the fungus The chances of infecting humans naturally increase.

2. Carriers are the main cause of the spread of superficial mycosis: because people do not know enough about the harm of cockroaches, they do not pay attention to it, and they often develop their diseases. In terms of ankles, most patients, the condition is not very serious, only itchy, so they never take the initiative to seek medical treatment; some patients are still not actively treated even if they have obvious symptoms, due to the long-term illness, become accustomed to Some patients, although cured after treatment, but because the source of infection is not controlled, and no preventive measures, they often relapse. The three kinds of people mentioned above are all carriers, which ultimately have the consequences: they may cause self-infection and attract others to happen; the society can spread to the surrounding people through various channels.

3. The spread of pathogenic fungi is so widespread that prevention is quite difficult: the place where the disease is transmitted is quite extensive, and the pathogens can be widely spread through public goods such as slippers, bath tubs, foot basins, towels, and hairdressing tools. It can be seen that the above public places must have strict management systems and disinfection measures, otherwise it is not easy to achieve control of their incidence.

Fourth, the body's own resistance to the disease also has a role to be ignored: although some people think that fungal infection is low, even in the toe, if the local is not broken, it is not easy to develop. However, it is well known that people who do not pay attention to personal hygiene; patients with systemic diseases, such as diabetes, malignant tumors, etc.; long-term use of corticosteroids, immunosuppressants and antibiotics. The above situation will undoubtedly promote the occurrence of rickets.

5. The external environment and the prevalence of cockroaches also have an important relationship: the fungus grows and breeds in a humid environment, so the disease occurs in the toes, and it is more common in hot and humid areas and hot summers.

It can be seen from the above description that superficial mycosis is contagious and can be transmitted by itself or by others. The infection mode of the disease: a direct contact infection, such as the incidence of head lice is often caused by direct contact with children suffering from head lice or rickets; second, indirect contact infection, such as frequent use of rickets patients Things like slippers, pillow covers, foot rubs, etc. can happen.

Fungal skin disease prevention

First, strive to do a good job in publicity and education, and popularize common knowledge and measures for prevention and treatment of rickets.

Second, actively heal patients with rickets, especially head lice and hand, foot and ankle, to fully mobilize the masses and carry out group defense.

Third, pay attention to personal hygiene, do not share daily life with patients.

Fungal skin disease complications Complications skin cancer

Mainly complicated by fungal infections.

Fungal skin disease symptoms Common symptoms Back acne benign reactivity changes extensive erythema infiltration... Fine mesh to patchy... Thigh long red

Common fungal skin diseases are:

First, tinea versicolor and Malassezia folliculitis: the two are the same kind of lipophilic yeast - different skin lesions caused by Fusarium oxysporum. It is also known as a sweat spot, which is characterized by finely chipped patches with pigmentation and pigmentation. Malassezia folliculitis, also known as pityrosporum folliculitis, is characterized by acne-like papules. It can be parasitic in normal human skin, but it is prone to morbidity in patients with hyperhidrosis, fat, bathing, changing underwear, chronic diseases, malnutrition, or patients receiving corticosteroids or chronic infection. The subtropical region is more common, mainly for adolescents, and 16-40 years old is a high-risk age. The upper part of the human hair is rich in sebaceous glands, which is a good site for the disease.

Second, dermatophytosis

1. Head lice: Head lice are skin dermatophytes of the scalp hair follicles, which usually cause inflammatory or non-inflammatory hair loss, mainly in prepubertal children. There are three types of head lice under the microscope: hair shape, hair type and jaundice. Clinical manifestations of hair loss and scaly often accompanied by inflammatory reactions.

2, body sputum: body sputum and femoral hernia refers to the smooth skin epidermis dermatophyte infection, femoral hernia refers to the body sputum occurring in the groin, perineum, perianal and buttocks. At the beginning of the disease, the skin is red, and the needle is large or the size of the rice is red rash, small water sore, but the edge is clear. As the disease progresses, the skin lesion gradually expands outward, and the center part heals, and the expanded edge shows obvious water. Sore, herpes, and concentric circles, the area can be large or small, consciously itching. The incidence rate is affected by many factors such as climatic conditions, patient occupation or living habits, health status, and body resistance.

3, hand and foot sputum: hand sputum and athlete's foot refers to the dermatophyte infection that occurs in the skin of the hands and feet and except the back of the skin. Especially in the foot, the prevalence rate is as high as 30%-70%. Susceptible factors are hot and humid climate, excessive sweating and fat in the foot, partial under-breathing, and diabetes. Hand, foot and ankle are divided into three types: scaly keratinization, blistering, and rubbing. Squamous keratosis is mainly characterized by hyperkeratosis, rough and sweatless, dry, scaly, keratinized and ruptured, which can cause pain. The blister type appears as a deep blister that is scattered or clustered, occurring between the palm of the hand or the finger (toe), and the symptoms are severe itching. Blisters can be secondary to infection, causing lymphadenitis and the like. The rubbing type is often mixed with the blister type, and the toe skin is impregnated and whitened, often because the impregnated epidermis is removed, the rosy wet surface is exposed, and the bacterial infection is easily caused by lymphangiitis, erysipelas, cellulitis, etc. .

4. Hyperthyroidism and onychomycosis: is a fungal infection of the deck and underarm tissue caused by pathogenic fungi. Fungi are often derived from the hand and foot, and the fungus that invades the nail is mainly red fungus. Most of the invading nails are epidermal bacteria, and a few are Candida albicans and red fungi. For a common disease, frequently-occurring disease. The older you are, the more susceptible you are. Obesity and diabetes, HIV infection, abuse of antibiotics, and impaired renal function are prone to this disease.

3. Coloring germination or coloring fungal disease: a group of chronic focal infections of the skin and subcutaneous tissue caused by a variety of brown (dark) fungi. The most common part is the extremities, characterized by progressively increasing sputum. Proliferative and crusting damage. Common in outdoor activities and barefoot.

4. Sporotrichosis: sporotrichosis is a subacute or chronic infection caused by the biphasic fungus S. serrata. It usually manifests as lymphatic spread, which can cause infections in the lungs, joints, bones or other parts. It is common in temperate and tropical regions, and adults are more common than children, especially in occupational individuals who are often exposed to soil, plants or plant matter.

5. Dark filamentous mildew: Dark filamentous mildew refers to subcutaneous and deep tissue infections caused by a variety of pathogenic brown (dark) fungi. Such fungi are distinguished from pathogenic bacteria of the skin coloring fungal disease, which are characterized by pigmentation in the walls of fungal cells in which hyphae cultures or in most cases of tissue are formed in tissues.

6. Skin and mucosal candidiasis: Candidiasis refers to infections caused by Candida. Candida can be isolated from the oral cavity and digestive tract of 30-50% of normal people. The prevalence of Candida in the reproductive tract of normal women is also as high as 20%. Candida is one of the normal flora of the human body. It is a pathogenic bacteria that can easily cause infections of mucous membranes, skin and nails. Common vaginal candidiasis, candida glans dermatitis, cutaneous candidiasis, candida infection 5 kinds of chronic mucosal cutaneous candidiasis.

Examination of fungal skin diseases

According to the medical history and clinical manifestations, the diagnosis is generally easier. If necessary, the following auxiliary checks can be performed:

First, fungal microscopy : select the scales on the edge of the lesion or a few lesions. Place on a glass slide, add a drop of potassium hydroxide solution, and cover the slide. It is then placed on an alcohol lamp for a while to promote keratin dissolution. Finally, a microscopic examination was performed. A positive fungal test has a definitive diagnosis for the diagnosis. If it is negative, the diagnosis of sputum cannot be ruled out.

2. Fungal culture: The conventional medium is a sabourauad medium. Inoculate the scales, hair or blisters taken from the lesions and place them in an incubator at 25~30 °C. Generally, colony growth can be seen in about 5 days, and then the strain can be identified. If the culture is aseptically grown for three weeks, the culture can be reported to be negative.

Third, filtered UV lamp inspection: This lamp is also known as Wood (wood) lamp, the ultraviolet light through the glass device containing nickel oxide, in the dark room, some fungi can be seen, the color of the fluorescent light is filtered under the ultraviolet light. . This can provide an important reference for the diagnosis of superficial mycosis, especially head lice, according to the presence or absence of fluorescence and color. In addition, the lamp is also helpful for group inspections such as nurseries.

Diagnosis and identification of fungal skin diseases

diagnosis

According to the medical history and clinical manifestations, the diagnosis is generally easier. If necessary, the following auxiliary checks can be performed:

First, fungal microscopy: select the scales on the edge of the lesion or a few lesions. Place on a glass slide, add a drop of potassium hydroxide solution, and cover the slide. It is then placed on an alcohol lamp for a while to promote keratin dissolution. Finally, a microscopic examination was performed. A positive fungal test has a definitive diagnosis for the diagnosis. If it is negative, the diagnosis of sputum cannot be ruled out.

2. Fungal culture: The conventional medium is a sabourauad medium. Inoculate the scales, hair or blisters taken from the lesions and place them in an incubator at 25~30 °C. Generally, colony growth can be seen in about 5 days, and then the strain can be identified. If the culture is aseptically grown for three weeks, the culture can be reported to be negative.

Third, filtered UV lamp inspection: This lamp is also known as Wood (wood) lamp, the ultraviolet light through the glass device containing nickel oxide, in the dark room, some fungi can be seen, the color of the fluorescent light is filtered under the ultraviolet light. . This can provide an important reference for the diagnosis of superficial mycosis, especially head lice, according to the presence or absence of fluorescence and color. In addition, the lamp is also helpful for group inspections such as nurseries.

Identification

First, head lice should be differentiated from psoriasis, seborrheic dermatitis and alopecia areata: Psoriasis is more common in adults and less from childhood. In addition to the lesions in the head, it is often involved in the trunk and extremities. The lesions were plaques with thick silvery white scales on the surface. The hair at the lesion is brush-like, but there is no pathological change in itself, that is, no hair loss, hair loss, dryness, dry bending, etc.; seborrheic dermatitis is mostly in adults, which occurs in the eyebrows, nasolabial folds, Beard, armpit, central torso and haze. The rash is erythema, papules, and oily scales on the surface. Unbroken elephants, itchy; alopecia areata, commonly known as "ghost shaving." There were many mental disorders before the onset, and the lesions showed a kind of alopecia-like hair loss. The boundary was clear, and there was no inflammatory reaction or scale in the hair loss area. Subjective without itching. The above-mentioned dermatological hair fungal examinations were all negative.

Second, the body must be identified with pityriasis rosea and psoriasis: pityriasis rosea occurs in the trunk and proximal extremities, the rash is widespread and symmetrically distributed, mainly as erythema, the long axis of the lesion and the dermatoglyph or rib Balanced, surface with scaly scales. Fungal microscopy is negative; psoriasis is more common in winter and relieves in summer. The remainder of the identification content refers to the above.

Third, the femoral hernia should be mainly differentiated from neurodermatitis and chronic eczema: the neurological rash and the chronic eczema fungal examination are negative, the two diseases have no damage edge slightly higher than the adjacent normal skin, and there is no summer heavy winter light phenomenon .

Fourth, the hand and foot should be identified with eczema and sweat herpes: eczema often involves the back of the hands and feet and the toe extension, often symmetrically distributed. Acute rash is pleomorphic damage. Chronic people often see infiltration, can be moss-like, dark red color, the boundaries are generally clear; sweat herpes occurs on the side of the finger and the edge of the palm, often accompanied by hyperhidrosis. The above diseases were all negative for fungal examination.

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