The most common pathogenic factors in skin diseases are infectious diseases and allergic dermatitis. However, with the degradation of age, senile skin diseases and skin cancers are also important skin diseases. In addition, we should pay attention to all kinds of skin diseases with side effects caused by drug treatment. Specifically, it can be summarized into the following categories:
1. Physical and chemical factors
Pressure and friction, excessive local temperature change, radiation, light, thermal radiation, chemical reagents and other factors will cause skin diseases. Some factors can aggravate skin diseases. Such as excessive scratching secondary infection; Hot water scald, soap washing and improper medication aggravate eczema skin lesions; Exposure will aggravate photosensitive diseases.
2. Biological factors
Insect bites, contact with certain plants, parasites and microbial infections are all common pathogenic factors, such as various viral skin diseases caused by viral infections.
3. Food and other diseases
Some foods, such as shrimp, are prone to allergic diseases. Visceral diseases, local infections, blood and lymph circulation disorders can cause related skin diseases, such as diabetes patients are prone to itching, local infections cause infectious eczema-like dermatitis, and circulatory disorders can cause cyanosis and rubber swelling.
4. heredity
Some diseases have obvious family history, such as ichthyosis and albinism.
5. Neuropsychological factors
Nerve injury can cause nutritional ulcer; Stress is closely related to stress, alopecia areata and chronic lichen simplex.
6. Metabolic and endocrine factors
Metabolic disorders can lead to skin amyloidosis and xanthoma, while Cushing syndrome is prone to acne and hirsutism.
diagnose
The diagnosis of dermatosis, like other diseases, must be comprehensively analyzed according to the medical history, physical examination and laboratory examination:
1. Ask for medical history
Dermatology should focus on asking patients whether they have self-conscious symptoms, duration and degree, prone parts of skin lesions, occurrence sequence, distribution, shape, color, whether they have other diseases or drugs before onset, whether they have systemic symptoms, and whether they are related to seasons, climate, living and working environment, diet, etc. Whether there is a similar skin disease in the family, the diagnosis and treatment after the onset and the curative effect.
2. Physical examination
(1) Focus on checking whether the distribution position, type, quantity, size, shape, surface and base, color, blister contents and their colors, arrangement characteristics and boundaries are clear.
(2) Auxiliary physical examination
1) Press the glass slide 10 ~ 20 seconds hard at the injured area, and the color of the inflammatory erythema and hemangioma will disappear. It can be used to distinguish erythema from purple spots and observe lupus nodules.
2) Dermatoglyphics: Scratching the skin with a blunt object, such as wheal at the scratching place, is called dermatoglyphics positive. Patients with urticaria are often positive, and the skin of atopic dermatitis and erythroderma is mechanically stimulated, and the skin appears pale anemia reaction.
3) Sensory examination includes temperature, touch and pain.
4) The filtered ultraviolet rays show dark green fluorescence in hysterical hair and bright green fluorescence in tinea versicolor. Other diseases, such as tinea versicolor and porphyria, can emit different colors of fluorescence.
5) Echinolysis sign (Nissl's sign) is positive when the blister spreads around, the normal skin is pushed away, and the skin with normal appearance between blisters is wiped off.
3. Laboratory inspection
(1) Histopathological examination of skin Some skin diseases have unique pathological changes, which can be used for diagnosis and differential diagnosis.
(2) Skin test ① Patch test is used to check contact allergens. ② Scratch test or intradermal test is used to check the immediate allergic reaction and determine whether the substance has allergic reaction (type I). ③ Leprosy test is used to judge the immunity of leprosy patients. ④ Trichophyton test is helpful for the diagnosis of tinea rash.
(3) Microbiological examination of dermatophytes and leprosy scabies is helpful for the diagnosis of corresponding skin diseases.
treat cordially
Topical drugs are the most commonly used drugs to treat skin diseases. If the external drugs are improperly selected or used, they are often ineffective and even aggravate the condition.
The following aspects should be paid attention to in the selection of topical drugs for dermatoses: the same drug has different dosage forms, such as solution, ointment, powder, cream, lotion, ointment, tincture, emulsion and so on. Different dosage forms have different functions and indications, and different external dosage forms should be selected according to the clinical symptoms and skin lesions at different stages.
1. Generally, when local redness, blisters and erosion occur in the acute phase, wet compress with solution is often used, which can play the role of anti-inflammation and heat dissipation; If there is exudation, wet compress with solution first, and then use oil.
2. When the skin lesions are in subacute stage, the redness and swelling are reduced, and the exudation is reduced. Paste, powder and lotion can be selected as appropriate to play the role of anti-inflammation, itching relief, convergence and protection.
3. Cream, ointment, plaster, etc. It can be used for chronic skin lesions thickening and lichenoid transformation.
4. Pay attention to the time and frequency of skin disease medication. Liquid medicine and lotion are volatile, which reduces the curative effect, and the number of drug use is more, generally 3 hours 1 time; Tincture and ointment have a lasting effect, and each time is/kloc-0 in the morning and evening. Wet compress method should also be appropriate. Before taking the medicine, in addition to cleaning the affected area, the scab skin should be disinfected and softened with cooking oil and then wiped off. If you see a blister with a diameter greater than half a centimeter at the lesion, take out the contents with a sterile empty syringe and keep the blister wall. Shave your hair before applying the medicine to the part with hair, and then apply the medicine.
5. Age, sex, affected area and patient's constitution should also be considered when choosing drugs. For example, patients of all ages should choose low-concentration drugs; When pregnant women use external drugs, they should consider the impact on the fetus and baby; Do not use drugs with high concentration or strong irritation on face, breast and vulva, and children and women should use them with caution; High concentration drugs can be used on palms and soles; For skin sensitive person, first use low concentration, then use high concentration. For new drugs or allergic drugs, first use them in a small area, and if there is no response, then gradually increase the concentration as needed to expand the use area.
Physical therapy is also a common treatment for skin diseases. Commonly used physical therapy includes electrotherapy, phototherapy, microwave therapy, cryotherapy, laser, hydrotherapy and radiotherapy.
Dermatology belongs to surgery and mainly treats various skin diseases. The common skin disease is psoriasis.
, herpes, rosacea, pustulosis, suppurative infection, scar, tinea, ichthyosis, bromhidrosis, acne, folliculitis, alopecia areata, andropathy, diaper rash, corns, freckles, herpes zoster, acaroid dermatitis, vitiligo, eczema.
, onychomycosis, scleroderma, skin itching, oral care, hair removal, chloasma, etc.
Epidermis is the outermost layer of skin, with an average thickness of 0.2 mm. According to the different development stages and morphological characteristics of cells, it can be divided into five layers from outside to inside.
The stratum corneum consists of several layers of keratinocytes and contains keratin. It can resist friction and prevent body fluids from leaking out and chemicals from invading. Keratin has strong water absorption, and the water content is generally not lower than 10% to maintain the softness of skin. If it is lower than this value, the skin will be dry and scaly or chapped. Due to different parts, its thickness varies greatly, such as eyelids, foreskin, forehead, abdomen, elbow fossa and other parts are thinner, and palms and soles are the thickest. Cells in the stratum corneum have no nuclei, and if there are nuclei left, it is called dyskeratosis.
2. Toumian
It consists of 2-3 layers of flat transparent cells, the nucleus disappears and contains keratin. It can prevent the penetration of water, electrolyte and chemicals, so it is also called barrier zone. This layer is most obvious in the palm and metatarsal bones.
3. Granular layer
It consists of 2-4 layers of flat spindle cells and contains a large number of basophilic transparent keratinocytes. When spindle cells in granular layer increase, it is called granular layer hypertrophy, which is often accompanied by hyperkeratosis; The granular layer disappears, often accompanied by poor keratinization.
2. Spinal cell layer
It consists of 4-8 layers of polygonal spinous cells, which gradually flatten from bottom to top, and the cells are connected with each other through desmosomes, forming a so-called intercellular bridge.
⒌ Basal layer: It consists of a layer of columnar cells arranged in a grid. The cells in this layer divide constantly (3%~5% cells often divide), and gradually move upward, and keratinize and deform to form other layers of the epidermis, and finally keratinize and fall off. The time from basal cell division to shedding is generally considered as 28 days, which is called replacement time, in which the time from basal cell division to top layer of granular layer is 14 days, and the time from stratum corneum formation to final shedding is 14 days. There is a kind of melanocyte (also called dendritic cell) from neural crest between basal cells, accounting for 4%~ 10% of the whole basal cells, which can produce melanin (pigment particles) and determine the depth of skin color.
corium
Derived from mesodermal leaves, it consists of fibers, matrix and cells. The dermal papilla close to the epidermis is called papillary layer, also known as superficial dermis; It is called reticular layer, also called deep dermis, and there is no strict boundary between the two.
1. fiber: collagen fiber, elastic fiber and reticular fiber.
⑴. Collagen fiber: It is the main component of dermis, accounting for about 95%, and assembled into bundles. In the papillary layer, the fiber bundles are thin, closely arranged, with different trends and no interweaving. In the reticular layer, fiber bundles are thick, loosely arranged and interwoven into a net, and many of them are parallel to the skin surface. Because the fiber bundle is spiral, it has certain flexibility.
⑵. Elastic fiber: There are many reticular layers at the lower part, which are mostly coiled under the collagen fiber bundles and around the skin accessory organs. In addition to giving skin elasticity, it also constitutes a scaffold for skin and its appendages.
⑶. Reticular fiber: It is considered as immature collagen fiber, which wraps skin appendages and blood vessels.
Matrix: It is an amorphous and uniform colloidal substance, which is filled between fiber bundles and cells, providing material support for various skin components and providing a place for substance metabolism.
3. Cells: There are mainly the following types:
⑴. Fibroblast: It can produce collagen fiber, elastic fiber and matrix.
⑵. Histocyte: It is an integral part of reticuloendothelial system, which has the ability to devour microorganisms, metabolites, pigment particles and foreign bodies, and plays an effective role in removing them.
⑶. Mast cells exist in dermis and subcutaneous tissue, especially in dermal papillary layer. The granules in its cytoplasm can store and release histamine and heparin.
corium
Derived from mesodermal leaves, in the lower dermis, it consists of loose connective tissue and fat lobules, close to the muscle membrane. The thickness of subcutaneous tissue varies with age, sex, location and nutritional status. It has the functions of preventing heat dissipation, storing energy and resisting external mechanical impact.
The manifestations of acute eczema
It is a kind of primary polymorphous rash, which often appears needle-to-millet-sized papules and papules on the basis of erythema, and in severe cases, small blisters often merge into pieces. The boundaries are unclear. At the periphery of the lesion, the polymorphic rash gradually becomes sparse and itchy, and often forms a punctate surface due to scratching, with obvious serous exudation. If accompanied by secondary infection, pustules, pus and pus scabs can be formed, and the corresponding lymph nodes can be swollen.
The distribution of acute eczema is often symmetrical, which is more common in exposed parts such as face, ears, hands, feet, forearms and calves, and can expand the whole body in severe cases.
Self-conscious symptoms include severe itching and burning sensation, which can suddenly worsen, especially at night.
(ii) Subacute eczema
After acute attack, swelling and exudation are reduced. In subacute stage, it can be characterized by papules and a small amount of papules, which are dark red with scales and slight infiltration. Some of them may have an acute attack due to re-exposure to allergens, improper handling of new stimuli or excessive scratching, or they may be light and heavy, and may develop into chronic eczema after a long time.
(C) Chronic eczema often
Delayed from acute phase and subacute phase, or inflammation is not very serious at the beginning, with papules, scratches and scales on dark erythema, thick skin, rough surface, lichenoid transformation, pigmentation or part of hypopigmentation area, etc. , and the illness lasts for several months or more.
Chronic eczema usually occurs in the hands, feet, calves, cubitus fossa, thighs, breasts, vulva, anus and other parts, and its manifestations are different due to different lesion sites.
Hand eczema has a high incidence rate because of its exposure to various external stimuli, and most of them have a slow onset. Dark red spots appear on the back of the hand and fingers, with obvious infiltration and hypertrophy, clear edges, dry and rough surface, and the diameter can be from 1-2cm to several centimeters or more. Cracks often appear in winter, and similar injuries are often found in feet and ankles.
Breast eczema is more common in lactating women, with dark erythema, papules, papules under nipples, areola and breasts, unclear boundaries, erosion, exudation, cracking, obvious itching, unilateral or symmetrical, and easy to recover after stopping breastfeeding.
Eczema of vulva, scrotum and anus, severe itching, often caused by excessive scratching and scalding with hot water, is red, swollen, exudative and erosive, and chronic cases are lichen-like.
Eczema of the leg, especially chronic eczema located in the lower part of the inner leg, is often secondary to varicose veins of the leg. At first, it is a dark erythema with unclear boundary, and then there are small papules and papules, which are easy to seep out and produce erosion and ulcers. Over time, the skin is obviously thickened, hardened and pigmented.
In addition, there are some feature types, such as:
1. Coin eczema
The lesion is a round or quasi-round coin-shaped plaque, which consists of compact small papules and papules with clear boundaries and a diameter of 1-3cm. In the acute stage, the lesions exude in a flush state, and there may be scattered papules around them. After the chronic stage, the skin lesions become thicker, the pigment increases, the surface is covered with dry scales, and the limbs are easy to itch.
2. Infectious eczema-like dermatitis (infectious
Eczematous dermatitis)
The common diseases are ulcer, sinus, chronic suppurative otitis media, skin around abdominal fistula, etc., which are related to mixed factors such as infected secretions and bacterial toxins, or the stimulation of improper external treatment and contact allergy. At first, the original skin damages the surrounding skin, and the itching is aggravated, and then scattered red papules and blisters appear, which can cause erosion and local lymph nodes can be swollen and tender. Parallel erythema, papules and water marks scratched by inoculation can be seen far and near the injury. If we can clean the wound, eliminate chemical stimulation and control infection, the condition can be improved quickly. If secretions continue to be produced, the rash will often be light and heavy, and will not subside until the original injury improves.
3. Stagnant dermatitis (stagnation
Dermatitis)
It is one of the common skin manifestations of varicose vein syndrome. It is induced by slow blood return, venous congestion, decreased blood oxygen content and nutrients, and increased capillary wall permeability after varicose veins. The clinical manifestations are mild edema of lower leg13, dark brown pigmentation and punctate red spots near the front of tibia and ankle, followed by eczema such as papules, papules, exudation, erosion and scabbing, and chronic eczema is dry and hypertrophy.
4. Cracked eczema (eczema
craqude)
Also known as seborrheic eczema (eczema)
Eczema) This is a kind of dermatitis caused by dehydration and dryness of the skin due to long-term exposure to warm and dry environment or frequent scalding by hot water. Its clinical manifestations are erythema, dry scales, tiny cracks in epidermis or cuticle, and linear red spots are exposed at the cracks, which are like broken porcelain pieces. They can occur in a certain part of the body, but mostly in front of the lower limbs, especially in winter and in the elderly.
5. Infantile eczema (eczema
Eczema)
Known as "milk tinea" in traditional Chinese medicine, it is an acute or subacute eczema that occurs on the baby's head and face. There are mild erythema and small papules on the cheeks and forehead, which are clustered or scattered. Severe cases can develop into erythema, papules, papules and herpes, with obvious exudation and scratches. Most of them are small rotten faces with thick scabs on the surface, which can invade the whole face and extend to the head and neck. Some people call this disease infantile hereditary allergic dermatitis.
In acute eczema, there may be sponges and blisters on the epidermis, capillaries in the superficial dermis are dilated, and lymphocytes and a small number of neutrophils and eosinophils can be seen around. In the chronic stage, the epidermal spinous layer is obviously thickened, accompanied by hyperkeratosis and dyskeratosis, the capillary wall of the superficial dermis is thickened, and the collagen fiber can be slightly thickened.
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Dietary health care
Diet should be light, eat more fruits, vegetables, beans and high-cellulose foods, and avoid allergic and irritating foods such as fish, shrimp, peppers, strong tea, coffee and wine.
Preventive nursing
Patients with eczema should avoid drinking alcohol, coffee, spicy and fried food, have a light diet, eat more fruits and vegetables, and eat less hot fruits such as durian, mango, longan and litchi to avoid adding fuel to the fire. Patients can eat more foods such as mung beans, wax gourd, lotus seeds, bitter gourd, etc.
Pathological etiology
The etiology and inducing factors of eczema are often different due to individual factors and different stages of the disease, and it is not easy to determine. Inducing factors can be divided into external factors and internal factors. The former is common in food, such as fish and shrimp, and inhalants, such as pollen, dust mites and wool. Microbial infections such as purulent cocci and superficial fungi on the body surface, living environment such as sunshine, high temperature, dryness, various animal skins, dander, various chemicals such as cosmetics and soap, etc. Endocrine metabolic changes such as menstrual cycle, pregnancy and other factors, common blood circulation disorders such as leg eczema induced by varicose veins; Neuropsychiatric factors are also closely related to the occurrence of this disease, such as mental stress and excessive fatigue.
The individual's susceptibility or tolerance to various factors can also be enhanced or weakened by physiological or pathophysiological influences. In the same environment and conditions, some people are prone to eczema, while others are not. Some factors, under certain conditions, will aggravate the patient's condition, but in other cases, it will not lead to the recurrence of the disease. According to clinical manifestations, pathogenesis and histopathology, the pathogenesis of some patients may be related to delayed allergic reaction.
test method
1. Blood routine leukopenia
2. Zonk cytology was used.
Giant cells can be seen on the smear at the bottom of the blister.
3. Histopathology
Blisters or pustules can be seen in or under the epidermis, showing reticular degeneration and balloon degeneration, often with multinucleated epithelial cells, and a large number of inflammatory cells infiltrated in the dermis, mainly neutrophils.
complication
The prognosis of this disease is generally good, and other complications are not easy to occur.