Scabies
Introduction
Introduction to acne Acne is a chronic infectious skin disease caused by human mistletoe in the surface layer of human skin. The disease is highly contagious. It is mainly transmitted through close contact, and can also be indirectly transmitted through clothing. It can be popular among families or groups of people. The mites are parasitic in the skin, excavating mechanical irritations in the "tunnel", and allergic reactions caused by their secretions and excretions, causing severe itching of the infected person's skin, especially at night (because the mites are more active in the evening). The disease mostly occurs in winter, the duration of the disease varies, and some can be delayed for several months. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: contact spread Complications: acute nephritis dermatitis
Cause
Causes of acne
Delayed allergic reaction (30%):
The incidence of hemorrhoids, delayed allergic reaction plays an important role, and in the acne infection period, the detection of serum immunoglobulin levels can slightly reflect the activity of B cells, IgA decreased significantly during infection, and IgG and IgM levels increased significantly. After treatment, it returned to normal. The level of IgE in the serum of patients with acne was significantly higher than that of normal people. After the patient was cured, the level of IgE decreased, and the IgE produced by sputum infection was specific, and it had no crossover with the dust mites antigen.
Hoefling used immunofluorescence technology to detect IgM and C3 deposition in the dermal wall of patients, which is like cutaneous vasculitis. The dermal junction has granular IgM, IgG deposition, and lupus erythematosus. Neste et al detected in the patient's serum. The antigen-antibody complex of complement C1q has been found to have been damaged by Langerhans cells in the epidermis, the density of the cells is decreased, the dendrites are reduced or shortened, or the cell bodies are enlarged, and intracellular vacuoles and mitochondrial sputum rupture are treated. One year of acne patients often have hypersensitivity reactions to sputum extracts, and patients with nodular acne have deficient T cell function.
Skin damage to acne can be caused by several reasons:
1 Acne pruritic red pimples are caused directly by drilling into the skin.
2 The formation of blisters or small pustules may be excretion in the sacral or cerebral layer, which acts as a sensitizer to cause exudation of the epidermis and dermal capillaries.
3 tunnel system caused by locust excavation.
4 Nodules are hypersensitivity reactions of the body to aphid antigens.
Route of infection (30%):
Direct infection: It is an important way to spread acne after being directly infected with a patient or animal carrying a mites. In general, after the family or unit, dormitory has hemorrhoids patients, other people re-infected with hemorrhoids are transmitted by this route, the transmission is very strong, the infected population is extremely wide, adults, children, pregnant women, babies can be infected with hemorrhoids, all industries can cause hemorrhoids Disease transmission, doctors, nurses, teachers, students, workers, civil servants, etc., before the liberation occurred in rural areas with poor living conditions, the current living standards have improved, many people and doctors have ignored the occurrence and development of the disease, while large cities The floating population has an increasing trend.
Indirect infection: infection is caused by indirect contact with acne patients' clothing, supplies, furniture, articles, etc., and the most serious acne spread is strong (the money that acne suffers is exposed to other people will infect acne, take the bus Anyone who has been caught by a person with acne will be infected with acne.
Low autoimmunity (25%):
However, many people live with acne patients without disease, which has a great impact on the body's own immunity. The incidence of acne patients often occurs in the case of reduced autoimmunity.
Pathogenesis
Immunofluorescence studies suggest that there are vasculitis-like changes in the skin and blood vessels, and IgM and C3 complement conjugates are present, indicating that acne has humoral immune components, and histology suggests that cellular immune responses are triggered in general acne lesions, such as lesions. Most of the infiltrating cells around the papules, nodules, etc. are lymphocytes, and mainly T lymphocytes.
Prevention
Acne prevention
(1) Pay attention to personal hygiene. For contaminated clothes, bedding, bed sheets, etc., use hot water to wash and disinfect the insects. If it cannot be washed, it must be placed in the sun for more than 1 week.
(2) Eliminate unclean sexual intercourse.
(3) Take a bath in a business trip, pay attention to changing sheets.
The care of acne must first be cleaned in time, especially for clothes, bedding, and daily necessities that may be contaminated. Secondly, to avoid excessive scratching, it is necessary to cut nails in time to prevent infection by purging and purging. Bathing and changing clothes should be timely.
Once acne is found in a collective unit or family, it is necessary to isolate and give active treatment as soon as possible to prevent the infection.
Complication
Acne complications Complications acute nephritis dermatitis
Due to itching and scratching, it can cause bleeding or secondary infection, causing complications such as abscesses and folliculitis.
Symptom
Acne symptoms Common symptoms Itchy pimples have small blisters on the hands, acne fear, light night, heavy itching, acne nodules, winter skin, itching, miliary papules
symptom
When infected with acne, the first symptom is skin itching, and a small rash, small blisters or scars on the itching area. Its itching is very dramatic, generally lighter during the day, the night is aggravated, often due to scratching, scars, and even blood spots, the patient is difficult to fall asleep, after the mites penetrate the epidermis, it usually takes 20-30 days of incubation to appear rash And itching symptoms.
The rash on the beginning is more common in the moist and soft parts of the skin. For example, the skin between the fingers and the wrist is easy to wear the main parasitic, and then spread to other parts of the body, such as the elbow, waist, armpit, abdomen and genitals. Before the liberation, the folks circulated the "hemorrhoids like a dragon, first in the hand, three rounds around the waist, and a big camp on the legs."
Acne classification
(1) Adult acne: The main symptoms are itching, red papules, small herpes blisters, tunnels, nodules and crusting.
(2) Acne in the elderly: Itching is severe and the reaction to aphids is weak, so there is no obvious inflammatory reaction, and the back is more common.
(3) Infants and young children's hemorrhoids: it is difficult to find tunnels and sputum, the rash should be atypical, and it should occur on the head and face. The tunnel is light and shallow, looming like a line, the base is mildly inflammatory and pink, easy to accompany water. It is ill and easy to see through the stratum corneum, showing white spots.
(4) Nodular acne: more common in the capsule, hip, abdomen and thigh. It is reddish-brown to the knot, itchy, and it gradually fades after several months to more than one year.
(5) Norwegian : (Norwegianscabies), also known as molting acne, this type is Dabielsen in 1844, a type of acne that was first reported in Norway in 1848, so it is called Norwegian acne. It is an immune abnormal reaction that occurs mostly in patients with frailty, psychosis, immunodeficiency, and a large number of corticosteroids. It is characterized by dry skin, crusting, keratotic plaque plaques, erosive, pustules, foul odor, dry hair loss, thickened and twisted nails, swollen whole body lymph nodes, thick scales, and serious illness. Very contagious.
(6) Localized hemorrhoids.
Examine
Hemorrhoids examination
According to the history of contact infection, the predilection site of skin lesions, itching, tunnel and herpes-based rash, often a family with the disease, is not difficult to diagnose, if you can find sputum, the diagnosis is particularly true.
inspection method:
(1) Method of finding a tunnel
Use blue ink to drip on the suspicious tunnel skin lesions, then wipe with a cotton swab for 30 seconds to 1 minute, then use the alcohol cotton ball to remove the black marks on the surface, which can be seen as a light blue tunnel trace.
(2) Needle picking
On the finger side, palm wrinkles and blisters, pustules, etc. found a locust tunnel, and carefully found the end of the tunnel to find white insect spots, the most easy to find mites rash.
Method: The needle No.6 was selected, and the needle was placed at an angle of 10°20° to the plane of the skin. The needle was inclined upwards. At the end of the tunnel, the insect point was about 1mm perpendicular to the long axis of the tunnel, and the needle was inserted directly into the insect. Click on the bottom of the point and bypass the insect body, then flatten the needle to dry (5°-10°) and rotate it slightly. The mites fall into the hole of the needle hole, slowly picking up the needle (or directly exiting) and moving to On a slide with water (or 10% KOH, NS), then look for the mites under the microscope.
(three) scraping method
Advocate the pimples to use this method to check, first use a sterile surgical blade to dip a little mineral oil, look for new inflammatory papules, scrape the number to scrape the horny part of the top of the pimples, to the small points in the oil droplets, even After scraping 6-7 papules, move to the slides. The larvae are often found under the microscope, and there are occasional eggs and insect feces.
Commonly known as aphids, it is a kind of intradermal parasite. There are many types of human acne. The human acne is mainly caused by human mites. The mites are divided into male and female. The females are about 400 m long and can be seen by the naked eye. The mature females are The oval-shaped flat body is yellow-white, it has no clear head, but the mouth protrudes from the front edge of the body. It is often mistaken for the head. It has four pairs of feet, each with 5 knots. The first 2 pairs have suction cups, and the last 2 pairs are Long-tailed bristles, one in the center of the abdomen, one in the center of the abdomen, the anus in the center of the torso, the male is half smaller than the female, the aphid crawls quickly on the warm skin, 2.5 cm in 1 minute, mature female In the appropriate skin area, enter the horny layer hidden underneath, use the first two pairs of claws to cut into the junction of the horny and granular layers, from which the cells absorb nutrients.
The life history of cockroaches is four stages: eggs, larvae, nymphs and adults. Mature females are 0.5-5mm per tunnel, and the first egg is laid in the squatting hours. 40-50 eggs can be laid every day. At the same time, the feces are discharged, and the eggs are dead at the blind end of the scorpion. The females live on average for 6-8 weeks.
The egg is oval-shaped, yellowish in color, and the shell is very thin. It is about half the size of the female. After 3-4 days of hatching in the stalk, the egg forms a larva. Its shape is similar to that of an adult. There are only three pairs of feet. Keep the inside of the squat for 1 day, then move on the surface of the skin, and then quickly cut into the skin, and hide and ingest food in the sac. The larvae become nymphs in about 3 days, and the nymphs have four pairs of feet. At this time, the male and female nymphs mate at the epidermis at night, and most of the males die after mating. The female nymphs mate into the stratum corneum of the human skin for 2-20 minutes, and soon the sable becomes an adult, and then the egg cells are fertilized in the body. In 2-3 days, the eggs are laid in the tunnel, and the eggs are laid while advancing. After that, the females die in the ramps, and the eggs are grown for about 7-10 days.
There are two kinds of pathogenic factors of cockroaches. One is the mechanical damage caused by mites in the stratum corneum of the skin, and the other is that the toxins secreted by the mites stimulate the skin to itchy.
often invade the thin and tender parts of the skin, so the damage occurs in the finger joints, wrist flexion, elbow fossa, armpits, women's breasts, umbilical cord, waist, lower abdomen, medial femoral, external genital and other parts, more symmetrical, On the head, the palmars are not easily affected, except for infants and young children, who often wash their hands, and have no damage or only a few hands.
The rash is mainly papules, blisters, tunnels and nodules. The papules are about the size of millet, reddish or normal skin color, inflammatory redness, often scattered or densely integrated, rarely fused, and some can evolve into herpes, blister From rice grains to mung beans, it is more common in the gap between the fingers. The tunnel is grayish white or light black line, about 3-15 mm long, curved micro-long, often with papules and blisters at the end; some are not easy to see typical tunnels, may be cleaned , scratching or secondary lesions and destruction, nodules mostly in the scrotum, penis, labia majora, etc., about the size of peas, hemispherical, reddish, wind-like.
Consciously itchy, especially at night, may be caused by the aphid's strong activity in the warm bedding at night or the secretion of toxins that irritate the skin, due to scratching, scratches, crusting, eczema-like changes or causing Secondary infection, impetigo, folliculitis, sputum, lymphadenitis and even nephritis.
Diagnosis
Hemorrhoid diagnosis
clinical diagnosis
diagnosis
Hemorrhoids occur in the delicate and wrinkled parts of the skin, often starting from the finger joints. It can be widely transmitted to the upper limb flexor, elbow fossa, armpit, breast, lower abdomen, gluteal sulcus, external genitalia, and thigh within 1-2 weeks. On the upper side, occasionally invading other parts, but not invading the head and face, except for infants and young children, the baby's skin is relatively tender, and the mites are easy to invade the head and face of children.
Diagnosis of hemorrhoids: Acne is often accompanied by nocturnal paroxysmal pruritus, and the lesions are mainly red papules, herpes, small blisters, tunnels, nodules. Acne nodules are common in penis, scrotum, lower abdomen, etc., vesicles are common in finger joints, tunnels are specific skin lesions of acne, about 0.5mm long, slightly raised, slightly curved in pale gray or skin color, there is a A large grayish or reddish spot on the needle that is hidden by the mites.
Diagnosis of hemorrhoids, laboratory examination of hemorrhoids: scrape the dander from the affected area, such as papules, blisters, etc., and find aphids or eggs under the microscope; if a tunnel is found, use a needle tip to cut through the closed end, pick the naked eye to see The needles are large grayish white dots, and aphids can be found under the microscope.
According to the clinical characteristics of the above patients, it can be diagnosed as acne.
Differential diagnosis
The disease needs to be identified with the following diseases
Eczema: It is a pleomorphic skin lesion, often fused into a piece, tending to moist and ooze out, and there is no need for a good hair.
Itching rash: occurs in the extremities of the extremities, after chronic, from childhood, increased in autumn and winter, often complicated by inguinal lymphadenopathy.
Impetigo: It is good for children, with more exposed parts such as the head and face. It is a small pustule at first, and there is a yellow purulent after breaking. It is common in summer and autumn.
Papular urticaria: for most scattered small papules, herpes or hard vesicles, after the scratching, a small wheal is formed. After the wheal is regressed, it is still a small papule. The children are mostly allergic, often accompanied by gastrointestinal function. Obstruction and tonsil enlargement, easy to occur after insect bites.
Skin pruritus: There is no fixed position, finger joints are rare, the patient is mainly itchy skin, and the skin lesions are mostly secondary scratches. The onset is often related to mood swings, visceral diseases or menopause.
Rickets: The skin lesions are mainly secondary scratches. The two sides of the armpits, the waist, the genitals, etc., and the skin with the wrinkles of the garment are more common, and the eggs can be found.
