Section I. Contact dermatitis
Contact dermatitis is an inflammatory reaction dermatosis that occurs mainly at the site of contact after the skin mucous membrane has been exposed to certain substances from outside. The substances that cause this disease are mainly animal, plant and chemical substances, of which chemical substances are particularly common. The pathogenesis of contact dermatitis is usually divided into two categories: allergic contact dermatitis and irritant contact dermatitis. Other types include tachyphylaxis, phototoxic and photomimetic contact dermatitis, systemic contact reactions, and non-eczema-like contact reactions.
I. Allergic contact dermatitis
Allergic contact dermatitis is a T-cell-mediated delayed skin metaplasia caused by exposure to allergens. The substances exposed are mostly small-molecule chemicals, which are not irritating in themselves, and only a few sensitized people in the population develop the disease after exposure.
Clinical characteristics
1, there is a history of exposure, common exposure to allergens are: hair dye p-phenylenediamine; cosmetics, detergents and other aromatic compounds, preservatives, etc.; topical drugs such as red mercury, tincture of iodine, cool oil, sulfonamide and antibiotic topical preparations; chemical materials and products in the additives, dyes, synthetic resins, etc.; heavy metals such as nickel salts, chromium salts, etc.; animal skin, hair, insect secretions and plants such as nettle, raw lacquer, etc. Raw lacquer, etc.
2.The rash is erythematous, slightly edematous or with dense red papules; in heavy cases, the erythematous swelling is obvious, with dense red papules, papules, blisters and even blisters, but the clinical evidence is dominated by a single damage.
3, the rash occurs at the same location and extent as the allergenic contact site, with clear boundaries. The rash can be widespread when the body is highly sensitive. The onset of the disease has a certain incubation period, ranging from a few hours to 10 days, generally re-exposure to more than 24 to 48 hours onset.
4.Self-perceived intense itching, burning or swelling sensation. Systemic symptoms are often not obvious.
5, the course of the disease more acute after a self-limiting, remove the cause, properly handled, about 1 to 2 weeks can be cured, but re-exposure can recur. If repeated exposure or improper treatment, it can turn into subacute or chronic dermatitis.
6, the cause of unknown or more exposure, do patch test to help determine the allergen.
7, the disease needs to be distinguished from acute eczema, the cause of acute eczema is often unknown, the rash is polymorphic, more vesicular exudate, unclear boundaries, easy to recur, according to this can be distinguished.
Treatment
I. Treatment principles
Find the cause, remove the cause, once diagnosed should avoid re-exposure to allergens and their structural analogues. Wash the contact area thoroughly, avoid hot water, soap, scratching and other stimuli.
II. Local treatment
1. Acute lesions: without exudate, use glyburide lotion, 3 to 4 times a day for external use or when itchy. 2% to 3% boric acid solution or saline for cold wet compresses when there is exudate. If the lesion is secondary to infection, 0.05% berberine hydrochloride solution, 0.2% epsom saline solution or 1:8000 potassium permanganate solution can be used as cold wet dressing. According to the amount of skin lesion exudate for continuous wet compress or each wet compress 30-60 minutes, 2 to 4 times a day, intermittent or evening can be used topically 40% zinc oxide oil.
2, subacute lesions: after the lesions dry, switch to glucocorticoid cream. Can use 1% hydrocortisone cream or 0.1% hydrocortisone butyrate ointment (trade name Yuzor), 0.05%-0.1% dexamethasone cream, 0.1% tretinoin cream, etc., 2-3 times a day topical application. If there is still a small amount of exudate should be added at the same time with zinc oxide paste.
3. Chronic lesions: use glucocorticoid ointment or cream topically 2-3 times a day. Also can add zinc oxide, tar ointment, such as 10% zinc oxide ointment, 10% black bean distillate ointment, 5% to 10% furosemide ointment or 10% fisetin ointment, etc.
Third, systemic treatment
1, antihistamines: generally choose one of them orally. Such as chlorpheniramine, 4-8mg; dechlorperazine 25mg, 1 day 3 times orally. New generation antihistamines are less or no central sedation and anticholinergic effects, such as fexofenadine, 60mg, 2 times / d orally; cetirizine (trade name Xanthemin, Bevan, etc.) or loratadine (trade name Kerratan) or imipramine (trade name Petrone), 10mg, 1 day 1 time orally, can be used as appropriate.
2.Glucocorticoid: Glucocorticoid treatment can be preferred for those with severe or generalized skin rash. Adults with prednisone, 30-40mg / d, divided into 2-3 oral; or hydrocortisone, 150-200mg, add 5% to 10% glucose solution 500ml, 1 / d intravenous drip; or dexamethasone, 5mg, 1 / d intravenous or intramuscular injection. Gradually reduce the dosage after the inflammation is controlled, and stop using it within 2-3 weeks.
3.Non-specific desensitization treatment 10% calcium gluconate, 10ml, or sodium thiosulfate, 0.64g dissolved in 10ml of water for injection, 1/d intravenously; 5%-10% glucose solution in 500ml with vitamin C 2.0-3.0g, 1/d intravenously.
4, secondary infection Select effective antibiotic system or local topical treatment at the same time.
Second, irritant contact dermatitis
Irritant contact dermatitis, also known as primary irritant contact dermatitis, is caused by direct damage to skin cells from the irritant. The irritant itself has an irritating or toxic effect on the skin and can develop after any person is exposed to it. The extent of the irritant is related to the chemical nature of the substance, the concentration, the duration and extent of exposure. The strength of the irritant is divided into acute irritant contact dermatitis and chronic cumulative irritant contact dermatitis.
Clinical features]
(A) have a history of exposure
1, acute irritant contact dermatitis is the onset after contact with strong irritants, such as strong acids, strong alkalis, mustard gas, spotted vermicelli, etc.
2, chronic cumulative irritant contact dermatitis is the onset after contact with weak irritants, such as soap, laundry detergent, organic solvents, etc.
(B) skin lesion characteristics
1, acute irritant contact dermatitis in contact with irritants soon after the local appearance of erythema, swelling, blisters, erosion, and even skin necrosis, ulcers, etc.. The scope of the lesions is limited to the contact area, the boundaries are clear; they are most likely to occur on exposed areas, the hands are most susceptible, self-conscious burning and tingling sensation. Toxic absorption can appear after the systemic symptoms of varying degrees.
2, chronic cumulative irritant contact dermatitis need to be repeatedly exposed to long-term before the onset. Mainly manifested as local skin mild dryness, redness or roughness, flaking and cracking. It is more likely to occur in exposed areas, such as the back of the hand, fingers, face, eyelids, etc.. Self-perceived dry, itchy or painful skin.
Treatment
(A) Local treatment
1. Immediately detach and remove the contact material After contact with strong irritants, rinse locally with plenty of running water for at least 10-30 minutes.
2, the application of neutralizing agents on the basis of water rinsing adequately, for alkaline material damage with acetic acid, lemon juice and other weak acidic solution neutralization; for acidic material damage, with soap solution, soda and other weak alkaline solution neutralization. Note that the neutralizer should not be too early, and the neutralization time should not be too long, so as to avoid heat production in the process of acid-base neutralization reaction, aggravating the skin damage.
3, according to the characteristics of the lesions to choose the appropriate topical drugs (see topical treatment of allergic reactive contact dermatitis section). Note that the herpetic damage should be aspirated first before cold wet compresses. For dry, cracked damage can be added vitamin E cream, 10% urea ointment, 10% cod liver oil ointment and other topical applications.
(B) Systematic treatment
1, with pruritus can choose an antihistamine oral, such as chlorpheniramine (paracetamol), deslorpromazine, ketotifen or loratadine, desloratadine and cetirizine, etc..
2.People with obvious pain can be given analgesic and sedative drugs orally as appropriate.
3.Persons with extensive and severe skin lesions may be given short-term oral or injectable glucocorticoid hormones as appropriate.
4.Detoxification and accelerated excretion of toxic substances Sodium thiosulfate 0.64g dissolved in 10ml of water for injection, 1/d intravenous injection, or 5% to 10% glucose solution 500ml plus vitamin C 3.0g, 1/d intravenous drip.
5. If there is secondary infection, appropriate antibiotics should be selected for treatment.
Prevention】
1, should avoid contact with irritants as far as possible, such as work or daily life needs, should strengthen personal protection, such as wearing gloves, protective clothing, wearing a mask or external application of protective cream cream.
2.Improve labor conditions, and strive to automate operations.
3, after contact with irritants or substances of unknown chemical nature, immediately rinse fully with running water or use other effective neutralization methods to remove it.
Section II eczema
Eczema is caused by a variety of complex internal and external factors, a polymorphic lesions and the tendency to exude inflammatory skin reactions. The cause of the disease is complex and difficult to determine. Self-perceived symptoms are intense itching. The disease is easily recurrent and can be prolonged for many years.
Etiology and pathogenesis
(a) Genetic factors Some types of eczema are closely related to genetics.
(B) environmental factors The influence of environmental factors mainly refers to the increasing number and complexity of environmental allergens, including.
1, artificial fabrics, artificial leather products, and clothing-related printing and dyeing agents bleaching agents, brighteners, moth-proofing agents, anti-mildew agents, firming agents and other modern clothing environmental allergens.
2, artificial food, convenience food, anti-seasonal food, fertilizers, pesticides, artificial feed, feed additives used in food production, preservatives, mineral oxidizers, spices, pigments, ripening agents, thickeners, etc. used in food processing, modern diet environmental allergens.
3, man-made building components, chemical coatings, plastic products, rubber products, artificial fibers, adhesives, waterproofing agents, electromagnetic radiation generated by electronic equipment in homes and offices, household cleaners, pesticides, the function of modern housing environmental allergens.
4.The gases generated by the combustion of chemical fuels, the materials used in the manufacture of automobiles, boats, and airplanes, the asphalt pavement of roads, the pollen of roadside greenery, and other environmental allergens of modern transportation.
5, detergent factories in the manufacture of detergent all the enzyme preparations, plastic factories of toluene diisocyanate, rubber factories of latex, pharmaceutical plants of antibiotics and other chemical raw materials and other modern occupational environmental allergens.
6, certain modern lifestyles related to environmental allergens, such as the use of cosmetics and cats, parrots, etc., when the human body lives in this adverse environment for a long time, can lead to immune dysfunction and eventually cause a metamorphic reaction to the environment, thus causing eczema.
(C) infection factors some eczema and microbial infections, these microorganisms include Staphylococcus aureus, Malassezia, airborne fungi such as Streptomyces, Mycosphaerella, Penicillium, Aspergillus, Fusarium, Aspergillus, Aspergillus and Black root mold, etc.
(D) dietary factors human food varieties, generally can be divided into plant, animal, mineral, in recent food is often applied to some chemical synthesis of food such as saccharin, acetic acid, citric acid, flavors, synthetic dyes, etc., these foods can cause food metamorphosis.
(E) drug factors
1, ethylenediamine antihistamines such as aminophylline, piperazine, procaine, para-aminosalicylic acid, iodide and organic iodide, X-ray contrast agents, etc. mainly cause systemic contact type drug dermatitis.
2, ampicillin, amoxicillin, nickel, heparin and mercury cause Foiboon syndrome.
3, penicillin, methyldopa.
Clinical manifestations
1, the rash is polymorphic, according to the characteristics of lesion performance is divided into acute, subacute and chronic eczema three.
(1) Acute eczema: acute onset, often symmetrical distribution, to the head and face, the extremities and vulva, most of the corn-grain red papules, papules or blisters, there are still obvious points or small pieces of vesicles, exudate, crust. The lesions are poorly defined. In combination with infection, pustules, purulent exudate, and scabs may appear. There are often 2 to 3 types of rashes coexisting or a certain type of rash predominates at a certain stage, often aggravated by intense itching and frequent scratching.
(2) Sub-acute eczema: often due to improper treatment of acute damage, the lesions are mainly red papules, maculopapular rash, scales or crusts, with a few papules or blisters and vesicular ooze.
(3) chronic eczema: more acute, subacute eczema repeatedly does not heal transformed from, can also begin to present chronic inflammation, the affected skin infiltration thickened, become dark red and pigmentation, persistent when not healed, lesions thickened, often fused thickening moss-like changes, the surface has scales, scratches and blood crust, scattered around a few papules, maculopapular rash, etc.. The lesions are dry and prone to cracking, and are commonly found on the lower legs, hands, feet, elbow sockets, vulva, anus, etc. The skin lesions can be acute under certain triggers.
2, the rash can occur in any part, but the exposed parts and flexural side is common; rash often symmetrical distribution. Common site-specific eczema are ear eczema, hand and foot eczema, breast eczema, eczema of the external genitalia of the anus, calf eczema, etc.. Conscious itching is intense.
3, the course of the disease is irregular, often recurring and difficult to heal.
4, the clinical diagnosis of eczema, eczema symptoms by disease type are as follows.
(1) infant eczema: infant eczema Chinese medicine called milk ringworm, usually in the second or third month after birth began to occur, usually on the face and skin folds, can also involve the whole body, generally with the increase in age and gradually reduce to heal, but there are a few cases continue to develop into childhood and even adulthood.
①Exudative eczema: common in obese infants, initially on both cheeks, erythema, papules, papules, often due to severe itching and scratching and reveal a lot of oozing bright red vesicles, serious cases can involve the entire face or even the whole body, such as secondary infection can be seen pustules and local lymph node enlargement, fever.
② dry eczema: mostly seen in thin infants, preferably on the scalp, between the eyebrows and other parts, manifested as flushing, flaking, papules, but no significant exudation, chronic when also mildly infiltrated hypertrophy, chaps, scratches or crusts, often due to paroxysmal intense itching and cause crying and sleep disturbances in infants.
(2) children’s eczema: is a child allergic skin disease, children’s skin development is not yet sound, the outermost epidermis of the stratum corneum is very thin, capillary network is rich, the endothelium containing water and chloride is rich, so it is easy to allergic eczema reaction.
(3) Breast eczema: mostly seen in breastfeeding women, the areola is moist, erosion, crusting, a little time can be thickened, chapped, painful when breastfeeding, long-term failure to heal, subcutaneous hard nodes, should consider the possibility of complications eczema-like cancer, so breast eczema should be vigilant, timely examination.
(4) Scrotal eczema: in acute cases, there is swelling, running water, crusting, in chronic cases, there is thickening, mossing, very itchy and easy to recur, often related to local sweating, vulvar irritation, neuroendocrine disorders, chronic prostatitis, etc.
(5) Female eczema: Mostly seen in the labia majora and minora and nearby skin redness, erosion and chronic thickening, very itchy, often related to mycosis fungoides, leucorrhoea and endocrine disorders.
(6) anal eczema: perianal eczema in the acute phase is red, swollen, erosion, chronic phase is infiltrated, hypertrophy, and even chapped, itchy and painful, especially after the stool is more obvious, due to frequent scratching, the skin can be thickened or thinned, atrophy and shiny, children’s anal eczema is mostly related to pinworms, adults are more related to hemorrhoids, sweating.
(7) hand eczema: occur in the palm of the hand easy to infiltrate thickening, hyperkeratosis to form chaps, finger end eczema often repeated blisters, crusting, thickening, flaking, involving the nail bed can affect nail development, resulting in rough nail plate, sunken uneven, contact with water, soap, laundry detergent, etc. often make eczema aggravated.
(8) leg and foot eczema: prevalent shin and ankle, often caused by varicose veins or trauma to the lower extremities, crusting, thickening, mossy, can also be vesicular, oozing, easy to secondary infection or the formation of ulcers, stubborn and difficult to treat.
(9) chapped eczema: allergy-related, caused by daily exposure to detergents, soaps, dyes, paints and sunlight and other irritants, in the course of the disease, mental trauma, endocrine disorders and other factors can aggravate the disease
Diagnosis】
1, according to the acute phase of the primary rash of lesions polymorphic, easy to have exudate, itching, intense, symmetrical episodes and the chronic phase of infiltration, hypertrophy and other features of diagnosis is not difficult, acute eczema need to be distinguished from contact dermatitis, chronic eczema need to be distinguished from neurodermatitis, hand and foot eczema, sweat vesicles easily confused with ringworm, the latter often unilateral onset, slow progress. The latter often starts unilaterally and progresses slowly. There can be small blisters and dry flaking, and when it spreads to the hands and the back of the feet there is a great diagnostic value when there is damage with clear edges, and the diagnosis can be confirmed when the fungal examination is positive.
2, the disease should be distinguished from contact dermatitis, neurodermatitis, seborrheic dermatitis, etc.
Treatment
I. General treatment
1, should be as far as possible to find the cause of the onset or trigger aggravation of the patient, detailed medical history, work environment, habits, thoughts and emotions, etc.; for allergen testing, such as skin prick test or intradermal test, specific IgE antibody and patch sieve test, in order to find possible allergens.
2, as far as possible to avoid external bad stimulation, such as hot water washing, violent scratching, etc.; try not to wear chemical fiber intimate underwear, fur products; avoid eating easily allergenic and irritating food, such as seafood, chili, wine, coffee, etc.
3, keep the skin clean, prevent skin infection, avoid overwork, maintain an optimistic and stable mood.
Second, local treatment
The medication should be mild and non-irritating, depending on the stage of the disease and the lesions.
1, acute eczema: no exudation, furnace glycolate lotion, 4-6 times a day for external use. If itching is obvious, add glucocorticoid cream for external use. Such as 1% hydrocortisone cream or 0.0.1% hydrocortisone butyrate ointment, 0.1% tretinoin cream or 0.1 mometasone furoate cream (trade name Eloson), etc., 1 to 2 times a day for external use. When there is exudation, first with 2%-3% boric acid solution or saline for cold wet compress, 30-60 minutes each time, 2-4 times a day wet compress or continuous wet compress, wet compress interval or evening available 40% zinc oxide oil topical application, after the reduction of exudation change to zinc oxide paste.
2, subacute eczema: can be used as a paste, such as zinc oxide paste or 5% furfuryl distillate paste, glucocorticoid cream agent, 2 to 3 times a day for external use.
3, chronic eczema: glucocorticoid cream agent, ointment or hard cream, zinc oxide ointment agent tar-based ointment can be used.
4, eczema secondary infection: such as secondary bacterial infection, in addition to the choice of wet dressing solution with anti-infective effect such as 0.05% eosin solution wet dressing, available glucocorticoid antibiotic mixture, such as trimethoprim chloramphenicol cream for external use, or add 2% mupirocin ointment (trade name Baedobang) or 2% fusidic acid cream (trade name Listerine) or 1% erythromycin ointment for external use, 2 to 3 times a day; such as secondary fungal infection, can be combined with topical antifungal drugs. Commercially available glucocorticoids, antifungal drugs and antibiotics mixed topical preparations, such as dermatological cream, paregoric ointment, compound Conrad cream, etc., can be used as appropriate.
5, glucocorticoid intra-dermal injection: for small pieces of hypertrophic and stubborn damage and coin-shaped eczema, such as 2.5% to 5% prednisolone acetate suspension or tretinoin suspension or betamethasone injection (trade name Depo Pine, 1ml containing betamethasone dipropionate 5mg, betamethasone sodium phosphate 2mg) plus an equal amount of 1% to 2% procaine or 2% lidocaine, do damage or dermal superficial local Prednisolone acetate suspension is injected once every 1 to 2 weeks, and the latter two drugs are injected once every 3 to 4 weeks, for a total of 3 to 4 times. Attention should be paid to the occurrence of side effects such as local skin atrophy.
Third, systemic treatment
1, antihistamines: traditional antihistamines mostly have a central sedative effect, such as paracetamol, deslorpromazine, cycloheximide. The new generation antihistamines have less or no central sedation and dry mouth side effects, and can also be used. Such as cetirizine, levocetirizine (trade name Youze), loratadine (trade name Kerratan), dexloratadine (trade name Enristine), imipramine (trade name Petrone), can choose one or two of them as appropriate. The safer drugs for pediatric patients are 0.2% Benadryl syrup or chlorpheniramine.
2.Non-specific desensitization therapy: 10% calcium gluconate, 10ml or sodium thiosulfate, or a combination of 5% to 10% glucose solution in 500ml with vitamin C 2.0-3.0g, also available diammonium glycyrrhetinate (trade name Glycyrrhizin) or compound glycyrrhizin injection, 1 to 2 weeks for a course of treatment.
3, glucocorticoids: can quickly control the symptoms, but stop the drug is easy to relapse, so the general situation does not advocate the application. Only in acute eczema severe, extensive rash or eczematous erythroderma patients, the use of other treatments are ineffective and no contraindications to the application of glucocorticoids can be used as appropriate, such as prednisone, dexamethasone, betamethasone. Note that it is not advisable to reduce or stop the drug too quickly, so as to avoid the rebound phenomenon to make the disease repeated.
4.Reigengteng preparation: At present, the general use of Reigengteng multi-glucoside tablets.