Eczema is a common disease in dermatology, accounting for about 20% of dermatology outpatients. It has a complex etiology, is easily recurring, and is one of the most difficult diseases in dermatology. Dermatology clinicians diagnose a large number of “eczema” every day; however, many people do not have the same understanding of eczema, especially the lack of good countermeasures for recurrent eczema. Therefore, the search for the causes of eczema development and effective prevention and treatment methods is the focus and difficulty of clinical research.
I. Etiological analysis
Although many scholars have different views on the concept and classification of eczema, the more recognized basic understanding of eczema is consistent, that is, eczema is caused by a variety of internal and external factors, with polymorphic rash, accompanied by intense itching, prone to recurrent and chronic. It is generally classified as acute eczema, subacute eczema and chronic eczema.
Eczema is generally considered to be a delayed allergic reaction, mostly related to genetic factors, and the allergens are external or self-sensitizing factors. Sometimes bacterial and fungal infections can form super antigens. In addition, some diseases cause immune imbalance, or the integrity of the local blood vessels, lymphatic reflux is disrupted are triggering factors.
External stimuli such as sunlight, ultraviolet light, cold, heat, dryness, sweating, scratching, as well as animal fur, plants, chemicals, cosmetics, soap, artificial fibers, etc. can trigger eczema. Certain foods can also make eczema worse in some people.
Intrinsic factors such as chronic digestive diseases, mental stress, insomnia, overexertion, emotional changes and other mental factors. Metabolic disorders, endocrine dysfunction, etc. can produce or aggravate the condition of eczema.
Second, aggravating factors.
1.
Itching is the main symptom of eczema, often causing a strong scratching response; scratching can cause superficial erosion, bleeding, infection or moss-like changes, and sometimes can form a significant hyperkeratosis. Scratching therefore plays an important role in stimulating or making eczema persistent. Control itching, reduce scratching, is an important means of treating eczema.
2, the role of pathogenic bacteria and their toxins, eczema lesions and their exudate is a good medium for the growth of a variety of microorganisms, eczema trauma is prone to secondary infection, the direct toxic effects of microorganisms and their antigens or superantigens inspired by the immune response and metamorphosis can make eczema aggravated.
3, constant contact with allergens, especially the more hidden allergens, sometimes a very small amount of contact can promote an eczematous reaction. In these cases, the rash is mostly asymmetric. For example, it has been reported that in chronic depressive eczema of the lower leg with dissemination, 90% of cases are positive for topical patch test, suggesting that this dissemination is caused by the continuous absorption of topical medication in patients with hypersensitivity status.
4, by ingestion or injection of the same or similar chemicals as the initial sensitization, such as topical or systemic medication can cause eczema to recur or spread, causing generalized recurrent eczema. In these cases, the rash tends to be generalized, and often sudden onset.
5, “autosensitivity”, is the patient’s own skin lesions suffered by the stimulation of the formation of certain substances after absorption, allergic skin inflammatory reactions caused by. The allergenic substance may be the product of bacteria or fungus or the patient’s own tissue proteins through some process and the formation of auto-antigen.
6, improper treatment, such as the use of overly irritating topical drugs, or allergy to the use of topical drugs, improper selection of the dosage form of topical drugs; or the systemic use of glucocorticoids or other immunosuppressive drugs to reduce the dosage too quickly or stop the drug too early caused by the symptoms of “rebound”.
Prevention and control measures
1. Ask for medical history, first of all, consider whether it is atopic dermatitis, contact dermatitis and other diseases. The first thing to consider is whether it is atopic dermatitis, contact dermatitis, etc. Early stage of cutaneous T-cell lymphoma, breast or extramammary Paget’s disease, tinea cruris, etc. should be excluded. In addition, some systemic diseases can also be accompanied by dermatitis eczema-like changes.
2, so that patients understand the occurrence of eczema, the development of the law and prevention methods, and actively cooperate with treatment. Such as scratching, infection, etc. Actively control pruritus, secondary infection, prevent vicious cycle, and promote wound healing.
3. Use patch test・, intradermal test, allergen in vitro detection test, excitation test and other methods to find exogenous causes or aggravating factors. The immune function and endocrine function of the body should be tested to help find endogenous causes or aggravating factors, and try to avoid and remove them.
4. In particular, avoid external stimuli such as scratching, hot water scalding, long bathing time, soap scrubbing, etc. Eat less or no allergy-prone and irritating food, such as seafood, coffee, chili, wine, etc. Underwear and underwear should be pure cotton, and those who are allergic to animal fur should avoid wearing woolen clothing.
5. Sensitive people should reduce or avoid contact with common allergens such as dust, dust mites, pollen and pet fur in the environment. Indoor temperature should not be too high, avoid overheating and sweating.
6, the body’s immune and endocrine function abnormalities, is also one of the reasons for the persistence or secondary spread of eczema. Pay attention to adjust the overall state of the body’s immune and endocrine function, is very important in the treatment of eczema, and easy to ignore the link
IV. Treatment
1, itching is the main conscious symptoms of eczema, the more serious should be given sedative drugs, should choose a generation of antihistamines, such as paracetamol, cycloheximide, ketotifen, etc.. Second-generation antihistamines generally do not have a central sedative effect on the itching of eczema is not effective.
2, topical corticosteroid ointment, applied to the lesion area, twice a day, morning and evening. Generally use 2 to 4 weeks to cure. For chronic eczema lesion hypertrophy, local sealing method can be used to improve drug efficacy and prevent patients from scratching.
3, facial eczema as far as possible without hormonal creams, more serious can use tacrolimus ointment.
4, for extensive secondary infection, should be combined with effective antibiotic treatment. In addition, vitamin B, vitamin C and drugs that regulate nerve function are also helpful.
5, for generalized eczema, a small amount of oral corticosteroids can be taken, the role of anti-inflammatory, antipruritic to reduce exudation faster, but often relapse after discontinuation of the drug, should be gradually reduced. Can also be taken orally Reglan, white peony total glucoside capsule, Mennen, etc.
V. Precautions
1, eczema is not contagious Eczema is not caused by unhygienic, too frequent washing or bathing with very hot water will instead destroy the skin barrier, inducing and aggravating the condition.
2, adhere to the use of moisturizers to prevent recurrence Ruijin Hospital Department of Dermatology after long-term observation, the use of moisturizers with skin barrier protection function after bathing can play a supplementary treatment and significantly reduce the role of recurrence.
3, usually wear cotton soft underwear, avoid scratching and rubbing the skin.
4, many patients believe that eczema is caused by diet, but there is no evidence of the existence of foods that can cause eczema. Therefore, unless the evidence is conclusive, do not abstain from eating to avoid malnutrition.
5, treatment. Reasonable topical glucocorticoids, do not be overly afraid of their side effects; in the acute phase of the attack can also be small doses, short injections or oral hormones to control acute inflammation. For eczema occurring on the face can be preferred to non-hormonal such as tacrolimus ointment. Narrow-wave ultraviolet irradiation is also a very effective way to control the condition and reduce the amount of hormones. Severe eczema on the hands and feet can be treated with PUVA (topical photosensitizing substances after ultraviolet irradiation).
6, careful search for the cause. If there is no eczema originally, suffering from hypertension and developing after taking medication, it may be related to calcium ion antagonists in antihypertensive drugs; eczema occurs after suffering from dermatophytosis (such as ringworm, nail fungus, ringworm, etc.), especially in patients over 50 years old, it may be related to the immune imbalance of the body.