Atopic dermatitis: emphasis on external therapy

Atopic dermatitis (AD) is a chronic allergic recurrent disease of an inflammatory nature with age-related features of external (skin) manifestations that develops in children and adults with a hereditary predisposition. Synonyms: atopic, constitutional and endogenous eczema; neurodermatitis, allergic dermatosis, etc. AD is included in the WHO International Classification of Diseases.

Prevalence
The incidence of AD in the world reaches 15 or more cases per 1000 population and has a tendency to increase. Blood pressure accounts for 50-75% of allergic diseases. According to the WHO, annually up to 1 million people get sick with AD.

Pathogenetic factors and mechanisms
The nature and mechanisms of blood pressure are not fully understood. Important factors for the development of AD are stress, adverse environmental conditions, exogenous and endogenous allergens, neuroendocrine disorders, disorders of nonspecific and specific immunological reactivity, and heredity. In children of the first months of life, food allergies become important during artificial feeding or non-compliance with nutritional rules during pregnancy, intrauterine pathology. In children of the first year of life, attention is paid to the eaten chicken eggs, cow’s milk proteins, cereals, dysbacteriosis after uncontrolled intake of antibiotics, poorly treated foci of chronic infection, helminthiasis, etc. An important place belongs to inhalation allergens, in particular those formed by the interaction of medicines with bacterial, fungal and viral allergens. The weakening of the barrier function of the skin and the allergic orientation of skin reactions, along with the development of complex psychoneuroendocrine disorders, are important in the development of the underlying immunopathological inflammation in blood pressure. On the skin – external, but one of the most serious manifestations of blood pressure.

The
AD clinic usually manifests itself in the first months of life and initially takes a relapsing course with different remissions, frequency, severity and duration of exacerbations. Symmetrical erythematous-squamous, papular, erythematous-lichenoid, lichenified, exudative-cortical, pruriginous lesions with non-exudative lesions and with non-exudative lesions due to severe itching. Characterized by cheilitis, dark reddish circles under the eyes, foci of chronic infiltration, a puffy face with dry flaky skin and chapped lips. Often in the distal parts of the limbs, the process proceeds as eczema. Severe cases with increasing area of ​​skin lesion and increasing resistance to therapy are increasingly common.
Clinical and pathogenetic variants of blood pressure:
true (allergic) with a predominance of specific IgE-mediated immune mechanism;
mixed, with a combination of specific and non-specific mechanisms;
pseudoallergic with a predominance of nonspecific mechanisms.

Regardless of the options, the severity of blood pressure is determined not only by the prevalence and nature of skin lesions, but also, which is very important, by the organ manifestations of atopy (especially with regard to bronchial asthma and digestive system pathology).

There are 3 age periods in which blood pressure has its own characteristics:
infantile (up to 1.5-2 years) – acute exudative blood pressure with a predominance of hyperemia, edema, oozing and crusting;
from 2 years to puberty – chronic blood pressure with elements of lichenization, erythema and desquamation, hyperpigmentation in the lesions, excoriation due to itching, signs of vegetative-vascular dystonia;
from puberty – the predominance of infiltration with lichenization against the background of stagnant erythema, the appearance of itchy papules of normal skin color, merging into foci of papular infiltration.
By age 50, AD regresses.

Diagnosis is based on pruritus in combination with at least 3 of the following: a history of dermatitis on the flexor surfaces of the limbs (on the cheeks in children under 10), asthma or hay fever (atopy in the immediate family, for children under 4 years), recent generalized xerosis, eczema on the flexion surfaces of the limbs (in children under 4 years old on the skin of the cheeks, forehead and extensor surfaces of the limbs) and (if older than 4 years) the onset of the disease before the age of 2 years.
The diagnosis of blood pressure is standardized in accordance with the SCORAD system according to the area of ​​the body lesion, the intensity of clinical manifestations, as well as subjective signs – itching and insomnia. There is an atlas of reference photographs to evaluate the intensity (on a scale from 0 to 3) of erythema, edematous and papular elements, wetness, crusts, excoriation, lichenization and dryness.

Recommendations for care and drug therapy
Maintenance of the home
Regular cleaning and ventilation of the premises with maintaining low humidity are mandatory to reduce the likelihood of dust mites breeding. Exclusion from household goods of objects with which allergization is associated, refusal to keep animals, birds, aquarium fish. Caution about household chemicals.
Skin care
The skin is an object of special attention. Daily bathing cleanses and moisturizes the skin, creates a feeling of comfort. The water should be cool and dechlorinated.
Infusions of birch leaf, celandine grass, succession, decoctions of oak bark, burdock roots are added. The use of loofahs and rubbing of the skin is not recommended. Soaps and shampoos with a neutral pH level are used. After bathing and towel-drying, skin emollients are applied frequently enough to keep the skin soft throughout the day.
Diet therapy
Exclude products containing food additives, saturated meat broths, fried foods, spices, smoked meats, preservatives, liver, fish, caviar, eggs, cheeses, coffee, honey, chocolate, citrus fruits. They include fermented milk products, cereals, boiled vegetables and meat.
The best for a child in its first year of life is breast milk. There is practically no allergy to it, but in case of disturbances in the nutrition of a nursing mother, food antigens can enter the child’s body and cause blood pressure. Intolerance to cow’s milk proteins in children of the first year of life with AD occurs in almost 90% of cases. In case of intolerance, it is replaced with soy mixtures, and in case of allergies to them, with mixtures based on hydrolysis of cow’s milk proteins.

Drug therapy
To reduce neurotic reactions, sedative and psychotropic drugs are prescribed. To reduce signs of inflammation and itching in children over two years of age and adults, antihistamines and membrane stabilizing drugs (ketotifen, sodium cromoglycate) are used. It is advisable to prescribe enzymes (festal, mezim, etc.). Dysbacteriosis is an indication for the use of probiotics. Of the vitamin preparations, calcium pantothenate (B15) and pyridoxal phosphate (B6) are used.
Immunomodulatory therapy is carried out in cases of immunological deficiency. Systemic antibiotics are used at low-grade fever and lymphadenitis. In empiric therapy, preference is given to macrolides and cephalosporins of the 2nd and 3rd generations. Systemic corticosteroids are prescribed in the hospital in severe cases of blood pressure in short courses under the cover of antacids and calcium preparations.

Means of external therapy
External therapy takes a leading place in the treatment of patients with blood pressure and is aimed at suppressing signs of inflammation and improving the barrier functions of the skin.
An important place in external therapy belongs to corticosteroid agents in the form of emulsions, creams and ointments (topical corticosteroids – TCS), which, thanks to the versatile effects of anti-inflammatory action, contribute to the rapid resolution of exacerbation and improve the general condition of the patient. In the variety of TCS effects – hyposensitization of the receptors of the affected skin to histamine and serotonin, blockade of histaminase A2, inhibition of the synthesis of inflammatory mediators (prostaglandins,
leukotrienes, interleukins, complement components, etc.), immunosuppression with inhibition of the migration of lymphocytes and macrophages, delayed fibroblast proliferation and fibroblast proliferation. connective tissue structures, an increase in hyaluronidase activity with stabilization of cell membranes, a decrease in the permeability of the vascular wall, normalization of vascular tone, a decrease in the release of lysosomal enzymes, a decrease in exudative phenomena and skin itching. TCS cannot be avoided in the persistent course of blood pressure, especially with severe local lesions that are resistant to traditional drugs. They act on both the early and late phases of allergic inflammation.
External therapy is prescribed in accordance with the stage of blood pressure. In the acute stage, baths with decoctions of birch buds, chamomile, tea, sage are shown, as well as disinfectant solutions of potassium permanganate, furacilin, rivanol. Emulsions and creams are used from TCS for acute wetting processes; ointments are used for dry ones. As the process subsides, they switch to creams or ointments. Ointments are also preferred in the treatment of subacute and chronic skin manifestations of blood pressure.
TCS is used mainly in an open way, applying a thin layer to the lesions 1-2 times a day and rubbing into the pathologically changed skin. The skin is preliminarily cleaned of secondary layers – scales, crusts, residues of used drugs.
Monotherapy of TCS without supplementation with other external and systemic drugs is carried out for mild forms of blood pressure, as well as for relief of allergic manifestations of the inflammatory process on the skin. The duration of the use of TCS with mild blood pressure is 5-7 days, medium severe – up to 2 weeks and severe – up to 3 weeks.
During an exacerbation of chronic blood pressure, they are prescribed in short cycles lasting up to 2 weeks. Longer and over large areas of the skin application can contribute to the development of steroid skin dependence, as well as cause secondary infection.
Sluggish chronic inflammation requires the use of ointments, including under an occlusive dressing. With severe infiltration in the lesions, ointments and creams with keratolytic properties are prescribed. Upon reaching the therapeutic effect from the use of TCS in external therapy for a 1-2-week period, ointments containing naphthalan, birch tar or sulfur are included, alternating or combining them with corticosteroid ointments. This combination not only stabilizes the achieved therapeutic effect, but also prevents TCS withdrawal syndromes. It must be remembered that TCS is not used for individual intolerance, skin tuberculosis, syphilis, viral, bacterial and mycotic dermatoses, acne, skin tumors,
pregnancy, lactation, immunization and vaccination. Individual intolerance to TCS, however, is extremely rare.
Rational use of TCS allows achieving clinical remission and significant improvement in more than 90% of cases. The absence of color and odor in TCS has a beneficial effect on patients, convenience and comfort during treatment. They are valuable dermatological preparations for the successful treatment of blood pressure in inpatients and outpatients, regardless of age.
Among TCS, the absolute priority is given to non-halogenated drugs of the new generation, which are the most consistent with the principle of “treat quickly, effectively and pleasantly” due to the combination of high biological activity and safety. When pyoderma is attached, erythromycin, lincomycin and geoxysone pastes and ointments are used, as well as aniline dyes (methylene blue, fucorcin). The products containing tar, naphthalan and sulfur have already been mentioned. During active external therapy, frequent water procedures are undesirable.

Prognosis
Almost half of children with AD subsequently develop bronchial asthma, allergic rhinitis or hay fever. In this regard, it is extremely important to familiarize the patient and his family members with the causes of the development of skin rashes and itching, careful adherence to the doctor’s recommendations, and the unconditional implementation of preventive measures.

Prevention
Proper maintenance of the home, adherence to the diet, especially for pregnant and lactating women, priority of breastfeeding, limiting contact with inhaled allergens and household chemicals, hardening of children, effective intervention for colds and infectious diseases, the use of antibiotics for strict indications is necessary. Atopic dermatitis means a systematic approach to the patient, certainly with emphasis on local therapy with the timely and effective use of the new generation TCS.

event_note July 10, 2020

account_box Winona Tse MD

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