Atopic dermatitis (AD) is divided into extrinsic and intrinsic ones according to its pathogenesis and causative agents. Extrinsic AD is based on the barrier disruption, which allows external allergens to invade into the skin, leading to allergic or immunological consequences. This barrier damage-associated allergic mechanisms of extrinsic AD have been evident and supported by the discovery of filaggrin mutation, understanding of late-phase and delyed-type reactions, consensus of Th17 cells, and regulation of IgE. On the other hand, the mechanisms underlying intrinsic AD remain to be elucidated, and metal allergy, itch hypersensitivity, and others have been vaguely put forward to explain the pathogenesis. Since AD is thus heterogeneous, each early intervention should be evaluated on the basis of the paradigm of extrinsic and intrinsic AD. For example, topical immunomodulators seems to be therapeutically beneficial for extrinsic AD, while education intervention may be effective for both types of AD.

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The comparative studies of the prevalence of atopic dermatitis and skin barrier functions in Japanese and Chinese were performed. Clinical investigations were performed in elementary school students in Tibet Autonomous Region, Jiangsu Province in China and in Japan. Transepidermal water loss and capacitance were measured. Questionary survey about bathing frequency was also performed for students. The prevalence rate of atopic dermatitis was 0% in Tibet, 2.63% in Jiangsu Province, 4.26% in Japan. There was tendency that the prevalence of atopic dermatitis increased according to increase of TEWL. The environmental factors causing the difference of the prevalence rate of atopic dermatitis have been considered. These suggested that more investigations are necessary whether the development of habitat and environment influence the prevalence of atopic dermatitis and skin barrier function.

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Recently, relevance of environmental endotoxin exposure has been clarified in the pathogenesis of asthma and allergic rhinitis. As for atopic dermatitis, the results of family study and migration study have suggested the importance of hygiene hypothesis. Data relating to hygiene hypothesis and atopic dermatitis are reviewed in the present paper. At present, there are several limiting data supporting pathogenetic significance of hygiene hypothesis for atopic dermatitis. Further investigation would be warranted in this field.

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Atopic dermatitis (AD) is a multifactorial disease, however, the responsibility of house dust mites, such as dermatophagoides pteronyssinus (Dp) and farinae (Df) is considered as very high. Eviedence has been accumulated in the past 20 years that the responsibility of Dp for the production of elevated serum IgE of AD patients was 87.0% in 1991, and 77.2% in 2006. Patch tests of three live Dps and Dfs could provoke clear positive reactions of contact allergic nature on the second to 7th days of the patch test.
A new Methylene-blue-agar (MBA) method could demonstrate numerous Dps and Dfs in the interiors of the homes of AD patients, such as carpets, sofas, Tatami mattresses, chairs in the dining rooms, mattresses and blankets. Two randomized blind studies in Japan and the UK showed significant improvement of severe AD patients compared with controls, when mites were eliminated based on the mite fauna investigated in each patients’ home.
The importance of mite allergy in AD as well as the investigation of mite fauna in patients’ homes is stressed.

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It is well known that the water content and barrier function of the horny layer are decreased in patients with atopic dermatitis (AD), because the conductance of skin surface decreases and the transepidermal water loss (TEWL) increases. To examine the usefulness of these measurements for early diagnosis of AD, we measured the conductance and TEWL on the medical examination of infants and revealed that the TEWL in the uninvolved skin of abdomen significantly increased in infants with AD already as early as 6 months and 1.5 years old as compared with that in infants without AD. Accordingly, the measurement of TEWL in the skin is useful for early diagnosis of infantile AD and the early care on the skin of these infants might be expected to effect protectively on development and aggravation of AD.

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Malassezia species, currently classified into 13 species, colonize the skin of normal and various pathological conditions including atopic dermatitis (AD). Using a PCR-based, culture-independent method, Malassezia microflora of AD patients was analyzed. The lesional skin of AD showed higher detection rate and number of each species than non-lesional skin of AD and healthy subjects. Malassezia specific IgE antibody was detected only in AD patients. Systemic or topical antimycotics were effective for the head and neck type adult AD patients using topical steroids for a long time. Malassezia species are thought to be one of the factors aggravating AD.

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The recent health food craze has lead to the availability of a wide variety of health foods, including items that are expected to moderate the symptoms of various allergic diseases, such as atopic dermatitis (AD) and allergic rhinitis. Lactic acid bacteria, in particular, are attracting attention due to its favorable effect on AD in pregnant women and newborns as reported by Kalliomkái et al.
Immunologically, AD is a Th2 dominant disease. Its clinical course changes along with the balance between Th1 and Th2. Previously, we analyzed cases where patients of intractable AD experienced some moderation in symptoms over several months after being infected with varicella or measles. IL-12, produced in the eruption area to eradicate the infecting virus, acts on mite antigen responsive Th2 cells, switching the cytokine production pattern from Th2 type to Th1 type. It was concluded that this change in the balance of Th2 to Th1 lead to the moderation of AD.
Recently, in collaboration with the Functional Foods Division of Combi Corporation, lactic acid strains with strong IL-12 stimulation capability were identified, and the effect of lactic acid on allergic diseases were studied in animal and clinical experiments. NC mice were fed with lactic acid daily. Changes in skin conditions and the total IgE value in NC mice were observed over time. Fluctuations in antigen-specific IgE value and eosinophils counts were also studied using model mice with OVA-induced asthma. Moderation in AD skin conditions and suppression of IgE value were found in NC mice, and lower antigen-specific IgE and suppressed eosinophils accumulation in asthma model mice. In clinical tests, some preliminary improvement in symptoms and lower antigen-specific IgE value were observed in limited cases. In this seminar, these data will be introduced, and the effect of lactic acid on AD will be discussed.

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Family history of atopy and high level of IgE in cord blood can be relied on as indicators for the prediction of the future onset of atopic diseases in infants while predictive value is limited in sensitivity. It was found that sensitization occurred frequently before any known introduction of the food in the diet of the infants. Passage of small doses of maternal food antigens into the breast milk occurs and implies a possible rout of sensitization of the infants during lactation. However, maternal elimination diet during late pregnancy and lactation does not prevent the development of food allergy in the genetically predisposed children. Implementation of prophylactic maternal dietary avoidance is not recommended as the primary prevention of allergic diseases. Recently it was reported that oral Lactobacillus rhamnosus GG, probiotic bacteria strain, acted by generating immunosuppressive mediator in atopic children.

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To understand aggravating factors of atopic dermatitis, which are often difficult to determine in chronic patients, we performed a detailed questionnaire study in newly developed atopic dermatitis (AD) patients and patients who were possibly AD. Totally 123 subjects (male 36, female 87) were enrolled. They were divided into 3 groups (AD 50, eye lid dermatitis; ELD 26 and irritant dermatitis; ID 47) according to the distribution of the present skin lesions. Factors that were suspected to induce these disease groups were analysed from five fields 1. housing-related idems (house dust mite, pets, sick house, change of living place), 2. chemical skin irritation (occupational and house holding), 3. nature-related items (pollens), 4. physical stresses and 5. psychological stresses.

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Atopic dermatitis (AD) is a common, chronically relapsing skin disease. 10 years ago, the subpopulation of patients with adult type-atopic dermatitis was increased. Exacerbations of adult type AD lesions have been increased in such animal dander, house dust mites, cedar pollen, stress and soap. We addressed whether elimination of these exacerbation factors would be a good prevention for adult type-AD. In this paper, we focus on Japanese cedar pollen, focus of infection and detergents as a exacerbation factors. We concluded that atopy patch testing with Japanese cedar pollen extract is a useful method for investigating trigger factors for eczematous skin lesion in a subgroup of patients with atopic dermatitis and elimination of these factors could be a useful treatments for adult type-AD.

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About 30 percent of the patients with atopic dermatitis (AD), also suffers from seasonal allergic rhinitis are aggravated during the season when cedar pollens are dispersed in the air.
From the anatomical point of view, it is verified that the air-boarne allergen is highly adhesive to the eyelid which causes the eyelid dermatitis in these cases. Also, it is thought to be the IgE-mediated immune response against the cedar pollens. From the perspective of prevention and early intervention of AD, I examined the clinical features of the patients with a positive test result of cedar pollen on the prick test, who are suffering from AD and also eyelid dermatitis during the pollination season. We also considered an appropriate life guidance that should be performed towards the target.
Eyelid dermatitis was common among all age groups but women and the young adults were the majority. Scraping off their makeup is the one of the major cause for eyelid dermatitis. Tacrolimus 0.03% ointment is effective in these cases.
These results suggest that following guidance should be effective to prevent aggravation of eyelid dermatitis during the ceder pollination seaseon;
1) When you are exposed to the air containing pollens, the primary prevention is to cleanse off the pollens adhered to your skin surface right away.
2) Not just the facial cleansing but rinsing off the pollens on your hair will be more effective.
3) For those who wear makeup, it is important to cleanse off softly without rubbing your eyelids so hard.
4) Compared to steroid ointment, Tacrolimus 0.03% ointment is more effective and reduces the possibility of recurrence.
5) Internal use of anti-histamines for a few days will be effective as well, preventing habitual scatching.

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Atopic dermatitis is a chronic relapsing inflammatory allergic skin disease. For the management of AD, the inhibition of cutaneous inflammation and the improvement of skin barrier dysfunction is important. A Guideline demonstrating the intermittent use of corticosteroid and tacrolimus and the skin care is useful for the maintenance treatment. Early intervention is obtained by controlling the skin condition in the long term maintenance therapy, including decreasing the itch, getting high levels and QOL and the education about the treatment.

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We think the hospitalization treatment to atopic dermatitis is important from the viewpoint of intervention at the early stage. The questionnaire survey was done to 75 people who had experiences to be hospitalized in our department. The skin and the mental status, etc. before and after hospitalization besides sex and the age were examined, and comparison with the hospitalization treatment in other institutions was also performed, and the utility was referred.

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Atopic dermatitis (AD) is a multifactorial disease. When treating this disease, the features of individual cases need to be taken into account. AD is considered to involve two major mechanisms : the immunological mechanism (characterized by IgE dependency or type IV allergy) and the non-immunological mechanism (characterized by barrier dysfunction). When dealing with AD, it is essential to identify the predominant mechanism in each case and to provide appropriate and adequate treatment through early intervention. Early intervention includes prevention of sensitization with allergens (primary prevention) and prevention of exacerbation of AD through early and appropriate treatment (secondary prevention). Provided early there is active early intervention, it should be possible to lower the recently increasing prevalence of allergic diseases. Furthermore, if appropriate measures are taken to prevent eruption from following a severe course and to keep the condition in remission, these measures will contribute to improving the QOL of individual patients with AD.

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