Contact and aeroallergens in adulthood atopic dermatitis

Background Atopic dermatitis (AD) is a clinically well‐defined, chronic‐intermittant, genetically predisposed skin disease. The increasing number of adult cases observed in the last years has turned the attention to ascertaining factors eliciting skin symptoms. Studies have revealed numerous environmental components (e.g. contact and aeroallergens) that may play an important role in sustaining the symptoms. The aim of the study was to search for contact allergens and aeroallergens triggering the skin disease in adult AD patients. Methods Patients over 18 years from our Atopy Outpatient Department were included in the study. Diagnosis of AD was based on the clinical criteria of Hanifin and Rajka. The distribution of skin symptoms was characteristic for adult AD: hands, shoulders, neck, flexures, face and eyelids. The extremities and the trunk were less involved. The potentially provoking contact and aeroallergens were examined in symptom and drug‐free period with atopy patch and epicutaneous tests (APT, ET), which were supplemented by in vitro allergy and Prick tests. The relevance of sensibilization was evaluated by the comparison of in vivo and in vitro test results, medical history and skin symptoms. Results A total number of 34 cases of adult AD (23 women and 11 men) were studied. Four of them were classified into the intrinsic group (IG; 12%), and 30 were classified into the extrinsic group (EG; 88%). The incidence of contact sensitization to environmental allergens was remarkable: 13 of the EG, 1 of the IG (14 of 34, 41%). In the IG, a late thiomersal positivity was detected without clinical relevance. In the EG, epicutaneous standard series late positivity was seen in 13 patients, in four of them with multiple sensitivity. The allergens causing positivity were nickel (6 of 13), thiomersal (3 of 13), mercury‐amidochlorate (3 of 13), mercury‐chloride (2 of 13), iodine chlorhyrdoxyquin (1 of 13), lanalcolum (1 of 13) and fragrance mix (1 of 13). Among the detected allergens, the following were relevant: lanalcolum (1 of 13: cosmetics), fragrance mix (1 of 13: cosmetics), nickel (1 of 13: metal objects), thiomersal (1 of 13: eyedrops). No immediate response was seen with APT. Relevant late positivity was shown with APT test in one patient in the IG (1 of 4) to Dermatophagoides pteronyssinus. We observed late positivity in 18 patients in the EG (18 of 30). Among the detected allergens, the following were clinically relevant: D. pteronyssinus and/or Dermatophagoides farinae (15 of 18), cat epithel (4 of 18), timothy pollen (1 of 18) and dog epithel (1 of 18). Furthermore, we examined the relevance of APT, specific immunoglobulin E (IgE) tests and Prick tests. We observed multiplex positivity by specific IgE tests, APT and Prick tests in 14 patients in EG. Sensitization to D. pteronyssinus and/or D. farinae (11 of 14) cat epithel (4 of 14), dog epithel (1 of 14) and timothy pollen (1 of 14) proved to be clinically relevant with the atopic skin symptoms and medical history. Conclusion The proportion of contact sensitization to environmental allergens in the 34 adult atopic patients was remarkable (14 of 34, 41%). Out of the verified contact allergens, nickel, fragrance mix, thiomersal and lanalcolum proved to be relevant. House dust mite and cat epithel proved to be the most common relevant aeroallergens. D. pteronyssinus and D. farinae sensibilization was high, particularly in patients with severe skin symptoms on the face, eyelids and hands. Pollens should be considered in patients with seasonal relapse of AD. Sensitization to animal epithel was usually indicated by the flare‐up of skin symptoms upon contact with animals. The relevance of the eliciting effects of sensitization could easily be supported in most cases by the medical history and the distribution of skin symptoms. In some adult AD patients with long‐lasting AD, the relevance of triggering factors is hard to determine.     

Sweat mechanisms and dysfunctions in atopic dermatitis

Skin barrier dysfunction is inherent to atopic dermatitis (AD), causing dryness, irritation, and increased permeability to irritants, allergens and pathogens. Eccrine sweat functions as part of the skin’s protective barrier. Variations in sweat responses have been observed in patients with AD, and altered sweat composition and dynamics are under-recognized as important factors in the disease cycle. This review discusses the role that sweat plays in the pathogenesis of AD, examines evidence on abnormal sweat composition, secretion, and neuro-immune responses to sweat in atopic skin, and highlights the value of sweat management.     

Food allergy in atopic dermatitis

Food allergy predominantly affects children rather than adult patients with atopic dermatitis (AD). Early sensitization to foods has been found to be significantly associated with AD. Three different patterns of clinical reactions to food allergens in AD patients exist: i. immediate-type reaction, ii. isolated late-type reaction, iii. combined reaction (i.?+?ii.). While in children allergens from cow's milk, hen's egg, soy, wheat, fish, peanut or tree nuts are mostly responsible for allergic reactions, birch-pollen related food allergens seem to play a major role in adolescent and adults with AD in Central and Northern Europe. Defects of the epidermal barrier function seem to facilitate the development of sensitization to allergens following epicutaneous exposure. The relevance of defects of the gut barrier as well as genetic characteristics associated with an increased risk for food allergy remain to be further investigated. Numerous studies focus on prevention strategies which include breast-feeding or feeding with hydrolyzed milk substitute formula during the first 4 months of life.     

Silk fabrics in the management of atopic dermatitis

Many factors may worsen atopic dermatitis (AD) including sweating, skin infections, food, inhalant allergens, climatic conditions, stress, and chemical or physical irritants. Especially in children, clothing can be an effective barrier against flare-inducing factors and persistent scratching, allowing more rapid improvement of the eczematous lesions. On the contrary, some fabrics used for clothing may exacerbate skin conditions due to their rough fibers, such as wool and nylon. Conventional silk has smooth fibers that are generally woven for textiles in the manufacturing of clothes, but this material is not particularly useful in the management of children with AD since it reduces transpiration and may cause discomfort. Herein, we evaluate the data concerning a special silk fabric (MICROAIR DermaSilk?) shown to be suitable for patients with AD. The unique properties of this knitted silk allow the skin to breathe and lack irritative potential. Moreover, this fabric is treated with a water-resistant antimicrobial finish known as AEGIS AEM 5772/5. This novel knitted silk fabric appears to be useful in managing children with AD due to its non-irritating and antibacterial features. Additionally, a synthetic silk-like fabric (DermaTherapy?) has received US FDA clearance as a Class I medical device and is commercially available as bedding; their use by AD patients has shown interesting results.     

Specific IgE to Staphylococcus aureus in patients with atopic dermatitis

It is a well-known feature of atopic dermatitis (AD) that the patient's skin is heavily colonized by Staphylococcus aureus. S. aureus-derived antigens may be important triggers of the immune response and may significantly contribute to the genesis of the cutaneous pathology of AD. Therefore, serum samples of 52 patients with AD, all of whom had signs of moderate to severe disease activity, were tested for antistaphylococcal IgE antibodies with RAST discs coupled to antigens derived from Wood 46 strain. Total IgE concentrations and specific IgE to nine different common allergens were also determined. Only 2 patients showed significant levels of specific IgE antibodies to S. aureus (RAST class greater than or equal to 2). Both these patients were found to have high total IgE and significant levels of specific IgE to all nine common allergens tested. One of the patients had marked eosinophilia. We conclude that the presence of specific IgE to S. aureus is not correlated with the disease activity in AD. Specific antistaphylococcal IgE does not represent an important diagnostic feature in AD, but may be of importance for the detection of subgroups within patients affected by AD.     

Atopy patch test reactions to Malassezia allergens differentiate subgroups of atopic dermatitis patients

BACKGROUND: The yeast Malassezia is considered to be one of the factors that can contribute to atopic dermatitis (AD). OBJECTIVES: To investigate the reactivity to Malassezia allergens, measured as specific serum IgE, positive skin prick test and positive atopy patch test (APT), in adult patients with AD. METHODS: In total, 132 adult patients with AD, 14 with seborrhoeic dermatitis (SD) and 33 healthy controls were investigated for their reactions to M. sympodialis extract and three recombinant Malassezia allergens (rMal s 1, rMal s 5 and rMal s 6). RESULTS: Sixty-seven per cent of the AD patients, but only one of the SD patients and none of the healthy controls, showed a positive reaction to at least one of the Malassezia allergens (extract and/or recombinant allergens) in at least one of the tests. The levels of M. sympodialis-specific IgE in serum correlated with the total serum IgE levels. Elevated serum levels of M. sympodialis-specific IgE were found in 55% and positive APT reactions in 41% of the AD patients with head and neck dermatitis. A relatively high proportion of patients without head and neck dermatitis and patients with low total serum IgE levels had a positive APT for M. sympodialis, despite lower proportions of individuals with M. sympodialis-specific IgE among these groups of patients. CONCLUSIONS: These results support that Malassezia can play a role in eliciting and maintaining eczema in patients with AD. The addition of an APT to the test battery used in this study reveals a previously overlooked impact of Malassezia hypersensitivity in certain subgroups of AD patients.     

Adhesion molecule profiles in atopic dermatitis vs. allergic contact dermatitis: pharmacological modulation by cetirizine

BACKGROUND: Experimental data suggest that there is an imbalance between Th1 and Th2 cells in atopic dermatitis (AD) skin compared to allergic contact dermatitis (ACD). This imbalance (Th2 and Th1 predominance, respectively) implies the production of different cytokines in these two conditions leading to different expression of adhesion molecules on skin endothelial cells. OBJECTIVE: The expression of VCAM-1 (IL-4/Th2-dependent) and ICAM-1 (INF-gamma/IL-1) on dermal vessels was compared in six patients with AD and six patients with ACD. The effect of cetirizine, a highly selective H1-receptor antagonist on the expressions was studied. METHODS: Six patients with AD were challenged with Dermatophagoides pteronyssimus (DPT patch tests applied to clinically normal skin) and six patients with ACD challenged in the same way with allergens of the European standard series. Skin biopsies at challenged sites were performed before and 6, 24 and 48 h after challenge. The experiment was carried out under double-blind cross-over conditions during a 4-day treatment with a placebo and cetirizine. RESULTS: In AD patients, the scores for both VCAM-1 and ICAM-1 were high before and after challenge. In ACD patients, the ICAM-1 score was high at each experimental time, but the VCAM-1 score, which was significantly lower before challenge, increased at 6, 24 and 48 h after challenge. The administration of cetirizine significantly reduced the VCAM-1 expression in AD patients at each experimental time. CONCLUSION: It is concluded that the increased VCAM-1 expression in AD patients compared to ACD may reflect greater IL-4 and/or IL-13 production in situ. The study also confirms the existence of a modulating effect of cetirizine in vivo on adhesion molecule expression.     

Mast cell chymase is increased in chronic atopic dermatitis but not in psoriasis

Mast cell chymase is a chymotrypsin-like serine proteinase primarily stored in secretory mast cell granules. Mast cell chymase has various effects on angiotensin, metalloproteases, lipoproteins, procollagen, neuropeptides and cytokines. Recent studies have demonstrated that chymase inhibitors inhibit skin inflammation. In this study we sought to determine the role of mast cell chymase in atopic dermatitis (AD) in comparison with its role in psoriasis and normal skin. Skin biopsy specimens were obtained from non-lesional and lesional skin of patients with chronic AD and psoriasis and from normal skin of non-atopic and non-psoriatic controls. The number of mast cells containing chymase was determined by immunohistochemistry using a chymase-specific monoclonal antibody. A significantly (P<0.05) enhanced number of chymase-positive cells was found in lesional AD skin as compared to normal skin as well as to lesional and non-lesional skin of patients with psoriasis. A significant (P<0.05) increase in the number of chymase-positive cells was also found in non-lesional AD skin in comparison to psoriasis. An enhanced, albeit not statistically significant difference was noted in non-lesional AD skin as compared to normal skin. In conclusion, these results suggest that mast cell chymase may play an integral part in eliciting and maintaining cutaneous inflammation in AD but not in psoriasis. The increased proteinase activity of mast cell chymase may also be involved in promoting a skin barrier defect in AD, which subsequently enhances the skins permeability to allergens and microbes and thereby aggravates the eczema.     

Isolation of α-toxin-producing Staphylococcus aureus from the skin of highly sensitized adult patients with severe atopic dermatitis

Background  Staphylococcus aureus (S. aureus) is a well-known trigger factor of atopic dermatitis (AD). Besides staphylococcal superantigens, α-toxin may influence cutaneous inflammation via induction of T-cell proliferation and cytokine secretion.
Objectives  To investigate the association between sensitization to inhalant allergens and skin colonization with α-toxin-producing S. aureus in AD.
Patients and methods  We investigated 127 patients with AD, aged 14–65 years, who were on standard anti-inflammatory and antiseptic treatment before investigation. We evaluated skin colonization, medical history, severity of AD and sensitization to inhalant allergens.
Results  Forty-eight of 127 patients were colonized with S. aureus , suffered from more severe AD, had asthma more often and showed higher sensitization levels to inhalant allergens. Thirty of 48 patients with S. aureus skin-colonizing strains produced α-toxin and had higher total IgE and specific IgE to birch pollen and timothy grass pollen.
Conclusions  Under topical treatment with antiseptic and anti-inflammatory agents the colonization of lesional skin with S. aureus was clearly lower than commonly found in untreated patients with AD. Colonization with S. aureus was associated with a higher severity of AD, higher degree of sensitization, and a higher frequency of asthma. The proportion of patients whose skin was colonized with α-toxin-producing S. aureus was higher than expected from a former study. Cutaneous colonization with α-toxin-producing S. aureus was associated with a higher sensitization level to birch pollen allergen in AD. This may point to a higher susceptibility of patients with higher T-helper 2 polarization towards α-toxin-producing S. aureus .     

Managing atopic dermatitis

"Itchy" rashes occurring in patients (usually an infant or child) with a personal and/or family history of itching, sneezing, and/or wheezing should be considered part of the spectrum of skin problems labeled "atopic dermatitis" (AD). Multiple factors influence AD, and effective management requires that none be overlooked. The complicated nature of treatment means parents and family members require repeated reinforcement and education, particularly in avoiding "triggers of itch;" and use of medications. When all the aspects of AD are adequately addressed, more than 90% of patients with AD can be effectively managed.     

变应原特异性免疫治疗特应性皮炎的进展

特应性皮炎作为一种过敏性皮肤病,变应原在其发病过程中起重要作用,变应原特异性免疫治疗通过多次、小剂量接触变应原,诱导机体产生免疫耐受,针对病因治疗是改变过敏性疾病进程唯一有效的方法.目前变应原特异性免疫治疗已广泛应用于过敏性疾病,但由于对治疗方法认识的不足及缺乏大样本临床数据的肯定,对特应性皮炎的治疗仍有争议,较为接受的是皮下注射和舌下含服.近几年研究发现,单克隆抗体联合免疫治疗,可提高免疫治疗的安全性,新的给药途径如淋巴结注射免疫治疗和经皮免疫治疗,以及新的治疗方案(快速变应原特异性免疫治疗和集群变应原特异性免疫治疗)可有效治疗特应性皮炎,且不增加不良反应发生率,而建立在食物过敏基础上的变应原特异性免疫治疗尚有争议.     

Impaired sphingomyelinase activity and epidermal differentiation in atopic dermatitis

A defective permeability barrier leads to the penetration of environmental allergens into the skin and initiates immunological reactions and inflammation crucially involved in the pathogenesis of atopic dermatitis (AD). Decreased stratum corneum ceramide content may cause the defect in permeability barrier function consistently found in AD. Acid and neutral sphingomyelinase (A- and N-SMase) generate ceramides with structural and signal transduction functions in epidermal proliferation and differentiation. We determined epidermal SMase activities, DNA synthesis, involucrin, loricrin, filaggrin, and keratin expression in lesional and non-lesional skin of AD patients. We found decreased epidermal A-SMase activity in lesional and non-lesional skin, correlating with reduced stratum corneum ceramide content and disturbed barrier function. N-SMase activity was reduced in non-lesional skin and more significantly reduced in lesional skin, correlating with impaired expression of cornified envelope proteins and keratins, important for skin barrier function. Changes in involucrin, loricrin, filaggrin, keratin K 5 (basal) and K 16 (proliferation associated) were noticed in non-lesional and lesional skin, whereas changes in K 10 (suprabasal), K 6 (proliferation associated), and K 17 (inflammation associated) were found only in lesional skin. In summary, reduction in SMase-generating ceramides and impaired differentiation are involved in the defective barrier function found in AD.     

Frequency of atopic dermatitis and relevance of food allergy in adults in Germany

Many factors may aggravate atopic dermatitis. The aim of this study was to determine the frequency of atopic dermatitis in an unselected population sample and to evaluate the role of food allergy. Patients with atopic dermatitis were recruited from the population in Berlin, Germany, using a postal questionnaire. Skin prick tests for allergens were performed, followed by food challenges. A total of 1739 questionnaires was returned. In all, 23.5% of patients stated that they had atopic dermatitis, and 146 persons (8.4%) fulfilled our atopic dermatitis criteria after a detailed telephone interview. Of these, 111 were examined, and 28 (1.6%) were identified as currently suffering from atopic dermatitis. Twenty-seven patients were further evaluated: 9/27 were found to be skin prick test negative, 19/27 were skin prick test positive either to pollen and/or food allergens. Nine of 27 were challenged with the suspected food allergen: 1/9 showed a worsening of the eczema, 3/9 had oral symptoms, and 5/9 were negative. In conclusion, only 20% of adults with a positive history of atopic dermatitis show active eczema lesions at a given time point. The data indicate that most individuals with atopic dermatitis were sensitized against pollen allergens and according to that, pollen-associated food allergens. A non-selected AD patient cohort does not frequently suffer from clinically relevant pollen-associated food allergy.     

The utility of patch testing children with atopic dermatitis

Allergic contact dermatitis (ACD) is more frequent in the pediatric population and in children with atopic dermatitis (AD) than has hitherto been appreciated. Patch testing, which is mediated by different immune mechanisms than prick skin testing, is both safe and diagnostically useful for individuals with AD. It may help to identify exacerbating allergies, e.g., constituents of topical treatments in refractory AD and to formulate treatment plans that feature preventive avoidance of the offending allergens.     

The diagnostic value of atopy patch testing and prick testing in atopic dermatitis: facts and controversies

We conducted a systematic Medline search of the literature (1998-2008) on the criteria for performing the skin prick test and atopy patch testing (APT) to determine their utility in atopic dermatitis (AD). The skin prick, scratch, and skin patch tests are performed to identify which allergen is causing eczematous skin symptoms in patients with AD, or sneezing, nasal congestion, itchy eyes, wheezing, skin rash, and swelling. Many allergens in foods, drugs, and environmental substances (eg, ragweed and fungus), as well as contact allergens, can elicit eczematous skin reactions after epicutaneous application. Because no gold standard exists for aeroallergen provocation in AD, the APT is currently used to evaluate allergen without comparison with another accurate and reliable method. The APT is presumed to reflect delayed-phase clinical reactions. Even with delayed onset of symptoms (more than 2 hours after food ingestion), APT findings were not consistent among AD children. The APT could be used in children with gastrointestinal reactions to foods as well as AD. After standardization, the APT may provide further diagnostic information in addition to the skin prick test and serum immunoglobulin E values and may be able to evaluate the actual clinical relevance of immunoglobulin E-mediated sensitizations for eczematous lesions. The European APT model used with standardization of allergen concentration and vehicle may provide an important diagnostic tool to select patients for avoidance and for procedures of allergen-specific immunotherapy, but the clinical relevance of positive APT reactions awaits standardized provocation and avoidance testing.     

Phenotypes of atopic dermatitis

Atopic dermatitis (AD) is a common disease affecting both children and adults. AD develops from a complex interplay between environmental, genetic, immunologic and biochemical factors. Genetic factors predispose atopic subjects to mount exaggerated Th2 responses and to a poorly efficient epidermal barrier, which may be sufficient to initiate inflammation in the skin and may favor allergic sensitization. Thus AD can present with different clinical pheno‐types. AD is classically distinguished into an intrinsic and extrinsic form, which are clinically identical but the former lacks high level specific IgE and is not associated with respiratory atopy. Although in many cases AD presents with monotonous eczematous lesions on the face, neck and skin folds, it may also present with other features. Very common is nummular eczema, which in many instances may be the dominant expression of AD. In other patients, AD affects limited areas (periorificial eczema, nipple eczema, cheilitis, hand eczema) or its main presentation is with excoriated papules and nodules (atopic prurigo). In conclusion, AD is a multifaceted disease affecting patients with epidermal barrier dysfunction and dry and sensitive skin. The recognition of the less common AD phenotypes is essential for proper patient management.     

The natural history of sensitizations to food and aeroallergens in atopic dermatitis: a 4-year follow-Up

The natural history of atopic dermatitis (AD) is variable. Generally the dermatitis disappears during the first years of life, but it is often followed by the appearance of allergic respiratory diseases (ARDs). Our aim was to establish the risk factors for developing an ARD in children with AD. We followed up for 4 years 78 children (51 boys, 27 girls) with mild (26%), moderate (48%), and severe (26%) AD (clinical score proposed by Rajka and Langeland). In all the patients IgE serum levels were checked and skin prick tests (SPTs) were performed at the first examination. The SPTs were repeated in 68 children at the end of the study. The children with severe AD had significantly higher IgE serum levels than those with mild or moderate AD. SPTs at the first observation were positive in 47% of cases, mostly in patients with severe AD, with a prevalence of food allergens, particularly in younger patients. At the second observation, SPTs were positive in 65% of cases, including 100% of children with severe AD. Inhalants were the most common allergens. An ARD appeared in 38% of all patients: in 75% of those with severe AD and in 54% of those with a positive first SPT. Allergic screening should be carried out at an early age, especially in severe AD, since SPT positivity to food allergens, associated with severe clinical AD symptoms and a high IgE serum level, identifies those children ages 0-3 years at high risk of development of ARD.     

Interactions between FLG mutations and allergens in atopic dermatitis

Filaggrin gene (FLG) mutations and sensitization in patients with atopic dermatitis (AD) have been well documented. However, whether an interaction exists between these mutations and specific sensitization in AD patients is still unknown. The aim of the study was to explore the interaction between FLG mutations and specific sensitization in AD patients. A total of 249 AD outpatients were recruited in the current study. Skin prick tests were conducted to assess the patient??s sensitization to specific allergens. FLG mutations were analyzed through comprehensive sequencing. Logistic regression analyses were conducted to determine the interactions between FLG mutations and sensitization present. The mean age of the patients was 3.5?years, and the mean age of onset of AD was 9.6?months. The mean SCORAD of the patients was 25.8. Fourteen types of mutations were identified in the FLG of 64 patients. A total of 24 (9.6?%) and 29 (11.6?%) cases were mutated with 3321delA and K4671X, respectively. Sensitization to at least one type of allergen was detected in 118 patients (47.4?%). Logistic regression analyses showed that FLG mutations presented an interaction with sensitization to peanut and did not interact with the other detected allergens among AD patients. Sensitization to peanut allergens would have an interaction with the mutation of K4671X and the combined mutations in FLG in patients with atopic dermatitis. However, sensitization to the other common allergens might not interact with FLG mutations in the development of atopic dermatitis.     

Mast cells and IgE in intestinal mucosa in adult atopic dermatitis patients

Duodenal biopsies from 29 adult atopic dermatitis (AD) patients with multiple positive skin prick test reactions were examined and the results compared with biopsies from 13 non-atopic controls. The duodenal mucosa showed mild inflammatory changes in six out of the 29 patients, but was normal in all the controls. Numerous anti-IgE positive cells, increasing with the severity of AD, were found in the duodenal mucosa in 25 of the 29 AD patients compared with few sporadic positive cells seen in only two out of 13 controls (P less than 0.001). The total serum IgE level showed a significant positive correlation with the number of anti-IgE stained cells in the mucosa (P less than 0.05). No significant differences were found in the total number of toluidine blue stained cells or cells immunoreactive for histamine between patients and controls. However, AD patients who had high numbers of anti-IgE positive cells often had decreased numbers of histamine immunoreactive cells in the mucosa suggesting mast cell degranulation. These findings provide further evidence that also in adult AD patients the gastrointestinal tract may serve as a portal of entry for allergens which may lead to exacerbation of AD.     

Polymorphisms within the C3 gene are associated with specific IgE levels to common allergens and super-antigens among atopic dermatitis patients

Abstract:  Atopic dermatitis (AD) is a chronic inflammatory skin disease. Twin and family studies suggest a strong genetic component of the disease. The keratinocytes secrete high amounts of C3 after stimulation with pro-inflammatory cytokines, which may play a functional role in skin inflammation. In this study, we genotyped four different single nucleotide polymorphisms (SNPs) by melting curve analysis using sequence specific hybridization probes in a well-characterized cohort of AD patients. Among four SNPs within C3 gene, higher frequencies of rs10410674 (23.5% vs 12.2%) and rs366510 (13.8% vs 6.5%) were observed in AD patients as compared with control group. None of the tested polymorphisms showed significant association with the risk of the disease phenotype. Analysis of rs10402876 SNP revealed its association with less severe AD disease expression (low SCORAD). Total serum IgE levels were not different among AD patients having any of the four SNPs. However, we observed significantly less serum-specific IgE levels to common allergens ( Dermatophagoides pteronyssinus and birch pollens) and Staphylococcal enterotoxin B in AD patients having rs366510 SNP. Thus, associations of polymorphism within C3 gene with less severe AD disease expression and a weaker sensitization to common allergens suggest the role of these SNPs in the development of AD.