Positive atopy patch test reaction to Malassezia furfur in atopic dermatitis correlates with a T helper 2-like peripheral blood mononuclear cells response

The yeast Malassezia furfur belongs to the normal cutaneous flora, but is also a triggering allergen that can contribute to atopic dermatitis. To illuminate the effect of circulating allergen-specific T cells in atopic dermatitis, the peripheral mononuclear cell response was correlated with the in vivo skin prick test and atopy patch test reactivity to M. furfur. None of 16 healthy controls showed any positive in vivo reaction. The 40 atopic dermatitis patients, of whom 18 had serum IgE reactivity to M. furfur, were subdivided according to their in vivo reaction to M. furfur extract into three groups: skin prick test positive/atopy patch test positive (n = 12), skin prick test positive/atopy patch test negative (n = 12), and skin prick test negative/atopy patch test negative (n = 16). The skin prick test positive/atopy patch test positive and the skin prick test positive/atopy patch test negative groups had a significantly higher peripheral mononuclear cell stimulation index than the healthy controls. Interestingly, the stimulation index values in the skin prick test positive/atopy patch test positive group were significantly higher than in the skin prick test positive/atopy patch test negative group. In the M. furfur skin prick test positive atopic dermatitis patients (n = 24) a correlation was found between stimulation index and the M. furfur atopy patch test reactions, but not between stimulation index and M. furfur-specific serum IgE levels. Skin prick test positive and/or atopy patch test positive reactions to the recombinant M. furfur allergens rMal f 1, rMal f 5, and rMal f 6 were observed in 7, 14, and 16 of the 40 atopic dermatitis patients, respectively. Further, there was a correlation between production of the T helper 2-related cytokines interleukins 4, 5, and 13 and stimulation index to M. furfur extract, but not between the T helper 1-related interferon-gamma and stimulation index to M. furfur extract. Our data strongly suggest a relationship between circulating specific T cells with a T helper 2-like cytokine profile and positive atopy patch test reactions.     

Selective cloning of allergens from the skin colonizing yeast Malassezia furfur by phage surface display technology.

The yeast Malassezia furfur, also known as Pityrosporum orbiculare (ovale), is part of the normal microflora of the human skin but has also been associated with different skin diseases including atopic dermatitis. More than 50% of atopic dermatitis patients have positive skin test and specific IgE to M. furfur extracts; however, the pathophysiologic role of these IgE-mediated reactions in the development of the disease remains unknown. The yeast is able to produce a wide panel of IgE-binding proteins, variably recognized by sera of individual patients. In order to assess the contribution of individual components to the disease, highly pure allergen preparations are required. We have cloned M. furfur allergens from a cDNA library displayed on the phage surface, sequenced the inserts and produced recombinant proteins in Escherichia coli. Phage displaying IgE-binding proteins were selectively enriched from the library using IgE from a M. furfur-sensitized atopic dermatitis patient as a ligand. We were able to identify five different inserts coding for IgE-binding polypeptides. Three of the sequenced cDNA encode incomplete gene products with molecular masses of 21.3 kDa (MF 7), 14.4 kDa (MF 8), and 9.7 kDa (MF 9), respectively, having no sequence similarity to known proteins. The other two cDNA encode allergens of 18.2 kDa (Mal f 5) and 17.2 kDa (Mal f 6). Mal f 5 shows significant homology to M. furfur allergens Mal f 2, Mal f 3 and an Aspergillus fumigatus allergen Asp f 3. Mal f 6 has significant homology with cyclophilin. All of the recombinant polypeptides were capable of binding serum IgE from atopic dermatitis patients in immunoblotting experiments. The availability of pure recombinant M. furfur allergens will allow the careful investigation of the role of IgE-binding proteins in atopic dermatitis.     

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.     

Head and neck dermatitis: the role of Malassezia furfur, topical steroid use and environmental factors in its causation

The aetiology of head and neck dermatitis (HND), one subgroup of postpubertal atopic dermatitis (AD), is still unclear. The aim of this study was to evaluate the influence on HND of common environmental factors, long-term topical steroid use, and the role of Malassezia furfur infection. Relevant information was obtained from 100 patients with HND attending our dermatology clinic by means of both physical examinations and questionnaires. Corticosteroid-induced vasoconstriction was estimated by visual scoring of laser-Doppler flowmetry. and the following immunological studies were performed: skin prick test, measurement of total IgE, eosinophil cationic protein, and specific IgE antibodies to several fungal antigens including those of M. furfur. The questionnaire revealed that sweating (81%), heat (71%), dryness (70%), psychic stress (67%), and sun exposure (50%) were responsible for aggravation of skin lesions. The vascular response to topical steroid was reduced in HND patients as compared with that of normal healthy controls (P < 0.05). Fifty-four of 80 patients with HND (68%) had anti M. furfur-specific IgE antibodies and 36 of 80 patients (45%) showed positive skin prick tests for M. furfur. The clinical severity and serum total IgE of HND patients were higher in patients with positive response to anti-M. furfur-specific IgE antibodies than in patients with negative response (P < 0.05). These results suggest that HND can be aggravated not only by M. furfur but also by environmental factors such as sweating, heat, dryness, psychic stress and sun exposure. Furthermore, long-term use of topical steroid might be associated with the development of diffuse erythematous lesions with telangiectasia on the head and neck areas.     

Antigenic components of Malassezia species for immunoglobulin E antibodies in sera of patients with atopic dermatitis

Antigenic components of Malassezia furfur, M. globosa, M. restricta, M. slooffiae, and M. sympodialis were studied for immunoglobulin E antibodies in sera of patients with atopic dermatitis (AD). Antigenic components were extracted from Malassezia cells by treatment with beta-mercaptoethanol, referred to as 2-ME extract. CBB staining and lectin blots using Con A, LCA, PHA-E4, PNA or RCA120 showed that the 2-ME extracts contained several species-dependent components that differed quantitatively and qualitatively among the Malassezia species at the protein level. In the Western blot with the 2-ME extracts, of 54 sera of the patients with AD (54 patients), the patients' IgE antibodies most frequently recognized components showing molecular weights of 43-46 kDa for M. slooffiae, 12-22 kDa for M. sympodialis, 35-40 kDa for M. restricta, 45-50 kDa for M. globosa, and of 67-72 kDa for M. furfur, respectively. In the correlative study, in which the total band intensities generated for each extract in Western blot were compared among the Malassezia species, the intensity for M. globosa was well correlated with that for M. sympodialis (r=0.756). In the Western blot inhibition test, the 2-ME extract of M. globosa partially inhibited the reaction of the antigenic components of other Malassezia species with the patient's IgE antibodies. These results indicated that Malassezia species contained both species-specific and common antigenic components at the IgE antibody level.     

IgE antibodies to Malassezia furfur, M. sympodialis and Pityrosporum orbiculare in patients with atopic dermatitis, seborrheic eczema or pityriasis versicolor, and identification of respective allergens

Malassezia yeasts may be a trigger factor for atopic dermatitis. Following the recent reclassification of the genus, the presence of specific IgE antibodies was examined in the sera of patients with atopic dermatitis (n = 223), pityriasis versicolor (n = 83), seborrheic eczema (n = 50) and hymenoptera allergy (n = 39) and in controls without skin diseases (n = 50). In addition to using the commercially available radioallergosorbent test (RAST) for Pityrosporum orbiculare couplings were also made against the reference strains for M. furfur and M. sympodialis. To characterize the specificity and molecular weight of corresponding epitopes identical material was used for production of an immunoblot. Despite high total levels of IgE, controls and patients with pityriasis versicolor showed no specific IgE antibodies. Six patients (12%) with seborrheic eczema were positive while 78 patients (35%) with atopic dermatitis had specific IgE antibodies in higher RAST classes that differed between the Malassezia species. The molecular weights of the main antigens of M. sympodialis and M. furfur were determined to be 15, 22, 30, 37, 40, 58, 79, 92, 99 and 124 kDa and 15, 25, 27, 43, 58, 92, 99 and 107 kDa, respectively. Evaluated according to the location of their disease, patients with head and neck lesions most frequently showed Malassezia-specific IgE antibodies. However, there were differences between the Malassezia species tested, the previously used strain P. orbiculare being assignable to the species M. sympodialis.     

Systemic ketoconazole for yeast allergic patients with atopic dermatitis

BACKGROUND: Adult patients with atopic dermatitis (AD), especially with the head-neck distribution, are often sensitized to the lipophilic yeast Malassezia furfur/Pityrosporum orbiculare, which is considered to contribute to the pathogenesis of the dermatitis. OBJECTIVE: Evaluation of the efficacy of oral ketoconazole on immunological and clinical parameters in yeast allergic adult patients with AD. STUDY DESIGN: Randomized double-blind placebo-controlled study. SUBJECTS: Twenty-nine patients with specific IgE antibodies to M. furfur/P. orbiculare and with elevated serum IgE participated in the investigation. Fifteen subjects were treated with 200 mg ketoconazole daily and 14 received placebo for 3 months. Betamethasone cream was allowed as supplementary therapy and the consumption was registered. The clinical score (SCORAD), total serum IgE and specific IgE antibodies to M. furfur/P. orbiculare, Candida albicans and Dermatophagoides pteronyssinus were monitored at the starting point and by the end of the first and third month. RESULTS: In the actively treated group the levels of specific IgE to M. furfur/P. orbiculare and C. albicans as well as total serum IgE decreased significantly. Sensitization to D. pteronyssinus was not influenced. The clinical score decreased in both groups, and the improvement was correlated to the consumption of topical steroids in the control group but not in the ketoconazole group.     

AhR ligands, malassezin, and indolo[3,2-b]carbazole are selectively produced by Malassezia furfur strains isolated from seborrheic dermatitis

Malassezia yeasts are connected with seborrheic dermatitis (SD) whereas M. furfur pathogenicity is associated with the production of bioactive indoles. In this study, the production of indoles by M. furfur isolates from healthy and diseased skin was compared, the respective HPLC patterns were analyzed, and substances that are preferentially synthesized by strains isolated from SD lesions were isolated and characterized. Malassezin, pityriacitrin, indole-3-carbaldehyde, and indolo[3,2-b]carbazole (ICZ) were isolated by HPLC from extracts of M. furfur grown in L-tryptophan agar, and identified by nuclear magnetic resonance and mass spectroscopy. Of these, ICZ, a potent ligand of the aryl hydrocarbon receptor (AhR), is described for the first time to our knowledge as a M. furfur metabolite. HPLC-photodiode array detection analysis of strain extracts from 7 healthy subjects and 10 SD patients showed that M. furfur isolates from only SD patients consistently produce malassezin and ICZ. This discriminatory production of AhR agonists provides initial evidence for a previously unreported mechanism triggering development of SD and indicates that the variable pathogenicity patterns recorded for M. furfur-associated SD conditions may be attributed to selective production (P<0.001) of measurable bioactive indoles.     

Malassezia furfur in Infantile Seborrheic Dermatitis

Abstract: Malassezia furfur is important in the pathogenesis of a number of dermatologic diseases including seborrheic dermatitis in adults. It has also recently been suggested that M. furfur might be the etiologic agent in infantile seborrheic dermatitis (ISD). We studied the presence of M. furfur in 21 children with the clinical diagnosis of infantile seborrheic dermatitis. Laboratory analyses showed aberrant patterns of essential fatly acids (EFA) in serum characterized by elevated levels of 18:1w9 and 20:2w6. Samples for M. furfur were taken from the foreheads and chests of children with infantile seborrheic dermatitis at the time of diagnosis, directly after treatment to complete healing, and after 1 year with no signs of infantile seborrheic dermatitis. All the patients were treated topically with borage oil containing 25% gammalinolenic acid (GLA). No reduced growth of M. furfur was seen on contact plates prepared with borage oil. The growth of M. furfur seems not to be related to the clinical symptoms in ISD.     

Injection of allergen-antibody complexes is an effective treatment of atopic dermatitis

Atopic dermatitis (AD) can be exacerbated by contact with airborne allergens, amongst which Dermatophagoides pteronyssinus (Dpt) appears to be potentially important. Specific IgE antibodies towards Dpt are often found in AD, and it can therefore be speculated that suppression of the production of anti-Dpt IgE might result in a significant clinical improvement. Complexes of antigen and specific antibodies have been shown to suppress the production of antibody in other systems; we report here the evaluation in an open trial of the capacity of such complexes to improve symptoms of AD. Ten adult patients were enrolled in this study. In addition to satisfying the criteria of AD, they all suffered from a severe disease (more than 20% of the body surface involved) that had been stable for at least the last 2 years. The patients had high titers of total IgE antibodies and specific anti-Dpt antibodies. Allergen-antibody complexes were prepared from Dpt allergens and an excess of autologous specific anti-Dpt antibodies obtained by immunoadsorption. The patients received regular injections of these complexes throughout 1 year, during which clinical parameters of disease intensity, percentage of body surface affected and intensity of pruritus were regularly monitored. A significant clinical improvement was obtained after 3-4 months of therapy and was maintained through the 9th month. After 1 year of treatment, 2 patients were completely free of disease, 4 had residual lesions which continued to improve and 4 patients had a partial recurrence of dermatitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antimicrobial and anti-inflammatory effects of Cecropin A(1-8)-Magainin2(1-12) hybrid peptide analog p5 against Malassezia furfur infection in human keratinocytes

The lipophilic fungus Malassezia furfur (M. furfur) is a commensal microbe associated with several chronic diseases such as pityriasis versicolor, folliculitis, and seborrheic dermatitis. Because M. furfur-related diseases are difficult to treat and require prolonged use of medications, the treatment for M. furfur-related skin diseases is supposed to gain control over M. furfur growth and the inflammation associated with it, as well as to prevent secondary infections. In this study, we investigated the antifungal and anti-inflammatory effects of cecropin A(1-8)-magainin 2(1-12) hybrid peptide analog P5 on M. furfur. The minimal inhibitory concentration of P5 against M. furfur was 0.39?μM, making it 3-4 times more potent than commonly used antifungal agents such as ketoconazole (1.5?μM) or itraconazole (1.14?μM). P5 efficiently inhibited the expression of IL-8 and Toll-like receptor 2 in M. furfur-infected human keratinocytes without eukaryotic cytotoxicity at its fungicidal concentration. Moreover, P5 significantly downregulated NF-κB activation and intracellular calcium fluctuation, which are closely related with enhanced responses of keratinocyte inflammation induced by M. furfur infection. Taken together, these observations suggest P5 may be a potential therapeutic agent for M. furfur-associated human skin diseases because of its distinct antifungal and anti-inflammatory action.     

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.     

Prevalence of atopic dermatitis and serum IgE values in nursery school children in Ishigaki Island, Okinawa, Japan

There have been many studies of the prevalence of atopic dermatitis (AD), but few population-based epidemiologic studies measure the prevalence in Japan among children aged 5 years and younger. We examined the prevalence of AD, serum total IgE levels and specific IgE antibodies to 10 common allergens among children in Ishigaki Island, Okinawa, Japan in 2001. We also obtained information on the predictability of the U.K. Working Party diagnostic questionnaire criteria for AD in this population. Five hundred and sixty five children aged 5 years and younger were enrolled in this study with informed consent from their parents. The questionnaire of the U.K. Working Party diagnostic criteria for AD was translated into Japanese, and the parents completed the questionnaire sheet. Physical examination and blood sampling were done for all children. Thirty-nine out of the 565 (6.9%) children were diagnosed with AD by physical examination. The total and specific IgE levels were significantly higher in the children with AD than in those without AD. High levels of total IgE were found in 33.3% of the children with AD. A specific IgE to one or more allergens was detected in 64.1% of children with AD. However, a substantial population of children without AD also had high levels of total IgE (12.7%) and a specific IgE to one or more allergens (30.2%), and the increment of total and specific IgE levels was significantly associated with age. The percentage of positive answers to the questionnaire of the U.K. Working Party diagnostic criteria for AD was significantly higher in children with AD (59.0%) than in children without AD (5.3%) (P<0.0001). Its specificity was 94.7%. The false negative rate was 41%. In conclusion, the prevalence of AD was relatively low in children in Ishigaki Island. High levels of total IgE were found in only one third of children with AD under 5 years of age. The Japanese translated form of the questionnaire of the U.K. Working Party diagnostic criteria for AD should be refined to improve its sensitivity.     

Susceptibility of Malassezia furfur subgroups to terbinafine

Summary Malassezia furfur , the fungus causing pityriasis versicolor. has been reported to be sensitive to terbinafine in vitro but although topical therapy is effective in the treatment of pityriasis versicolor. oral therapy is not. This phenomenon was investigated by determining the susceptibility to terbinafine of different M. furfur subgroups in vivo (during topical or oral application) and in vitro. All M. furfur subgroups were suppressed (∼ 10-fold) by topical terbinafine. Oral treatment resulted in no significant suppression of cutaneous M. furfur populations with the exception of a single subgroup (A), which was reduced to undetectable levels on the skin of eight of 10 patients receiving oral terbinafine. Isolates of subgroup A were also markedly more susceptible to terbinafine in laboratory tests. The importance of the recognition of distinct subgroups within the cutaneous lipophilic yeasts when evaluating their antifungal susceptibility and their role in disease is discussed.     

Staphylococcus aureus-derived enterotoxins enhance house dust mite-induced patch test reactions in atopic dermatitis

BACKGROUND: Up to 65% of Staphylococcus aureus strains isolated from the skin of patients with atopic dermatitis (AD) produce exotoxins with superantigenic properties that may also act as allergens leading to an induction of exotoxin-specific IgE antibodies. Staphylococcal enterotoxin B (SEB) applied epicutaneously in a concentration of 10 micro g/cm(2), i.e. 200 micro g/ml, under occlusion induces cutaneous inflammation in patients with AD and healthy individuals. METHODS: We performed patch tests in 32 adult patients with AD using different concentrations (i.e. 2-200 micro g/ml) of SEA, SEB and house dust mite (HDM) extract (500 micro g/ml). Furthermore, the respective enterotoxins and HDM extract were applied simultaneously to the same patch test site. Specific IgE levels to SEA, SEB and HDM were measured with the CAP FEIA. RESULTS: The rates of patch test reactions to SEA and SEB increased with rising enterotoxin concentrations. There were no differences in the rates of patch test reactions to SEA and SEB between patients sensitized to the corresponding enterotoxin and non-IgE-sensitized patients. The number of patch test reactions to the mixture of enterotoxin and HDM extract was higher than the number of patch test reactions to either the enterotoxins or HDM extract. We identified 11 patients with AD who reacted neither to the enterotoxins nor to HDM extract, but who showed patch test reactions to the mixture. These reactions were not predicted by the presence of enterotoxin- or HDM-specific IgE. CONCLUSIONS: Colonization with exotoxin-producing S. aureus may influence the outcome of patch tests in patients with AD.     

花斑癣患者血清中抗糠秕马拉色菌IgG、IgM、IgA抗体的检测及其意义

目的：探讨机体体液免疫在花斑癣发病中的作用和意义。方法：以糠秕马拉色菌（Ｍ．ｆｕｒｆｕｒ）整菌（ＷＭＦ）为抗原,用间接酶联免疫吸附试验（ＥＬＩＳＡ）方法,检测６８例花斑癣患者和４１例正常人血清中的抗ＷＭＦ抗体。结果：正常人血清中存在高滴度的抗ＷＭＦ抗体,花斑癣患者血清中抗ＷＭＦＩｇＧ抗体明显低于正常对照组（Ｐ〈０．０１）,男性患者血清中ＩｇＧ抗体低于女性患者（Ｐ〈０．０１）,病程１年以上者血清中特异的ＩｇＧ抗体低于病程不到１年者（Ｐ〈０．０１）。结论：机体血清抗Ｍ．ｆｕｒｆｕｒ抗体可能是人体内天然抗体,且特异的ＩｇＧ抗体具有保护作用。支持花斑癣的发病与免疫缺陷有关。     

Head and neck atopic dermatitis and malassezia-furfur-specific IgE antibodies

BACKGROUND: Atopic dermatitis of the head and neck (HNAD) has been recognized as a separate entity. Malassezia furfur, a lipophilic yeast, is considered to be a pathogenic allergen in this form of atopic dermatitis. OBJECTIVE: The purpose of this study was to determine the level of IgE anti-M.-furfur antibodies and their relation to the severity of the disease. METHODS: IgE anti-M.-furfur antibodies were assayed in 106 patients with HNAD. Controls included 25 patients with non-HNAD, 20 with nonatopic dermatitis and 16 with seborrheic dermatitis (including 4 with AIDS). RESULTS: There was a highly significant correlation between the level of anti-M.-furfur IgE and clinical severity. Furthermore, there was a significant but smaller correlation between total IgE and clinical severity. In patients with HNAD, total IgE was higher amongst men. CONCLUSION: IgE anti-M.-furfur antibodies are a good and specific marker for HNAD. IgE M. furfur levels are strongly correlated with the severity of the disease.     

Late-onset of IgE sensitization to microbial allergens in young children with atopic dermatitis

Background  A significant proportion of young children with atopic dermatitis (AD) is sensitized to microbial allergens, which play a potential role in the pathogenesis of AD inflammation.
Objective  To study the timing of IgE sensitization to microbial allergens including staphylococcal superantigens, Malassezia species and Candida albicans in young children with AD.
Method  Specific IgE antibodies to staphylococcal superantigens, Malassezia species, C. albicans and control inhalant/food allergens were measured in 53 young children with mild to moderate AD. The presence of IgE sensitization relative to age (≥ 3 years vs. < 3 years) was analysed by logistic regressions.
Results  IgE sensitization to the staphylococcal superantigen group, Malassezia species and C. albicans was significantly associated with older age in children with AD [ P  =   0·02, odds ratio (OR) 4·9; P  =   0·02, OR 4·7; and P  =   0·05, OR 4·0, respectively].
Conclusion  IgE sensitization to microbial allergens is associated with an older age group in young children with mild to moderate AD.     

荨麻疹患者特异性IgE及过敏原检测与分析

目的为进一步了解荨麻疹的致病因素及各种因素之间的相互关系。方法采用过敏原体外检测试剂盒、自体血清皮肤试验及斑贴试验等方法对不同类型荨麻疹患者进行血清特异性IgE、自身抗体及接触性过敏原检测。结果116例患者中有84例(72.4%)至少有一项过敏原阳性。至少一项强阳性的16例,强阳性率为13.8%。各种物质的阳性率差异无显著性(P>0.05)。53例自体血清皮肤试验有20例(37.7%)出现阳性反应。有26例同时进行了上述2项试验。14例自体血清皮肤试验阳性的荨麻疹患者血清特异性IgE均无强阳性反应,而12例自体血清皮肤试验阴性的患者中有4例(33.3%)呈强阳性反应(P<0.05)。对21例慢性荨麻疹患者进行斑贴试验,有19例(90.5%)至少对其中一种物质过敏。20种物质中有15项出现阳性,其中重铬酸钾、硫酸镍、橡胶的阳性率达到了38.1%。结论荨麻疹的病因是多方面的,既有可能对外界物质过敏,又有可能存在自身免疫的问题。同一患者可能同时存在2种不同类型的变态反应;接触性过敏原可引起接触性荨麻疹。     

IgE antibodies to Pityrosporum ovale in atopic dermatitis

An enzyme-linked immunosorbent assay (ELISA) was developed to assess serum IgE antibodies directed against Pityrosporum ovale in patients with atopic dermatitis (AD), atopic patients with allergic respiratory disease (ARD: rhinitis or asthma) but without eczema, and in healthy controls. IgE binding to P. ovale extract was demonstrated in 49% (35/72) of AD patients. In contrast, anti-P. ovale IgE was found in only one of 27 atopic controls without eczema; all healthy control sera (n = 17) were negative. Of 37 AD patients tested intracutaneously with P. ovale, 31 showed immediate-type reactivity, and 20 of these 31 patients had anti-P. ovale IgE detectable by ELISA, while sera from the six non-responders were all negative. Levels of anti-P. ovale IgE were highest in AD patients aged 20-30 years. No correlation was found with the severity of AD, but there was a non-significant tendency (P = 0.06) to higher levels in AD patients with concomittant respiratory allergy. Anti-P. ovale IgE was significantly correlated with total serum IgE, with specific IgE against various aeroallergens as measured by RAST, and with levels of anti-Candida albicans IgE, measured with a similar ELISA. Thus, production of IgE antibodies against P. ovale occurs very frequently in AD, and rarely in patients with atopic disease without skin involvement.