Patch-test reaction patterns in patients with a predisposition to atopic dermatitis

Patients with a predisposition to atopic dermatitis often need to be patch tested in order to detect possible contact sensitization. However, it is unknown whether immunologic or other peculiarities of atopic skin are related to altered patch-test reaction patterns. Our study was aimed at answering this question, because patch-test reaction patterns are of considerable practical importance in the reading and interpretation of patch tests. Therefore, we compared patterns of patch-test reactions in patients with a predisposition to atopic dermatitis and in control patients matched for sex, age, reason for testing and test centre. Patch-test results from 9 centres (2322 patients with a disposition to atopic dermatitis and 2126 matched controls) were evaluated retrospectively. All patients were tested with nickel sulfate, fragrance mix, potassium dichromate, lanolin alcohol, formaldehyde and mercury ammonium chloride. Patch tests applied for 1 day with readings on days 1, 2 and 3 were evaluated in order to cover the early phase of the reactions. Not unexpectedly, we found that, compared to the matched controls, patients with a predisposition to atopic dermatitis tended to have more doubtful and irritant reactions on day 1. As a new observation, it turned out that they had less reactions of crescendo pattern and more strong reactions on day 3. All these differences were slight/insignificant. A higher skin irritability in patients with a predisposition to atopic dermatitis is a likely explanation. In conclusion, standard methods for patch testing can be applied in patients with a predisposition to atopic dermatitis, but minor differences in reaction patterns should be considered.     

6th Dermatopathology Self-Assessment Workshop

Results of patch tests performed in 15.553 patients by IS dermatological department (members of the German Contact Dermatitis Research Group) and recorded by the Information Network of Departments of Dermatology (IVDK) were analysed by comparing recently defined reaction indices (RIs). The RIs studied were calculated from the numbers of allergic (a), questionable (q), and irritant (i) reactions (RI = (a-q-i/(a+q+l)), which were obtained using 13 European standard allergens. RIs were calculated for all patients and for separate subgroups defined by age, sex, history of atopic dermatitis time of allergen exposure (1 versus 2 days), and lime of patch test reading (2 or 3 days after allergen application), Higher RIs were consistently obtained when patch tests were applied for 1 day, as compared to 2 days. Readings at 3 days after allergen application resulted in higher RIs than readings after 2 days. In contrast, sex, age, and history of atopic dermatitis of patients were not found to have LI consistent influence on the RIs. We suggest that reading after 3 days should be obligatory, and that allergen exposure for 1 day instead of 2 days might make patch test evaluation easier. These suggestions need to be substantiated by data on clinical relevance.     

Atopy patch test reaction to airborne allergens in the diagnosis of atopic dermatitis

The aim of the study was to evaluate the possible use of atopy patch test in the diagnosis of atopic dermatitis and to characterize an optimal standardized system for atopy patch test in terms of allergen concentrations and time of allergen exposure. The study included 36 patients with atopic dermatitis and IgE-mediated airborne allergy. Patients presented positive results of skin prick tests and serum antigen specific IgE against house dust mite allergens and/or selected grass pollen allergens. Control groups consisted either of patients with allergic rhinitis (control group 1) or healthy volunteers with no signs or symptoms of atopy (control group 2). Allergologic diagnostic workup consisted of skin prick test, serum antigen specific IgE and total IgE evaluation, atopy patch test with selected airborne allergens of different concentrations (0.1xSPT, 1xSPT and 10xSPT), time of allergen exposure (8, 24 and 48 h), and readings of the results (8, 24, 48 and 72 h). Positive results of atopy patch test with airborne allergens were obtained in 47.2% of atopic dermatitis patients and none of control subjects. Contact reaction itself and the intensity of reaction were demonstrated to correlate with allergen concentration and time of allergen exposure on atopy patch test. The dose and time response analysis showed the optimal concentration of allergens for atopy patch test to be 10xSPT, 500000 SBE/ml, and optimal evaluation time 24 and 48 h of allergen application. There was no correlation between atopy patch test results and mean serum concentrations of total or antigen specific IgE. Atopy patch test results did not correlate with localization of skin lesions, severity and extensiveness of skin inflammation. A significantly higher contact reactivity to airborne allergens was recorded in the group of atopic dermatitis patients with polyvalent allergy in comparison with atopic dermatitis patients allergic to only one aeroallergen. It is concluded that atopy patch test is the only provocation test currently available with clinical relevance for contact IgE-mediated sensitization in atopic dermatitis patients. Using petrolatum as a vehicle, allergen concentration of 500000 SBE/ml and evaluation time of 24 and 48 h of allergen application may lead to improved atopy patch test results.     

Patch testing with 20% Dermatophagoides pteronyssinus/farinae (Chemotechnique) antigen.

BACKGROUND: Patch testing with dust mite antigens might identify mite-sensitive individuals, particularly those with atopic dermatitis who can benefit from avoidance measures. Currently available dust mite allergens have not been well studied. OBJECTIVE: To determine the proper dilution of 20% Dermatophagoides pteronyssinus/farinae mix antigen (Chemotechnique, Malmo, Sweden) for use in closed patch testing. METHODS: Eighteen nonatopic, healthy control subjects were patch-tested to the 20% concentration, yielding 15 (83%) positive reactions, most showing a decrescendo or persistent pattern suggesting an inordinately high number of false positive reactions. Dilutions of 1.25% to 0.1% in white petrolatum were used in patch testing 8 atopic dermatitis and 11 respiratory atopy patients, and 12 nonatopic controls. RESULTS: Positive reaction rates to the 0.25% and 0.1% concentrations, respectively, were 87.5% and 62.5% for atopic dermatitis, 54% and 18% for respiratory atopy, and 33% and 8% for healthy controls. Using Fisher's exact test, the 0.1% dilution was shown to significantly differentiate rates of positivity among the 3 groups, particularly between atopic dermatitis subjects and healthy controls. CONCLUSION: We find that a 0.1% dilution of 20% D. pteronyssinus/farinae mix antigen (Chemotechnique) to be useful in identifying mite-allergic individuals with atopic dermatitis.     

Atopy patch tests in young adult patients with atopic dermatitis and controls: dose-response relationship,objective reading,reproducibility and clinical interpretation

The clinical interpretation and reproducibility of atopy patch tests was studied in 23 selected young adult patients with atopic dermatitis and 25 healthy controls using standard inhalant allergens. Non-invasive measurements were used for objective assessment of test reactions and the participants were retested after 6 weeks. Ten of 19 (53%) evaluable patients with atopic dermatitis had at least one positive atopy patch test. However, there was no clear clinical relevance of the atopy patch test results when related to patient history and distribution of dermatitis. Reproducible and dose-dependent results were obtained with Dermatophagoides pteronyssinus, grass and cat with a reproducibility rate of 0.69 to 0.81 in patients and 0.60-0.96 in controls. A unique finding was a significant positive correlation between a positive atopy patch test, allergen dose and increase in transepidermal water loss and erythema, while measurement of capacitance did not distinguish between positive and negative reactions. The results of the present study do not support the routine use of atopy patch tests in the evaluation of adult patients with atopic dermatitis.     

The frequency of contact allergy in atopic patients with dermatitis

A prospective study was performed to establish the frequency of contact allergy in atopic patients presenting with dermatitis, compared with non-atopics suffering from dermatitis. During 1987-1988, all new patients aged 15 years or older, who consulted us for dermatitis, were investigated. They were patch tested with the European standard series, methyl(chloro)isothiazolinone and other relevant allergens. In addition, they were prick tested with 24 inhalant and 11 food allergens. Patients having at least 2 positive prick tests, and patients with 1 positive prick test and a (family) history of atopic diseases were defined as atopics, as were those who presented with classic atopic dermatitis but with negative prick tests. 499 patients were evaluated: 159 men and 340 women. 214 patients (43%) were atopic, the other 285 (57%) were non-atopic. In the atopic group, 79 persons (37%) had at least 1 positive patch test reaction. In the group of non-atopics, 149 patients (52%) had contact allergies. The difference is statistically significant (chi 2; p less than 0.05). It is concluded that adult atopics seen in dermatological practice who present with dermatitis are less frequently contact sensitized than such patients who are non-atopic. Nevertheless, a yield of nearly 40% positive patch test reactions in this group still makes routine patch testing necessary.     

Contact allergy to Dermatophagoides in atopic dermatitis patients and healthy subjects

To compare different house-dust-mite-derived allergenic materials and to correlate the presence of IgE LO Dermatophagoides with patch test results, 313 atopic dermatitis (AD) patients and 100 healthy volunteers (HV) underwent patch tests with: Dermatophagoides Pteronyssimus (DPT) lyophilized purified alpha fraction in buffered saline/glycerol 50% and or in petrolatum (Bayropharm); 540% DPT and 50% Dermatophagoides farinae (DF) whole bodies in petrolatum and petrolatum oil (Allergopharma-Bracco); DPT and DF whole bodies in petrolatum and petrolatum oil (Lofarma). We found 39% positive reactions among AD subjects and 13% in HV The presence of serum-specific IgE did not influence the patch test results. with of AD patch-lest-positive patients and 5 of 13 HV respectively, showed a positive prick less and or RAST lo Dermatophagoides. Similar sensitization rates were observed with the allergenic material from Bayropharm (54% positivities) and Allergopharma-Bracco (51% positivities), whereas the preparations from Lofarma gave a 20% response rate.     

Active participation of eosinophils in patch test reactions to inhalant allergens in patients with atopic dermatitis

Intracutaneous testing and patch tests with house dust mite and grass pollen allergens were performed in patients with atopic dermatitis. Only patients with an immediate type skin reaction to house dust mite or grass pollen allergens showed a positive patch test reaction to these allergens 24-48 h after testing. Occasionally positive patch test reactions at 20 min, 2 h and 6 h were also observed. Patch test reactions were not found in normal controls or atopic patients without atopic dermatitis. Analysis of the cellular infiltrate demonstrated an influx of eosinophils into the dermis, starting from 2-6 h after patch testing. Immunostaining with antibodies against granular constituents of the eosinophils revealed that the infiltrating eosinophils were in an activated state and had lost part of their granular contents. At 24 h eosinophils also appeared in the epidermis. Electron microscopy showed that in the epidermis, some eosinophils were in close contact with Langerhans cells, suggesting a cell-cell interaction. Taken together, these results strongly suggest an active role for eosinophils in patch test reactions to inhalant allergens in atopic dermatitis patients.     

Swimming pool contact dermatitis caused by 1-bromo-3-chloro-5,5-dimethyl hydantoin

Background. Bromo‐3‐chloro‐5,5‐dimethylhydantoin (BCDMH) is a chemical used as a disinfectant for recreational water. BCDMH was described as being responsible for an epidemic of irritant contact dermatitis in the UK (1983), and its sensitizing capacity was also discussed. Objectives. The aim of this study was to assess whether BCDMH used to disinfect swimming pools and spas can cause allergic contact dermatitis among its users. Methods. Ten patients suffering from dermatitis associated with using swimming pools disinfected with BCDMH and 40 controls were studied. Several dilutions of BCDMH, 10% to 1 ppm, were patch tested. Results. All 10 patients studied showed a positive patch test reaction to BCDMH 1% in petrolatum. At least one case showed occupational relevance, with a positive reaction even at 1 ppm. Conclusion. On the basis of the clinical findings, the positive patch test reactions to BCDMH, and the negative patch test reactions in controls, the suggested diagnosis was allergic contact dermatitis caused by BCDMH used as a disinfectant in the swimming pool water. Contact allergy should be taken into consideration when patients suffer from swimming pool‐associated itchy dermatitis.     

Iodopropynylbutyl carbamate 0.2% is suggested for patch testing of patients with eczema possibly related to preservatives

BACKGROUND: Iodopropynyl butylcarbamate (IPBC) is a new preservative in medical and cosmetic leave-on products. Although cases of allergic contact dermatitis to IPBC have been reported, it is not known whether the usual test concentration of 0.1% is appropriate for screening tests with IPBC. OBJECTIVES: To determine the concentration of IPBC that should be used in screening patch tests. METHODS: An analysis was made of data filed by 26 centres of dermatology on patch tests performed with one or two concentrations of IPBC (0.1%, 0.2%, 0.3% or 0.5%) in 8106 unselected patients. Criteria used to determine the best test concentration of IPBC were the reaction index, the positivity ratio, the rate of crescendo reactions, and the relations between IPBC reactions and the MOAHLFA index irritant reactions to sodium lauryl sulphate (SLS), and allergic reactions to other contact allergens including preservatives. RESULTS: IPBC 0.1%, 0.2%, 0.3% and 0.5% yielded 0.5%, 0.8%, 1.3% and 1.7% positive reactions, but this increase was accompanied by an even greater increase in doubtful and irritant reactions. These figures and the other criteria examined suggested the range of suitable test concentrations of IPBC to lie between 0.2% and 0.3%. A detailed analysis of MOAHLFA indices and of associations between reactions to IPBC and reactions to other allergens and to SLS showed that most of the positive reactions to IPBC 0.2% can be assumed to be allergic ones and that with IPBC 0.2% fewer false-positive reactions can be expected than with IPBC 0.3%. CONCLUSIONS: Patch testing with IPBC 0.2% is suggested for patients with eczema possibly related to preservatives.     

An open study of a lotion formulation to improve tolerance of tacrolimus in facial atopic dermatitis

BACKGROUND: We identified 19 patients with facial atopic eczema who failed to respond to tacrolimus (FK506) ointment, although tacrolimus ointment has shown excellent benefit for the treatment of recalcitrant facial erythema in most patients with atopic dermatitis. OBJECTIVES: We attempted to determine the efficacy of an original lotion formulation of tacrolimus for facial atopic dermatitis resistant to tacrolimus ointment. PATIENTS/METHODS: Recalcitrant facial erythema of these 19 patients was treated with an original tacrolimus lotion preparation for 6 months. Patch testing with white petrolatum was performed in both the 19 patients and in 30 other atopic dermatitis patients who had experienced excellent results with tacrolimus ointment. RESULTS: Of the 19 resistant patients, those whose symptoms were greatly or moderately improved by the lotion were 95%, 89% and 89% after 2 weeks, 3 months and 6 months of treatment, respectively. Further, patch testing to petrolatum showed positive reactions in several (six of 19) patients, compared with none of 30 controls with atopic eczema that had responded to topical tacrolimus ointment. CONCLUSIONS: The tacrolimus lotion had a significant effect on the recalcitrant facial erythema in adult patients with atopic dermatitis who were resistant to tacrolimus ointment. We suggest that one reason for the unresponsiveness to tacrolimus ointment may be because of contact sensitivity to white petrolatum.     

Nickel sensitivity in atopics, psoriatics and healthy subjects

A prospective study of 552 persons was performed lo study nickel allergy in atopics, with and without dermatitis, psoriatics and healthy adults. We found no statistically-significant difference in the frequency of nickel allergy between persons with atopic dermatitis, atopics without dermatitis and healthy controls. More females than men gave a history of metal intolerance and gave allergic patch test reactions. A poor correlation between history and patch lest reaction was not specific for atopics. Psoriatics had a significantly lower frequency of allergic patch test reactions lo nickel than healthy controls or atopics with and without dermatitis. Psoriatics should not be used as controls for atopics in studies of contact dermatitis.     

Pustular patch test reactions in atopic dermatitis.

Pustular patch test reactions to 5% nickel sulfate were regularly produced in patients with atopic dermatitis when patches were placed over areas of skin with (a) follicular papules, (b) erythema, (c) lichenification, and (d) minimal trauma. The pustular patch test reactions seldom occurred in the normal-appearing skin of these patients. However, if the skin was traumatized prior to the patch test, the reaction was produced in the normal-appearing skin of atopic as well as control individuals. No pustular reactions occurred in the follicular lesions of keratosis pilaris, supporting the view that follicular lesions of atopic dermatitis differ from keratosis pilaris. It is suggested that pustular patch test reactions are caused by primary irritation.     

Allergic paraben and benzyl alcohol hypersensitivity relationship of the "delayed" and "immediate" varieties

From a review of the literature, and the results of scratch, intracutaneous and subcutaneous injections of patients with parbens and benzyl alcohol sensitivity of the delayed type characterized by allergic contact dermatitis and strongly positive patch patch tests, it would appear that such sensitivity is not usually accompanied by the immediate urticarial type of allergic sensitivity. This communication concerns itself with results of testing patients with clinical sensitivity and positive patch test reactions to the parabens or benzyl alcohol with scratch, intracutaneous and subcutaneous injections of these preservatives in order to determine the relationship of the "delayed" type of allergic hypersensitivity to the parabens and benzyl alcohol with the "immediate" variety of hypersensitivity. The parabens and benzyl alcohol are widely employed as preservatives for many allergenic extracts used in scratch and intracutaneous testing. In addition, these preservatives are used in injectable corticosteroid medicaments and in local anesthetic solutions. In order to determine whether the presence of these preservatives in allergenic extracts would produce false positive scratch or intracutaneous tests or might produce an immediate, urticarial or anaphylactic reaction in patients with allergic contact dermatitis and positive patch test reactions to these preservatives, two patients with positive patch test reactions and allergic contact dermatitis to the parabens and two with similar benzyl alcohol sensitivity were tested in the manner detailed in the following case reports.     

FS04.5Iodopropynylbutyl carbamate (IPBC) 0.2% is suggested for patch testing of patients with eczema possibly related to preservatives

Iodopropynylbutyl carbamate (IPBC)is a preservative that has been increasingly used for skin care products and cosmetics within the last years and the first cases of contact sensitization have meanwhile been reported. Therefore, a surveillance for IPBC contact allergy is now necessary. Our study was aimed to find out a suitable test concentration of IPBC for this purpose. The data 8106 patients tested by 23 centres of the German Contact Dermatitis Research Group (DKG) and the Information Network of Departments of Dermatology (IVDK)in the time from May 2001 to July 2003 with IPBC in concentrations of 0.1%, 0.2%, 0.3%, and 0.5% were retrospectively evaluated. Criteria considered to determine the optimal test concentration of IPBC were the reaction index, the positivity ratio, the rate of crescendo reactions, and the relation of IPBC‐reactions with MOAHLFA‐indices, with irritant reactions to sodium lauryl sulfate, and with positive reactions to the most common standard contact allergens and 4 other preservatives. For statistical evaluations the exact McNemar test was applied and odds ratios were calculated according to the profile likelihood method, as derived from logistic regression analyses. The rate of positive reactions to IPBC increased from 0.5% with IPBC 0.1% to 1.7% with IPBC 0.5%, but there was a problem with sensitivity or specificity with both of these 2 concentrations. Therefore, we focused on IPBC 0.2%(0.8% positive reactions) and IPBC 0.3%(1.3% positive reactions) for further detailed analyses. An evaluation of the related parameters revealed that with IPBC 0.2% as compared to IPBC 0.3% a higher percentage of crescendo reactions, a higher reaction index, a lower number of doubtful reactions, a plausible association of positive reactions with reactions to other preservatives, nd no association with a pronounced skin irritability was found. In conclusion, we recommend to start with IPBC 0.2% for patch testing of all persons with contact dermatitis that may be related to preservatives.     

Japanese cedar pollen as an exacerbation factor in atopic dermatitis: results of atopy patch testing and histological examination

Atopy patch testing with Japanese cedar pollen extract has been used to investigate patients with atopic dermatitis whose condition is exacerbated by contact with Japanese cedar pollen. Comparative atopy patch testing, scratch tests, and assays for total IgE and specific IgE were performed in 74 patients with atopic dermatitis, 5 patients with Japanese cedar pollinosis and 15 control subjects. A skin biopsy was performed on any sites that were positive to Japanese cedar pollen patch test. The results after 48 h of atopy patch testing were compared with the patient's history, skin scratch test and specific IgE. Twenty-two of the 74 patients (30%) had a history of exacerbation every spring after contact with Japanese cedar. Of these patients 68% showed a positive reaction to Japanese cedar pollen extract, as did 21% of patients with atopic dermatitis without a history of exacerbation by Japanese cedar pollen, 20% of patients with Japanese cedar pollinosis without eruption and 7% of control subjects. A histological examination revealed eczematous changes and infiltration of lymphocytes and eosinophils in atopy patch testing positive sites. In conclusion, atopy patch testing with Japanese cedar pollen extract is a useful method for investigating trigger factors for eczematous skin lesions in a subgroup of patients with atopic dermatitis.     

Allergic contact dermatitis to topical preparations of bufexamac

In Australia bufexamac is mainly used for pharmacist-initiated local treatment of various dermatoses. The European Medicines Agency's Committee for Medicinal Products for Human Use recently recommended that marketing authorisation for bufexamac-containing preparations be revoked throughout the European Union because of the risk of severe allergic contact dermatitis. We retrospectively reviewed the patch test database at the Skin and Cancer Foundation Inc. and identified 19 cases of positive reactions to bufexamac (5% petrolatum) from 451 people patch tested. The bufexamac reaction was deemed relevant to the presenting dermatitis in 13 of 19 (68%) patients. Bufexamac allergic contact dermatitis is under-reported in the English literature. We wish to emphasise the severity and the unusually polymorphic eruptions observed in some of the cases. Clinicians should consider the possibility of allergic contact dermatitis to bufexamac-containing preparations in all patients where there is a history of exposure, even if used for only a short time.     

Atopic background in patients with occupational hand eczema

Of 368 patients with hand eczema examined during the years 1978-79, at a Department of Occupational Dermatology, 39% had a history of atopic disease (dermatitis, asthma, or rhinitis). 28% of the patients had or had had atopic dermatitis. The % of atopics in the patient material was highest in the age range 20-24 years, in which 57% of the patients had a history of atopic dermatitis, compared with only 11% in the age range above 35 years. Of all patients with a history of atopy, 22% had developed allergic contact dermatitis, while the corresponding figure for non-atopics was 45% (p less than = 0.001). Positive patch test reactions occurred in a significantly smaller number of individuals with past or present atopic disease than in non-atopics. Atopics had not changed jobs because of hand eczema to a greater extent, but had healed to a lesser extent after change of occupation than non-atopics (p less than 0.01).     

Lyral is an important sensitizer in patients sensitive to fragrances

Contact allergy to fragrances is a common problem world-wide. The currently used fragrance mix (FM) for patch testing has only eight constituents and does not identify all fragrance-allergic patients. As perfumes may contain 100 or more substances, the search for markers for allergy continues. The synthetic fragrance 4-(4-hydroxy-4-methylpentyl)-3-cyclohexene carboxaldehyde (Lyral) was tested together with the FM and 11 other fragrance substances on consecutive patients in six European departments of dermatology. All patients were carefully questioned regarding a history of reactions to scented products in the past and were grouped into four categories: 'certain', 'probable', 'questionable' and 'none'. Lyral (5% in petrolatum) gave a positive reaction in 2.7% of 1855 patients (range 1.2-17%) and ranked next to 11.3% with FM allergy. Twenty-four patients reacted to both Lyral and FM, but 21 (1.1%) reacted positively only to Lyral. Of 124 patients with a 'certain' history, 53.2% reacted to the FM and a further 7.2% to Lyral only. If any kind of history of fragrance intolerance was given, 80% (40 of 50) of Lyral positive patients had a 'positive' history while only 58.6% (123 of 210) of FM positive patients had such a history; this difference was significant at P < 0.01. Lyral was identified by gas chromatography-mass spectrometry in some products which had caused an allergic contact dermatitis in four typical patients who showed a patch test positive to Lyral and negative or doubtful to FM. In conclusion, we recommend the testing of 5% Lyral (in petrolatum) in patients suspected of contact dermatitis.     

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.