Positive Test Reactions Research Articles

P59 Patch test results to plant extracts and chemicals

Objective and methods: We review patch test results from two special patch test series for plant allergens, ‘plant extracts’ and ‘allergenic plant chemicals’, provided by Prof. Hausen (Germany) and tested in 1992–2003. The standard series contained Sesquiterpene‐lactone mix (SL mix) since 1993 (3/1998–10/1999 excluded) and Compositae mix since 3/1998. We present the cases where either SL mix or Compositae mix gave an allergic reaction and where, in addition, the series of plant extracts was tested.Results: SL mix and Compositae mix were tested to 900 patients. Among them, plant extracts were tested in 122 and plant chemicals in 104 cases. 30 patients had an allergic reaction to Compositae mix and 17 to SL mix as well. In the plant extract series, there were more than 5 allergic reactions to feverfew(21), true chamomile(21), arnica(18), chrysanthemum(18), laurel bay leaf(13), tansy(12), gaillardia(9), yarrow(8) and pot marigold(7). In the plant chemical series, there were 9 allergic reactions to parthenolide and single reactions to primin, chlorophorin and Mansonone A.Conclusions: Compositae mix gave a positive test reaction always together with SL mix, which gave a positive reaction in only part of these cases. The concentration of Compositae mix was lowered from 6% to 3% in 1/1999 because of cases of active sensitisation. The lower concentration seems to be reliable for detecting allergy, although it still causes active sensitisation.

FC01.1 Occupational contact dermatitis from methylisothiazolinone

Background: The preservative methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) has been used extensively in various products since the 1980s. Recently, a biocide containing only MI and not MCI has been launched on the Swedish market for use in industrial settings, paints and glues.Objectives: To describe sensitization to the unchlorinated isothiazolinone 2‐methyl‐4‐isothiazolin‐3‐one (MI) in 2 workers, a technician after a chemical burn and a painter, both exposed to a preservative containing MI. Methods: Patch testing with serial dilutions of MCI/MI, MCI, MI, 2‐n‐octyl‐4‐isothiazolin‐3‐one (OIT) and a commercial preservative containing MI in the 2 workers.Results: The patients reacted positively to MCI/MI and to the separate active ingredients (MCI, MI). The patch test reactivity to MI was higher than the reactivity to MCI, which is a reversed pattern to what is usually seen in patients sensitized to MCI/MI. Both patients also had positive test reactions to OIT.Conclusion: MI may sensitize on it’s own, and in patients allergic to MI, cross‐reactions are also seen to MCI.

FS11.2 Contact allergy to herbal teas from Asteraceae plants

Objective: A possible contact allergy to herbal teas, in particular those derived from the Asteraceae plant family, was investigated in patients allergic to sesquiterpene lactones (SL).Method: Twenty patients with a contact allergy to SL were recalled and patch‐tested with aqueous, ethanol and acetone extracts of 8 different herbal teas based on Asteraceae plants as well as with parthenolide and other SL.Results: In 18/20 patients with SL allergy there were positive test reactions to the Asteraceae teas, mainly to those based on German chamomile, dandelion and milfoil. Among the SL, parthenolide was the most frequent co‐reactor.Conclusion: Most patients with a contact allergy to SL are allergic to commercial teas derived from the Asteraceae plant family as well.

Frequent occurrence of IgE to seeds of rape, oilseed rape, mustard and soy in children suspected for food allergies

Rationale We have noted strongly positive skin prick test (SPT) reactions to seeds of Brassicaceae family foods, i.e., rape, oilseed rape and mustard in infants and children suspected for food allergies. Sensitization pathways are not known and some the youngest infants had been exclusively on breast-feeding. Methods Extracts were prepared from seeds and used as solid-phase antigens in IgE ELISA and immunoblotting. Sera from 61 children (aged 3 months to 14 years), all with positive SPT to 1-4 of the foodstuffs, were analyzed. Results In ELISA 64% of the children showed clear IgE binding to rape, 61% to oilseed rape, 69% to mustard, and 38% to soy. Parallel IgE binding to rape, oilseed rape and mustard was common and correlated to the intensity of SPT reactions and serum IgE levels. In IgE immunoblotting major reactivity was to a 9-11 kDa protein which was partially purified by reversed-phase-HPLC and shown to bind IgE from the patient sera in ELISA. Conclusions Children reacting to seeds of rape, oilseed rape and mustard in SPT show also frequently IgE antibodies in ELISA. Major IgE binding allergen seems to be a 9-11 kDa protein, but the route of sensitization and its clinical importance remain to be elucidated.

The study of type 1 allergy prevalence among people of South-East of iran by skin prick test using common allergens.

The prevalence of allergic disorders has increased markedly throughout the world over the past three decades. It seems probable that the increased prevalence is real because longitudinal studies have shown a rapid exponential increase in allergic disorders. In order to determine the prevalence of type 1 allergy in patients with allergic disorders in Sistan-Blouchestan province, in the Southeast of Iran, patients referred to Immunology and Allergy Medical Center of Khatam Hospital during a 7-year period were studied. One thousand two hundred and eighty-six patients (554 males and 732 females), aged 2-79 years, had allergic disorders. The most frequent allergic disease was rhinitis, seen in 959 patients ( 74.57%). Also, 939 patients had a history of sinusitis (73.02%). Among the skin prick test(SPT)-positive patients, a positive prick test reaction to the house dust mites (89.74%), feathers (70.29%), and Aspergillus (65.08%) was most common, followed by Alternaria (57.39%), Cladosporium (47.12%), grasses (43.39%), trees (41.29%), Penicillium (39.19%), fruits (38.41%), and weeds (32.50%). Also, 30.33% of the subjects were sensitized to Hen's egg in the prick test, walnut (29.16%), cow's milk (21.46%), beef meat (19.21%), and hazel-nut (15.32%) accounting for other positive reactions. The prevalence of SPT-positive to common allergens is high among Iranian patients with allergic disorders. So, it should be recognized in the diagnosis of allergic diseases as well as in allergen-reduction programs.

Patch testing with components of water-based metalworking fluids.

Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used.

Which factors explain the lower prevalence of atopy amongst farmers' children?

The inverse association between farming and atopy in children has been attributed to microbial exposure, especially through livestock. Very little is known about other potential explanatory factors. To explore potential differences in lifestyle and environmental factors between farmer and non-farmer families, and whether these factors could explain the association between farming and childhood atopy. A cross-sectional study, including 366 farmers' and 344 non-farmers' children in eastern Finland. Information regarding exposure and background characteristics was gathered by a written questionnaire. Atopy was defined as having one or more positive skin prick test reactions (> 3 mm) against the six common aeroallergens. Regardless of the current farming type, atopy was less frequent among the farmers' children than the non-farmers' children (aOR 0.56, 95% CI 0.40-0.78). Remarkable differences were seen in many lifestyle factors (including diet) between the farmer and non-farmer families, but only a few of the explored factors were associated with atopy. The frequency of current livestock contacts seemed to have an inverse, dose-dependent association with atopy (aOR 0.46, 95% CI 0.22-0.97 for daily vs. no contact). Having lived on a dairy farm in infancy (aOR 0.51, 95% CI 0.28-0.93), or having had cats or dogs in infancy (aOR 0.60, 95% CI 0.42-0.85), decreased the risk of atopy at school age. The inverse association between farming and atopy was not explained by the sociodemographic factors, or by differences in conventional risk factors of atopy. Animal contacts explained partially, but not completely, the association. Higher frequency of animal contacts is one factor, but probably not the only one, explaining the inverse association of farming and atopy in children. The importance of early life exposures may have recently been over-emphasized, and current exposures discounted, when studying the risk factors of childhood atopy.

Rapid serological profiling by enzyme-linked immunosorbent assay and its use as an epidemiological indicator of foot-and-mouth disease viral activity.

Frequency distribution of reactivity levels of foot-and-mouth disease infection-specific antibodies in livestock populations was analysed. Specific antibody responses against non-capsid polyprotein 3ABC were assessed through a highly sensitive indirect enzyme-linked immonosorbent assay (I-ELISA 3ABC). A graphic display of data was designed based on three negative and three positive categories to illustrate reactivity patterns. The resulting patterns were correlated to the epidemiological status. On this basis, results of over 100,000 sera derived from cattle populations in regions with various well-documented epidemiological situations were compiled and are exemplified in this paper.Distinct distributions of antibody reactivity patterns reflecting the various epidemiological situations were attained. Whereas non-affected areas presented a rather homogenous negative pattern with very limited test-positive reactions, affected regions revealed quite heterogeneous profiles, including positive and negative categories, with distributions that varied according to the region. The use of graphic prints encompassing I-ELISA 3ABC antibody profile responses constituted an adequate epidemiological indicator of the risk of foot-and-mouth disease viral activity, providing immediate visualization for a rapid inference of the epidemiological situation of a region. Moreover, such profiles allowed for convenient follow-up of infection after a focus as a function of time and geographical spread.

Patch testing in children, adults, and the elderly: influence of age and sex on sensitization patterns.

Patch testing was done on 2776 consecutive patients (76.5% female) with a locally revised standard series of 34 contact allergens and the results analyzed for age- and gender-specific differences. At least one positive epicutaneous test reaction occurred in 48.9% of patients. Nickel (20.9%), ethylmercuric chloride (13.2%), thimerosal (11.8%), fragrance mix (9.3%), metallic mercury (8.9%), palladium (5.8%), balsam of Peru (3.8%), copper (3.7%), cobalt (3.3%), and chromium (2.3%) were the 10 most important sensitizers. The following tested allergens with sensitization rates of more than 1% were not part of the usual standard series: ethylmercuric chloride, metallic mercury, copper, propolis (1.3%), propylene glycol (1.0%). Reactions to nickel, cobalt, and palladium, but not to chromium, were significantly more abundant in females (p < 0.002, chi-squared test). The overall sensitization rate was highest in children less than 10 years old (62%) and decreased steadily, to be lowest among patients more than 70 years old (34.9%). The rate of positive reactions to nickel and thimerosal decreased with age, while fragrance mix and metallic mercury stayed at the same level through all age groups.

Contact sensitization to N‐(cyclohexylthio)phthalimide

Previous reports revealed relative high sensitization rates to the rubber chemical N-(cyclohexylthio)phthalimide (CTP; CAS-No. 17796-82-6), but the relevance of positive reactions remained unknown. It was discussed whether the test concentration of 1% pet. needed to be changed. The German Contact Dermatitis Research Group (DKG) added CTP in 3 concentrations, i.e. 0.25% pet., 0.5% pet, 1% pet., to the rubber series. From June 1999 to December 2000, 1936 patients in 30 departments of dermatology were tested with CTP. Of the 56 patients with a positive test reaction (2.9%), 52 reacted to CTP 1% pet., 21 to CTP 0.5% pet., and 9 to CTP 0.25% pet. The reaction indices were about the same with all concentrations. 34 patients with a positive reaction to CTP 1% pet. did not react to the lower concentrations. The majority of these reactions are probably false-positive. With CTP 0.25% pet., however, the majority of true allergic reactions to CTP were missed. Analysis of population characteristics and concomitant sensitizations to other rubber chemicals led to the conclusion that a positive reaction to CTP 0.5% pet. was a good indicator of contact allergy to CTP. Thus, the DKG decided to continue patch testing with CTP 0.5% pet. in the rubber series. Manufacturers' information about the use of CTP seem to partly contradict the patients' characteristics seen in this study. So the relevance of positive CTP patch test reactions, and the causative exposures in patients with CTP allergy, still remain to be clarified.

The association between delayed type hypersensitivity reaction to Mycobacterium tuberculosis and atopy in asthmatic children

BackgroundIt has been postulated that there is an inverse association between mycobacterium tuberculosis infection and atopy. We aimed to investigate if there is a similar relation in our study group, consisting 252 asthmatic children MethodsIn tuberculin testing indurations greater than or equal to 5 mm were accepted as positive. The most common aeroallergens were used in skin prick testing and reactions 3 mm were accepted as positive ResultsIn 139 patients PPD was negative, where as in 113 patients PPD was positive. Among the PPD (-) patients skin prick test was positive in 64% (n = 89). Among the PPD (+) patients skin prick test was positive in 71 % (n = 80). As the two groups were compared for having positive skin prick test reactions no statistically significant difference was detected between them (p = 0.283) ConclusionsTuberculin reactivity is not inversely associated with atopy in asthmatic children

Skin prick test reactivity to common aeroallergens in asthmatic patients with and without rhinitis.

The aim of this study was to investigate the prevalence of skin prick test (SPT) reactivity to common aeroallergens among Malaysian asthmatic patients with and without rhinitis. An SPT using eight aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat fur, cockroach, Acacia sp., Bermuda grass, Aspergillus fumigatus and Aspergillus niger) was performed on 206 asthmatic patients. One hundred and forty patients (68%) were reactive to at least one of the aeroallergens. Among the SPT-positive patients, a positive prick test reaction to the house dust mites, D. pteronyssinus (93.6%), and D. farinae (81.4%) was most common, followed by cat fur (20.0%), cockroach (7.9%), Bermuda grass (7.9%), Acacia sp. (7.9%), A. fumigatus (0.7%) and A. niger (0.7%). A history of rhinitis was elicited in 111 (53.9%) patients and 95 (85.3%) of these patients were SPT-positive compared with only 45 (47.4%) of 95 patients with asthma symptoms alone (P < 0.001). The presence of rhinitis and a young age of onset of asthma were independent factors for positive SPT reaction to at least one of the aeroallergens. The prevalence of SPT reactivity to common aeroallergens is high among Malaysian asthmatics, particularly in those with an early age of onset and in those with coexisting rhinitis.

Evaluation of the usefulness of sensitization to aeroallergens as a model for canine atopic dermatitis in genetically predisposed Beagles.

To evaluate a model for atopic dermatitis (AD) and to measure the effect of sensitization in Beagles genetically predisposed to produce high serum concentrations of allergen specific IgE. 22 laboratory Beagles. Seventeen dogs were sensitized from birth to 3 allergens (recombinant birch pollen, Dermatophagoides pteronyssinus, and D farinae). Five nonsensitized dogs from the same litters served as controls. Clinical scoring, regular intradermal testing, measurement of serum concentrations of allergen-specific IgE, and collection of biopsy specimens of skin at 23, 32, and 43 weeks of age were performed. Serial tissue sections were stained for identification of IgE+ cells, mast cells and their subtypes, T-cells, Langerhans cells, and major histocompatibility complex class-II+ cells. At the age of 15 months, dogs were continuously exposed to 2 microg of mite allergen/g of dust. Sensitized dogs had positive intradermal test reactions and significantly higher serum concentrations of allergen specific IgE, compared with nonsensitized dogs. In sensitized and nonsensitized dogs, a significantly higher number of mast cells was found at predilection sites, compared with the control biopsy site. The number of mast cells at predilection sites increased with age. Sensitization significantly increased the number of epidermal Langerhans cells by 23 weeks of age. The number of epidermal Langerhans cells significantly increased in nonsensitized dogs by 32 weeks of age. Clinical scoring only revealed mild transient erythema in some dogs. increases in concentrations of serum allergen-specific IgE and exposure to allergens is not sufficient to induce clinical signs of AD in genetically predisposed dogs.

Allergen‐specific immunotherapy in dogs with atopic dermatitis and house dust mite hypersensitivity: use of symptom/medication scores

There is no published literature on the efficacy of allergen‐specific immunotherapy (ASIT) for dogs with atopic dermatitis (AD) and house dust mite (HDM) hypersensitivity. Symptom/medication (SM) scoring is the standard measure of clinical disease during ASIT in humans. The purpose of this study was to determine the response to ASIT in dogs with AD and HDM hypersensitivity using SM scores, and compare results with the owner’s global assessment and the investigator’s clinical evaluation. All dogs had nonseasonal AD, positive intradermal test reactions to HDM, and were treated for 12 months with ASIT that included HDM allergens. Evaluations at 0, 3, 6, 9 and 12 months included: daily owner symptom (pruritus, lesions, coat character) and medication (all anti‐inflammatory medications) scoring for 28 days; owner global assessment; and investigator clinical sign score. Occurrence of skin infections was documented throughout the study. Statistical analysis of SM scores at 0 and 12 months was performed using Student’s t‐test. Nineteen dogs completed the study. Fourteen (74%) dogs showed significant improvement (P &lt; 0.05) in SM score. A 50% improvement in SM score, owners’ global assessment and clinical sign score was seen in 12 (63%), 17 (89%) and 10 (53%) dogs, respectively. In the first 6 months of ASIT, 17 episodes of skin infections (12 dogs) were recorded, and 13 episodes (10 dogs) in the final 6 months. The majority of dogs with AD and HDM hypersensitivity improved with ASIT. SM scores are a useful semiquantitative measure of clinical disease. Many dogs continued to have skin infections. This study was funded by the Ohio Animal Health Foundation.

Serological responses to house dust mite antigens in atopic dogs while receiving allergen‐specific immunotherapy

In human atopic disease a beneficial response to immunotherapy may be associated with humeral changes in serum IgE and subclass IgG. The aim of this study was to investigate the humeral response to allergen‐specific immunotherapy (ASIT) in dogs with atopic dermatitis. Twelve dogs with clinical signs consistent with atopic dermatitis and positive intradermal test reactions to house dust mite antigens (Greer Laboratories, Lenoir NC, USA) were studied. The clinical response to ASIT (Greer) was evaluated when blood samples were collected at 0, 2 and 4 weeks; and at 3, 6 and 12 months after starting ASIT. The ASIT was administered for a minimum of 9 months. The serum concentration of total and subclass IgG antibodies was measured against Dermatophagoides farinae and Dermatophagoides pteronyssinus antigens (Greer) by ELISA using polyclonal and monoclonal antidog IgG reagents, respectively. Serum IgE was measured using a Fc‐epsilon R1 receptor alpha chain‐based ELISA. The data were analysed using a multilevel model in MLwiN software (Institute of Education, University of London, UK). Antibody concentrations of IgE and total IgG increased during the period of administration of ASIT and decreased after ASIT was stopped. There was no obvious pattern in subclass‐IgG concentrations during ASIT. Response to ASIT was excellent (four dogs), equivocal (three dogs) or poor (five dogs). During ASIT a poor or equivocal response was associated with a statistically significant increase in IgE to D. pteronyssinus antigen compared with the excellent responders. This relationship was present to a lesser extent with IgE to D. farinae and total IgG to both antigens. This study was supported, in part, by the RCVS Alison Alston Canine Award and by Heska Corporation.

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.

Quantitation of latex allergens

Minimizing allergen concentration in latex goods to prevent sensitization to natural rubber latex (NRL) and thereby the development of clinical allergy is acknowledged as of mutual interest for rubber manufacturers and regulatory health authorities. However, measuring total protein, the principal currently available method, cannot be deemed a satisfactory regulatory measure to control allergen content. Specific methods based on human IgE-containing reagents, such as radioallergosorbent test (RAST) inhibition, have been available in certain laboratories for demonstrating NRL allergens in rubber products but the methods lack standardization. Currently, one commercial test has become available for measuring individual NRL allergens by capture ELISA-based assays using monoclonal antibodies and purified or recombinant allergens. Such methods are specific, they can be properly standardized, and they are of sufficient sensitivity and reproducibility. Results from medical gloves collected in two national market surveys in Finland in 1995 and 1999, respectively, show that Hev b 6.02 and Hev b 5, the two major allergens for NRL-allergic adults, are the most abundant allergens regularly detectable in high- and moderate-allergen gloves. In addition, Hev b 3 and Hev b 1, the two major allergens for children with spina bifida, are also commonly found. In general, when the sum of the four allergens exceeded 1 μg/g, most NRL-allergic patients showed positive skin prick test reactions against them. Using these new methods assessment of threshold levels that could in due course become guidelines for the rubber industry and regulatory health authorities is becoming possible. Eventually, this progress is expected to lead to a declining incidence of latex allergy.

Lyral has been included in the patch test standard series in Germany.

Lyral 5% pet. was tested in 3245 consecutive patch test patients in 20 departments of dermatology in order (i) to check the diagnostic quality of this patch test preparation, (ii) to examine concomitant reactions to Lyral and fragrance mix (FM), and (iii) to assess the frequency of contact allergy to Lyral in an unselected patch test population of German dermatological clinics. 62 patients reacted to Lyral, i.e. 1.9%. One third of the positive reactions were + + and + + +. The reaction index was 0.27. Thus, the test preparation can be regarded a good diagnostic tool. Lyral and fragrance mix (FM) were tested in parallel in 3185 patients. Of these, 300 (9.4%) reacted to FM, and 59 (1.9%) to Lyral. In 40 patients, positive reactions to both occurred, which is 13.3% of those reacting to FM, and 67.8% of those reacting to Lyral. So the concordance of positive test reactions to Lyral and FM was only slight. Based on these results, the German Contact Dermatitis Research Group (DKG) decided to add Lyral 5% pet. to the standard series.

Triggerung der atopischen Dermatitis durch Sporen des Austernpilzes Pleurotus pulmonarius

- Spores of the basidiomycete Pleurotus pulmonarius a species of the oyster mushrooms are widespread components in the air and established as causes of respiratory allergies. Recent reports indicate that aeroallergens such as mite allergens, pollen or animal dander may play an important role triggering atopic eczema in a subgroup of subjects with atopic dermatitis. The aim of the study was to investigate whether spores of P. pulmonarius may elicit delayed-type skin reactions in atopic subjects particularly in those with an atopic dermatitis. Sixty-five study subjects were categorized prospectively in 4 groups having atopic dermatitis or respiratory allergy with regard to the skin prick test reactivity to P. pulmonarius spore extract. Twenty nonatopic individuals served as control subjects. Atopy patch test performed with P. pulmonarius spore extract at a concentration of 1.35 mg protein per gram of petrolatum were evaluated after 48 and 72 hours. Of the subjects with atopic dermatitis, 12 of 37 (32%) showed a positive atopy patch test reaction with 7/13 (54%) also having a positive skin prick test response to the P. pulmonarius spore extract. In the study group with respiratory allergy and positive skin prick test to the Pleurotus extract 1 subject with a well-known asthma had a positive atopy patch test. No positive test reaction was observed in the nonatopic control subjects or in subjects with respiratory allergy but negative skin prick test responses to the P. pulmonarius spore extract. Our results demonstrate that spores of the oyster mushroom P. pulmonarius can induce delayed-type reactions consistent with an acute eczema in atopic individuals, particularly in those with atopic dermatitis. Furthermore, it could be shown that individuals with an air-exposed pattern of the atopic dermatitis were most reactive to the atopy patch tests with these spore extract.

Epikutantest-Reaktionen auf Paraben-Mixe und ihre Aufschlüsselungen. Studien der Deutschen Kontaktallergie-Gruppe (DKG) und des Informationsverbundes dermatologischer Kliniken (IVDK), 1990 – 2000

Parabens are commonly used preservatives in topical preparations, including cosmetics, in medicines, and in food. They are capable of inducing contact sensitisation, especially in patients with stasis dermatitis. Between 1990 and 1994, a mix containing 5 parabens (benzyl-, butyl-, ethyl-, methyl- and propylparaben, 3% each) was used for diagnostic patch testing. Of 23025 patients tested with this mix, 1.6% had positive test reactions. In break-down testing with single constituents (tested with 3%) mainly benzyl paraben, which was not tested (and not used) due to possible carcinogenic risk any more, and propyl caused positive test reactions (in 10 of 184 and 13 of 616 patients, respectively). The sensitivity of the mix with regard to detecting contact allergy to one (or more) of the constituents was 88% and specifity 96%; however, the positive predictive value (PPV) was only 23%, i.e., about 3/4 false-positive reactions occurred. In a subsequent study of the German Contact Dermatitis Research Group (DKG) 1286 patients were patch tested with the above mentioned mix, which had to be replaced, and 2 mixes (4 x 3% and 4 x 4%) containing the remaining parabens; positive reactions were observed in 2.1%, 1.2% and 1.5%, respectively. The sensitivity of the new mixes was lower (47% and 53%, resp.), however, the PPV (44% and 42%, resp.) was more acceptable. Between 1995 and 2000 altogether 51260 patients were patch tested with the standard series, including the 4 x 4% paraben-mix in the IVDK centres, with 1.5% positive reactions. Break-down testing was performed in 1270 of these. The diagnostic performance of the mix found here (sensitivity: 78%, PPV: 44%) was similar to that in the DKG-study. In conclusion, patch testing with parabens is still difficult, in particular, as several paraben paradoxes hamper the application of a valid gold standard (e.g., a repeated open application test [ROAT] on uninvolved skin) when judging patch test reactions. Despite these limitations in risk assessment, parabens can be regarded as relatively safe, although this benefit is somewhat limited by the necessity to add other - potentially more sensitising - biocides to achieve adequate protection against microbial decay in some products.