Search PubMed⌕ Search

Biomedical subjects

M Bruze

Publications and source records attributed to M Bruze.

At least 37 records · Page 2Linked to original sources
PubMed2003

The fragrance hand immersion study - an experimental model simulating real-life exposure for allergic contact dermatitis on the hands.

Recently, we showed that 10 x 2% of consecutively patch-tested hand eczema patients had a positive patch test to a selection of fragrances containing fragrances relevant to hand exposure. In this study, we used repeated skin exposure to a patch test-positive fragrance allergen in patients previously diagnosed with hand eczema to explore whether immersion of fingers in a solution with or without the patch-test-positive fragrance allergen would cause or exacerbate hand eczema on the exposed finger. The study was double blinded and randomized. All participants had a positive patch test to either hydroxycitronellal or Lyral (hydroxyisohexyl 3-cyclohexene carboxaldehyde). Each participant immersed a finger from each hand, once a day, in a solution containing the fragrance allergen or placebo. During the first 2 weeks, the concentration of fragrance allergen in the solution was low (approximately 10 p.p.m.), whilst during the following 2 weeks, the concentration was relatively high (approximately 250 p.p.m.), imitating real-life exposure to a household product like dishwashing liquid diluted in water and the undiluted product, respectively. Evaluation was made using a clinical scale and laser Doppler flow meter. 3 of 15 hand eczema patients developed eczema on the finger immersed in the fragrance-containing solution, 3 of 15 on the placebo finger and 3 of 15 on both fingers. Using this experimental exposure model simulating real-life exposure, we found no association between immersion of a finger in a solution containing fragrance and development of clinically visible eczema on the finger in 15 participants previously diagnosed with hand eczema and with a positive patch test to the fragrance in question.

Adult↗
PubMed2003

Contact dermatitis from electrocardiograph-monitoring electrodes: role of p-tert-butylphenol-formaldehyde resin.

Three cases of allergic contact dermatitis localized to the sites of electrocardiograph-monitoring electrodes are reported. All patients had positive patch tests to both the gel and the adhesive part of the Red Dot 2239 3M monitoring electrode used and to the p-tert-butylphenol-formaldehyde resin (PTBP-F-R) of the standard series. Two patients had a history of possible exposition to the resin previously but there was no explanation for the third. No information about the presence of PTBP-F-R in the electrodes could be obtained from the manufacturers. Chemical analysis of samples of the electrode, using a gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography (HPLC) analytical system, demonstrated the presence of several PTBP-F-R derivatives in both the gel and the adhesive part.

Adhesives↗
PubMed2003

Citral a fragrance allergen and irritant.

Citral is a well known contact allergen and a contact irritant. Routine patch testing in the past may have been restricted because of possible irritant (IR) patch test responses. 586 consecutive patients, with hand eczema, were patch tested with a selection of fragrances including citral 2% petrolatum and the European standard series. 28 of the patients showed a positive patch test reaction (+ to +++) to citral and 82 at least 1 IR patch test reaction and no positive patch test reaction to citral. A statistically significant association between a positive patch test reaction to citral and positive patch test reactions to other fragrances compared with IR reactions (n = 82) was established. The difference regarding fragrance history found between those with IR and positive reactions to citral was not significant. Citral could be an allergen and/or irritant, worthy of further more extensive studies.

Acyclic Monoterpenes↗
PubMed2003

Methylisothiazolinones elicit increased production of both T helper (Th)1- and Th2-like cytokines by peripheral blood mononuclear cells from contact allergic individuals.

BACKGROUND: Delayed-type hypersensitivity reactions to nickel (Ni2+) in humans are associated with increased production of both T helper (Th) 1- and Th2-like cytokines. Cytokine responses to the major group of contact allergens, i.e. organic compounds, have been less extensively studied. We have investigated here the cytokine production induced by a mixture of methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI), the active ingredients in common preservatives that are capable of eliciting allergic contact dermatitis. OBJECTIVE: To characterize the immune response induced by MCI/MI in terms of the production of Th1- and Th2-like cytokines in peripheral blood mononuclear cells (PBMC) from allergic and non-allergic subjects. METHODS: Ten subjects with a history of contact allergy to MCI/MI and nine age-matched non-allergic volunteers participated. Their actual status was confirmed by patch testing. PBMC were cultured in the presence or absence of MCI/MI; cell proliferation was measured employing [3H]thymidine incorporation; and the number of cytokine-producing cells was determined using the enzyme-linked immunospot (ELISpot) assay and the levels of soluble cytokines in culture media by the enzyme-linked immunosorbent assay (ELISA). RESULTS: The proliferative response of PBMC to MCI/MI was significantly greater in the case of the allergic group than for the non-allergic group, as was the production of interleukin (IL)-2 and IL-13 (as determined by ELISpot and/or ELISA). PBMC from three of the allergic individuals with increased production of IL-2 and IL-13 responded to MCI/MI with elevated numbers of cells producing IL-4 and IL-5. The increases in the production of IL-2, IL-4, IL-5 and IL-13 were positively correlated. CONCLUSION: MCI/MI elicited concomitant production of both Th1- and Th2-like cytokines by PBMC from subjects with contact allergy to these substances. This finding indicates that the organic compounds MCI/MI elicit a mixed Th1- and Th2-type of response, similar to that elicited by the metal ion Ni2+ in Ni2+-sensitized individuals.

Adult↗
PubMed2002

Monitoring levels of preservative sensitivity in Europe. A 10-year overview (1991-2000).

A 10-year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re-evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave-on products.

Allergens↗
PubMed2002

Further important sensitizers in patients sensitive to fragrances.

In order to find sensitizers additional to the current fragrance mix (FM) a series of fragrance materials (series II) was evaluated in 6 dermatological centres in Europe. 11 of the test materials were essential oils, the remaining 7 being either mixtures of isomers or simple chemicals of frequent usage in the perfume industry. 1606 patients were consecutively tested with series II and 8% FM. Each patient was classified regarding a history of adverse reactions to scented products: certain, probable, questionable, none. Reactions to FM occurred most frequently in 11.4% of the subjects. The 6 materials with the highest reactivity after the FM were ylang-ylang oil (YY) I (2.6%), YY II (2.5%), lemongrass oil (1.6%), narcissus absolute (1.3%), jasmine absolute (1.2%) and sandalwood oil (0.9%). 48 (3.0%) of the patients reacted only to materials of series II and not to FM. 6.0% of 1606 patients gave a history of adverse reactions to fragrances which was classified as certain. This group reacted to FM only in 22.9%, to series II and FM in 15.6% and to series II only in 5.2%. 63.5% of the patients reacting to both FM and 1 of the materials of series II had some type of positive fragrance history, which was higher in comparison to those with isolated reactions to FM (46.2% of 121) or to series II, respectively, (45.8% of 48). However, this difference was not statistically significant. In conclusion, the materials of series II identified a further subset of patients with a fragrance problem, which would have been missed by the current FM as the single screening tool for patch testing.

Dermatitis, Allergic Contact↗
PubMed2002

Sensitizing capacity and cross-reaction pattern of the isomers of diglycidyl ether of bisphenol F in the guinea pig.

In this study, the sensitizing capacities of the 3 main low-molecular-weight isomers of epoxy resins based on diglycidyl ether of biphenol F (DGEBF) were investigated in a guinea pig maximization test (GPMT). The isomers are p,p'-DGEBF, o,p'-DGEBF, and o,o'-DGEBF. The sensitization capacities were compared to diglycidyl ether of bisphenol A (DGEBA), which is the main constituent in the most common epoxy resin. The cross-reaction pattern between all 4 compounds was also investigated. It was found that all 3 DGEBF isomers were potent sensitizers. It was also found that p,p'-DGEBF, o,p'-DGEBF, and DGEBA cross-reacted with one another, and that animals induced with o,o'-DGEBF reacted significantly only to o,p'-DGEBF, but not to the other 2 DGEBF isomers or DGEBA.

Allergens↗
PubMed2002

Occupational allergic contact dermatitis caused by isocyanates.

Between 1978 and 2001, 22 patients were diagnosed with occupation-related allergic contact dermatitis from isocyanates and/or polyurethanes in our clinic. 13 had a positive reaction to the isocyanates, of whom 10 also reacted to diaminodiphenylmethane (MDA), which is used in the production or processing of isocyanates and polyurethanes; 9 reacted only to MDA. The object of the present study was to identify the trades and industries responsible for the development of contact allergy to these resins. Such patients must be patch tested with the isocyanates contacted at work, and account must be taken of positive reactions to MDA as a marker for isocyanate sensitivity.

Adult↗
PubMed2002

Further important sensitizers in patients sensitive to fragrances.

The aim of this study was to determine the frequency of responses to selected fragrance materials in consecutive patients patch tested in 6 dermatological centres in Europe. 1855 patients were evaluated with the 8% fragrance mix (FM) and 14 other frequently used well-defined fragrance chemicals (series I). Each patient was classified regarding a history of adverse reactions to fragrances: certain, probable, questionable, none. Reactions to FM occurred in 11.3% of the subjects. The 6 substances with the highest reactivity following FM were Lyral (2.7%), citral (1.1%), farnesol P (0.5%), citronellol (0.4%), hexyl cinnamic aldehyde (0.3%), and coumarin (0.3%). 41 (2.2%) of the patients reacted only to materials of series I and not to FM. 6.6% of 1855 patients gave a history of adverse reactions to fragrances which was classified as certain. This group reacted to FM only in 41.1%, to series I and FM in 12.0% and to series I only in 7.2%. 74.3% of the 39 patients reacting to both FM and 1 of the materials of series I had any type of positive fragrance history, which was significantly higher in comparison to those with isolated reactions to series I (53.6% of 41), p = 0.04. The study identified further sensitizers relevant for patch testing of patients with contact dermatitis, of which Lyral is the most important single chemical.

Allergens↗
PubMed2001

The time-dose-response relationship for elicitation of contact dermatitis in isoeugenol allergic individuals.

The elicitation response in allergic contact dermatitis is dose dependent, but the time-concentration relationship for elicitation has not previously been described. In this study 27 isoeugenol-sensitive patients participated in serial dilution patch tests with isoeugenol and a double-blinded Repeated Open Application Test (ROAT) using two concentrations of isoeugenol, 0.2 and 0.05%. Seven controls without isoeugenol allergy were also included. The participants applied 3.72 +/- 1.57 (mean +/- SD) mg/cm(2) of coded isoeugenol solutions twice a day to a 3 x 3 cm(2) area on the volar aspect of the right and left arm, respectively. For each test site the applications continued until a reaction appeared or for a maximum of 28 days. The minimal criteria for a positive reaction regarded as allergic contact dermatitis was persistent erythema at the ROAT test site. All controls were negative and 16/24 (66.7%) of the included isoeugenol-sensitive subjects showed a positive ROAT to the 0.2% solution within the study period (Fisher's test, p = 0.0024). Ten of the positive patients also reacted to the 0.05% solution. The median number of days until a positive reaction to the 0.2% solution was 7 days and was 15 days for the 0.05% solution. There was a highly significant correlation between the patients' patch test threshold and the number of days until a positive ROAT. In conclusion, the time until an isoeugenol allergic individual reacts in a ROAT depends on the individual sensitivity as well as the exposure concentrations; for low concentrations of the allergen or low degree of sensitivity, the allergic contact dermatitis may develop after several weeks of exposure. Therefore, a negative ROAT after 7 days may be a false negative.

Administration, Topical↗
PubMed2001

Mechanism of the antigen formation of carvone and related alpha, beta-unsaturated ketones.

In the present study, the mechanism for the antigen formation of alpha, beta-unsaturated ketones was investigated. A series of analogues of carvone ((5R)-5-isopropenyl-2-methyl-2-cyclohexenone) with altered chemical reactivity and with retained overall structure or with retained reactivity and altered three-dimensional structure were synthesized. These analogues were tested for cross-reactivity in carvone-sensitized animals. Cross-reactivity was observed for analogue 3 ((5R)-5-isopropyl-2-methyl-2-cyclohexen-1-one). No cross-reactions were observed for analogues 1 ((2R,5R)-5-isopropenyl-2-methyl cyclohexanone) and 4 ((5R)-2,3-dimethyl-5-isopropenyl-2-cyclohexene-1-one). Both those compounds also failed to induce sensitization. These findings demonstrate that alpha, beta-unsaturated ketones form antigens after a nucleophilic attack at the beta-carbon with soft nucleophiles such as thiol in cysteine and not with the formation of a Schiff's base after a nucleophilic attack at the carbonyl carbon with nitrogen nucleophiles. Furthermore, no cross-reactivity was observed between R- and S-carvone indicating the importance of the 3-dimensional structure of haptens (and antigens) in T-cell recognition. The analogues were also tested for cross-reactivity on patients allergic to carvone. The results from the animal study were confirmed.

Allergens↗
PubMed2001

Standardization of the TRUE Test imidazolidinyl urea and diazolidinyl urea patches.

The preservatives imidazolidinyl urea (IMID, Germall 115) and diazolidinyl urea (DU, Germall II) are commonly used in cosmetic products and are well-known sensitizers. The aim of the present study was to establish the optimal patch test concentration in hydrophilic dried-in vehicle (TRUE Test) for IMID and DU. 181 patients were included in the study. Of these, 150 were patients referred for patch testing, 12 were patients with known allergy to IMID and 19 were patients with known allergy to DU. 76 consecutive patients and the 12 IMID-allergic patients were patch tested with a dilution series IMID (0 to 600 microg/cm(2)), formaldehyde (180 microg/cm(2)) and DU (200 microg/cm(2)). 74 consecutive patients and the 19 DU-allergic patients were patch tested with a dilution series of DU (0 to 600 microg/cm(2)), formaldehyde (180 microg/cm) and IMID (200 microg/cm(2)). A positive dose-response relationship was found. The number of doubtful reactions decreased with increasing test concentrations. No late reactions were observed. A patch test concentration in hydrophilic dried-in vehicle (TRUE Test) of 600 microg/cm(2) was found to be adequate and safe for both IMID and DU.

Allergens↗
PubMed2001

Degradation of triglycidyl isocyanurate as a cause of false-negative patch test reaction.

Triglycidyl isocyanurate (TGIC) is mainly used in polyester-based powder paints, but also in laminates, insulating varnishes, coatings and adhesives. Several cases of contact allergy to TGIC have been reported during the last 10 years. Contact allergy to TGIC has developed in a factory producing the chemical, in a factory producing powder paints containing TGIC, and in industries using powder coating. In this paper, we report a man who developed a work-related dermatitis when working on the painting of metal frames. He was exposed to polyester powder pigments containing TGIC. When patch tested, he was negative to TGIC (prepared in 1988) 3x and positive to polyester powder pigment. Only when a new test preparation of fresh TGIC powder was tested, was a positive reaction obtained. Chemical analyses showed that there was no TGIC in the test preparation from 1988, and that in the TGIC powder from 1988, there was only 30% of the expected amount of TGIC. The investigations, clinical and chemical, strongly indicate degradation of TGIC in the test preparation and powder. Both substances and the test preparations made from them may change over time. Therefore, if a false-negative reaction due to a test preparation is strongly suspected, we recommend a re-test of the patient with a new test preparation of fresh material. As a general rule, patch testing should be performed with fresh substances and test preparations made from them, unless their stability and durability are known.

Adult↗
PubMed2001

Repetitive usage testing with budesonide in experimental nickel--allergic contact dermatitis in individuals hypersensitive to budesonide.

BACKGROUND: Contact allergy to topical corticosteroids on patch testing is well recognized, but the clinical significance is uncertain. OBJECTIVES: To determine the clinical relevance of contact allergy to topical corticosteroids. METHODS: Seven patients hypersensitive to both budesonide and nickel repeatedly applied budesonide, betamethasone valerate or the common base for both corticosteroids to areas of experimentally induced nickel dermatitis. Nineteen controls allergic to nickel, but not budesonide went through the same procedure. RESULTS: Seventy-one per cent of the budesonide-allergic individuals experienced distant ipsilateral flares of toxicoderma-like eruptions, in addition to a severe deterioration of the experimental dermatitis treated with budesonide, i.e. increased erythema, and abundant papules and vesicles. The areas of dermatitis in all of the 19 controls healed uneventfully. CONCLUSIONS: The clinical relevance of a contact allergy to budesonide was thus substantiated.

Administration, Topical↗
PubMed2001

Flare-up reactions after oral challenge with nickel in relation to challenge dose and intensity and time of previous patch test reactions.

BACKGROUND: In this study we have taken an interest in systemic exposure to nickel in patients with delayed hypersensitivity to nickel. OBJECTIVE: The aim of the study was to more closely investigate the importance of factors such as ingested nickel dose, time interval between nickel patch testing and oral nickel challenge as well as degree of nickel hypersensitivity in relation to flare-up reactions. METHODS: Thirty nickel-sensitive female subjects were patch tested with a serial dilution of nickel sulfate in water on 4 different test occasions during a period of 7 months. One month after the last patch test the patients were randomly divided into 3 different groups. The patients in the groups were challenged orally with a placebo capsule, 1.0 mg nickel, or 3.0 mg nickel. RESULTS: None of the patients challenged with placebo had flare-up reactions of earlier patch test sites, but 2 of the patients challenged with 1.0 mg nickel and all of the patients challenged with 3.0 mg nickel had flare-up reactions. There were significantly more flare-up reactions of the most recent patch test sites (1 month) compared with the most distant (8 months) test sites. There was also a statistically significant positive correlation between the intensity of previous positive patch tests and the flare-up reactions. CONCLUSION: In the assessment of the possibility of systemic allergic contact dermatitis from nickel, the dose as well as the intensity and time since previous nickel eczema have to be considered.

Administration, Oral↗