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Stability of thiuram disulfides in patch test preparations and formation of asymmetric disulfides.

The thiuram mix used in patch testing originally contains 4 compounds. However, chemical analysis of the test preparation revealed that several new compounds are spontaneously formed during storage. The structures of these compounds have been determined and the rate of their formation has been studied in buffer solution at pH 7.4. After a few hours, a large amount of mixed disulfides are formed in solutions originally containing only symmetric disulfides. The impact on the test result of the formation of asymmetric disulfides has been investigated by testing on thiuram-sensitive volunteers with different preparations of mixed thiuram disulfides. In our study, the formation of new asymmetric thiuram disulfides from the original symmetric thiuram disulfides in the test preparation had no influence on the result of the patch testing. However, as the chemical analysis showed that the mix composition changes during the period when the preparations are used, and differs between suppliers, the question is raised as to whether it is acceptable to use test preparations with a composition that is different from that labelled on the protocol.

Allergens↗

Sympathomimetic drug allergy: cross-reactivity study by patch test.

INTRODUCTION: Sympathomimetic (alpha-adrenergic) drugs are mainly used because of their vasoconstrictor properties, for nasal congestion, or as mydriatics. Although sympathomimetic drugs are used often, allergic reactions are rare, especially when the drugs are administered systemically. Cross-reactivity may exist among catecholamine derivatives, although reported data on this are contradictory. In this study, we investigate if there is cross-reactivity in patch tests among these drugs. MATERIAL AND METHODS: Patch tests with 10% phenylephrine and 10% pseudoephedrine in petrolatum, and 10% and 20% ephedrine, 10% phenylpropanolamine, 5% fepradinol, 1% methoxamine, and 10% oxymetazoline, all administered in dimethyl sulfoxide (DMSO), were carried out in 14 patients with a history of allergy to any of these drugs. DMSO was used as the negative control. RESULTS: All patients except one (patient number five) showed positive patch-test reactions to at least two different drugs. Nine patients (64.3%) were cross-sensitized to three or more different drugs, and 57.1% of patients were sensitized to four or more sympathomimetic drugs. Patients who experienced generalized rashes caused by orally administered pseudoephedrine had a stronger response and more cross-reactivity with other sympathomimetic drugs in patch tests than those who experienced local contact dermatitis. CONCLUSIONS: We conclude that there is cross-reactivity among the different sympathomimetic drugs tested, especially if the drug is administered systemically.

Adult↗

Day 4 is better than day 3 for a single patch test reading.

Readings were performed on day (D) 2, D3 and D4 after application of patch tests in 88 patients. 90 patch test reactions in 49 patients were interpreted as allergic and of past or present relevance. A single D2 reading detected 58 of the allergic reactions with 32 false-negatives and 23 false-positives. A single D3 reading detected 77 allergic reactions, with 13 false-negatives and 17 false-positives. A single D4 reading detected 85 allergic reactions, with 5 false-negatives and 9 false-positives. Therefore, if only a single reading is feasible, it is better performed on D4 than on D3.

Allergens↗

Type IV hypersensitivity reactions to upper lid gold weight implants-is patch testing necessary?

AIMS: To report two cases of allergic reaction to upper lid gold weight implants in patients with facial nerve palsy and to identify the use of pre-implantation patch testing in predicting gold hypersensitivity. METHODS: One patient who had a positive family history of gold allergy and had undergone previous gold dental restoration underwent patch testing with gold sodium thiosulphate. The gold weight from the same patient was analysed using scanning electron microscopy and energy dispersive X-ray analysis, which can detect surface impurities. Tissue obtained during surgery to remove the gold weight from the second patient was examined histologically. RESULTS: Patch testing in the first patient gave a positive result. Analysis of the gold weight removed from the same patient confirmed 99.99% purity, and hence sensitivity to the gold itself was considered to be the cause of the inflammatory reaction. Histology of tissue taken from the eyelid of the second patient was consistent with type IV hypersensitivity. CONCLUSION: A personal and family history of gold allergy should be looked for before upper eyelid gold weight implantation. Patch testing should be performed for patients where there is doubt about whether gold has been the specific cause of previous allergic reactions, for patients who have undergone previous dental restoration involving gold, or if there is a positive family history of gold allergy.

Aged↗

Value of epicutaneous patch testing in patients with oral, mucosal lesions of lichenoid character.

The purpose of the present investigation was to determine, in patients with oral mucosal lesions of lichenoid character, whether it is possible with epicutaneous patch tests, to detect those who will react favorably to removal of amalgam. Of 48 patients, 19 (39.6%) showed positive patch test reactions to 1% mercury ammonium chloride, and 29 (60.4%) showed negative test results. The observation period varied from 3 months to 3 yr (mean value 1.5 yr). After treatment, 94.7% of the positive group and 86.2% of the negative group showed regression of lesions. Reactions exceeding the contact zone between amalgam restorations and lesions showed positive patch test results in 21% of the cases, as compared with 47% among those with lesions restricted to the contact areas; 85.7 and 93.9%, respectively, showed regression after removal of amalgam restorations. The results of the present study indicate that removal of amalgam usually affects the lesions favorably and that epicutaneous patch tests are of little prognostic value in patients with oral mucosal lesions of lichenoid character.

Adult↗

The spectrum of cutaneous patch-test reactions in patients with atopic dermatitis.

We have outlined rationale and problems associated with three types of patch tests that may provide diagnostic help in patients with difficult-to-manage AD. Each of these methods is imperfect and in need of greater study using a critical approach, better techniques, more attention to irritant controls, and better definition of atopic populations. Proof of validity for aeroallergen patch testing will necessarily require large quantities of purified antigens. In spite of all these problems, patch testing can be useful and sometimes essential for the diagnosis and management of difficult AD.

Adult↗

Patch test reactions to cosmetic allergens in 1995-1997 and 2000-2002 in Finland--a multicentre study.

Contact sensitivity to cosmetics is common, but the sensitizing chemicals vary between countries and study periods. The present survey aimed at revealing the recent trends in patch test sensitivity with cosmetic chemicals in Finland. We report a retrospective multicentre survey of patch test reactions focusing on cosmetic-related substances and comparing the test results in 1995-97 with those in 2000-02. The most striking increases in the frequency of the patch test sensitivity were found with balsam of Peru and propolis from 4.0% to 6.2% (P < 0.001) and from 0.5% to 1.4% (P < 0.001), respectively, whereas the most prominent decreases were found with methylchloro/methylisothiazolinone and chlorhexidine diglugonate from 2.4% to 1.3% (P < 0.001) and from 1.2% to 0.5% (P < 0.001), respectively. The level of patch test sensitivity to methyldibromo glutaronitrile increased, although not significantly, from 1.0% to 1.5%. An increasing tendency was also found with hair dye chemicals 4-aminophenol and toluene-2,5-diamine or toluene-2,5-diamine sulfate from 1.3% to 3.8% and from 1.4% to 5.2%, respectively, while such a tendency was not found among permanent wave chemicals. The sensitivity level of fragrance mix remained the same (6% - 7%). We conclude that surveys revealing the state of sensitivity to cosmetic chemicals should be performed periodically in different countries.

Allergens↗

Toxicodendron antigen patch test. Degrees of inflammation observed after various time intervals.

Allergic contact dermatitis was elicited with Toxicodendron antigen and the patch test site examined at various time intervals up to one week. The degree of inflammation was rather constant during the observation period. The mean erythema score at 168 hours was not significantly different from the score at 24 hours. These data support the use of a delayed (96-hour) patch test reading as a guide to discriminating between allergic and irritant patch test reactions.

Adult↗

Reproducibility of irritant patch test reactions to sodium lauryl sulfate in a double-blind placebo-controlled randomized study using clinical scoring. Results from a study group of the German Contact Dermatitis Research Group (Deutsche Kontaktallergie-Gruppe, DKG).

Reading of doubtful patch test reactions can be improved by comparing them to defined negative, allergic and irritant controls. For the latter, an irritant patch test is needed that gives sufficiently reproducible results. In our double-blind, placebo-controlled, randomized study, we have analysed the synchronous reproducibility of patch tests with 0%, 0.0625%, 0.125%, 0.25%, 0.5% and 1.0% sodium lauryl sulfate (SLS). Tests and readings were done according to ESCD guidelines. 139 patients (75 women, 64 men) 18 to 77 years old were tested. The % of positive patients as well as the % of reproducible positive reactions increased with rising concentrations of SLS to a maximum of approximately 90% and 85%, respectively, with 1% SLS. Time courses of reactions were also related to the concentration of SLS: with 1% SLS, plateau-type time courses were most common (65%), followed by decrescendo- (23%) and crescendo-type reactions (12%). With 1% SLS, very similar mild to moderate reactions were obtained on days 2 and 3. The reaction threshold and reproducibility of tests were not related to age and sex of patients or to their own assessment of skin irritability. We conclude that 1% SLS is appropriate for an irritant patch test that gives sufficiently reproducible results.

Adolescent↗

Etiology of hand dermatitis among patients referred for patch testing.

BACKGROUND: Hand dermatitis affects many people and has numerous causes. Few reports have looked at the etiology of hand dermatitis across broad demographics. OBJECTIVES: The purposes of this investigation were to (1) determine the causes of hand dermatitis in the population patch-tested at a dermatologic referral clinic, (2) report occupations frequently associated with hand dermatitis, and (3) indicate which substances were the more common allergens among individuals evaluated by patch testing for hand dermatitis. METHODS: A retrospective analysis of patch-test data on 1,034 patients who were evaluated during an 8-year period was performed. RESULTS: Hand dermatitis affected 32% of all patients who underwent patch testing. Allergic contact dermatitis was diagnosed most often (54.4%), followed by irritant contact dermatitis (27.4%). Among women, irritant contact dermatitis of the hands peaked in the third decade and then diminished whereas allergic contact dermatitis of the hands remained fairly constant among patients between 21 and 60 years of age. In contrast, irritant contact dermatitis and allergic contact dermatitis in men peaked in the fifth decade of life. In both genders, hand dermatitis was rare among those 20 years of age or younger and among those 61 years of age or older. Fifty-six percent of hand dermatitis was related to occupation. Health care workers were most often affected by occupational hand dermatitis. The most common allergens for both occupational and non-occupational hand dermatitis were quaternium-15, formaldehyde, thiuram mix, and carba mix. CONCLUSIONS: Since more than half of hand dermatitis cases may be related to occupation, a thorough history should be taken by a knowledgeable clinician. Potentially relevant allergens in the workplace must be identified and tested. These allergens may not be contained in standard trays.

Adult↗

Analysis of patients with allergic patch test reactions to a plastics and glues series.

839 patients were patch tested with a series of 31 plastics and glues allergens at a dermatologic clinic over a period of 7 years. 52 (6%) had a positive patch test reaction to 1 or more such allergens. Clinic charts of 47 patients (out of 52) were available for the study. All but 3 patients had dermatitis on their hands: 17 had only hand dermatitis. 25 (53%) patients' test results were of present or past relevance to their skin diseases. 11 patients (68%) with occupational allergic contact dermatitis (ACD) and 14 (45%) with non-occupational dermatitis had relevant reactions. p-tertiary-butylphenol-formaldehyde resin was the most common allergen (9 cases). 7 patients reacted to diaminodiphenylmethane. 5 patients, who had colophony allergy, reacted to abietic acid and 4 to abitol. There was no reaction to 14 test substances. Special series, such as this plastics and glues series, reveal the cause of ACD less frequently than standard series. However, there is no other way to confirm allergy to these usually industrial allergens, which can also sensitize through non-occupational exposure during hobby working or through unpolymerized monomer left in the finished plastic product.

Adhesives↗

Patch test reactions to the acetone-soluble fraction of human dander in atopic dermatitis.

An acetone-soluble fraction of human dander provoked positive patch test reactions in 45 (38%) of 120 patients with atopic dermatitis. The positive patch tests were rare in normal controls and clinical controls. The positive patch test reactions histologically showed spongiosis and mononuclear cell migration in the epidermis, edema and mononuclear cell infiltrate in the upper dermis. Scratch tests with the acetone-soluble human dander fraction were positive in only 2 (2%) of the 120 patients examined. It was suggested that in a considerable number of patients with atopic dermatitis, an acetone-soluble fraction of human dander provokes a delayed-type skin reaction without inducing an immediate-type skin reaction.

Acetone↗

A left versus right side comparative study of Epiquick patch test results in 100 consecutive patients.

4 strips of 5 Epiquick patch tests (19 allergens plus 1 control) were applied symmetrically in duplicate on the left and right sides of the upper back in 100 consecutive patients. 70 positive allergic patch test reactions were recorded on the left side and 67 on the right side. 67 positive reactions were concordant on both sides (64 with the same score of intensity and 3 with a different score). 3 positive reactions (in 2 patients) on the left side were negative on the right side (1 TMTD, 1 cobalt chloride and 1 wool alcohols). At rechallenge 6 weeks later, they were positive. No explanation could be found for negative results at the first challenge on one side and not on the other. The rate of non-reproducible positive results to the overall number of positive reactions was 4.2%. The good reproducibility rate (95.8%) provides useful information for further comparative studies.

Adolescent↗

Skin barrier function and dermal inflammation. An experimental study of transepidermal water loss after dermal tuberculin injection compared with SLS patch testing.

The reaction of the skin water barrier to dermal inflammation was studied in 15 healthy volunteers. Dermal inflammation was induced either by injection of tuberculin (Mantoux test) or by a 24-h sodium lauryl sulphate (SLS) patch test on the volar forearm. Measurement of transepidermal water loss (TEWL) was used for evaluation of the skin barrier function. Inflammation was quantified by assessment of blood flow by laser-Doppler flowmetry. Measurement from uninvolved skin in the test region > 7 cm distant from the test sites served as control. Measurements were performed twice, separated by an interval of 6 days. Throughout the study, TEWL values were higher in the SLS test sites than in the Mantoux reactions, although the blood flow was significantly increased in Mantoux reactions compared with SLS test sites. This indicates that the impaired skin barrier function caused by SLS is due to a direct cytotoxic effect, and cannot be explained by the inflammatory response alone. At control sites, blood flow and TEWL were significantly higher on the arm with the Mantoux test than the arm with the SLS patch test. The significant inflammation caused by the Mantoux reaction may cause functional alterations in the clinically normal skin > 7 cm distant from the test area.

Adult↗

Quality assurance and standardisation of patch tests for contact allergens skin testing.

The misbranding of raw materials used in the manufacturing of patch tests and the counterfeiting of the final product of these test materials have gained increasing importance in the last decade with respect to the production process in the pharmaceutical industry. To guarantee the performance and safety of a semi-solid pharmaceutical testing form, it is important to make oneself acquainted with the different quality standards and official requirements demanded by the national and international regulations. Moreover it will be necessary to get an idea about the major factors which influence the quality of patch tests and therefore finally the quality of the medical allergic diagnosis.

Allergens↗

[Contact eczema and allergens: an analysis of the preliminary results of patch tests in the Dermatology Service of the National Hospital and University Center in Cotonou].

About a preliminary study of patch-test in 39 cases of contact dermatitis with allergens of international Contact Dermatitis Research (ICDRG), the authors noted 27 (69.2%) positive patch-tests. Men are frequently exposed to formaldehyde and dichromate potassium. Women are more exposed to fragrance-mix and formaldehyde. Hand workers have the uppermost percentage of positive patch-test (90.9%). The authors observed also 16 cases of contact polysensitivity for at least two allergens.

Adolescent↗

Good clinical practice in patch testing: readings beyond day 2 are necessary: a confirmatory analysis. Members of the Information Network of Departments of Dermatology.

BACKGROUND: Despite general recommendations, patch test readings are still sometimes terminated at day 2. OBJECTIVE: The consequences of failure to read patch tests after day 2 and the influence of exposure time to the patches is quantified. METHODS: Patch test data from 9,946 patients with at least one positive reaction at day 2 or later and readings at both days 2 and 3 (from 21,062 patients tested between January 1, 1990, and December 31, 1993) collected by the Information Network of Departments of Dermatology in Germany were analyzed. RESULTS: Comparing results at days 2 and 3, 34.5% of all positive reactions appeared at day 3 only, whereas 8.3% initially judged (weakly) positive were not considered allergic at day 3. Some standard allergens showed specific patterns. Additional positive reactions and an increasing percentage of diminishing reactions can be observed at day 4 (compared with day 3). CONCLUSION: The importance of late reading(s) is emphasized by the proportion of potentially false judgments based on readings at day 2 only.

Allergens↗

[Results of patch tests with mite components in atopic dermatitis patients].

House dust mite lipids were investigated in atopic dermatitis (AD) patients. The analysis showed that eicosapentaenoic acid (EPA) was present at 0.88% in total lipid of Dermatophagoides farinae (Df). In the patch tests with crushed 3 live Dfs, the difference of positive rates between AD patients and controls was statistically significant. In the patch test with secretions from opisthonotal glands of mites, 2% citral contained in both D. pteronyssinus (Dp)s and Dfs showed higher rate of positivity with AD patients than controls without statistically significance. In the patch test with the fatty acids of house dust mites, EPA showed higher rate of positivity with AD patients than controls. There was a statistical significance with 100% (as is) EPA. Histopathological findings by hematoxylin and eosin staining with the skin lesions of AD patients and the positive reactions of patch test with crushed 3 live mites and EPA revealed spongiosis in the epidermis and infiltration of mononuclear cells in the upper dermis. The positive subsets of the mononuclear cells were mostly CD4, HLA-DR and ICAM 1, while CD8 positive cells were rare. Based on these findings, not only mite protein but also mite lipids including secretions from mites should be investigated as mite contact allergens in AD.

Animals↗