Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Patch Tests”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2007

Variation in the amount of petrolatum preparation applied at patch testing.

The elicitation of a positive patch test reaction in a given individual depends upon the dose of the sensitizer applied, the patch test technique and the occlusion time. The dose is determined by the concentration and volume/amount of test preparation applied. If the same amount/volume of a test preparation is applied all the time with the same test technique (same area of skin) and occlusion time, it is appropriate to use concentration as a dose parameter. Most contact sensitizers are incorporated in petrolatum (pet.). With pet. as vehicle, it is impossible to repeatedly apply an exact volume/amount. This study was performed to investigate the inter- and intra-individual variation of pet. preparation applied at patch testing by 3 technicians. Weighing demonstrated that the 3 technicians had about the same precision in their pet. application. The investigation demonstrates that there is both an inter-individual (statistically significant) and intra-individual variation in the amounts of pet. applied at patch testing for the 3 technicians. Presently, there is no recommendation on what amount of pet. preparation to apply, which merits a decision to be taken based on thorough investigations on the appropriate volumes of pet. preparation to be applied in various patch test systems.

Dermatitis, Contact↗
PubMed1981

Patch testing--a recapitulation.

Although patch testing continues to be one of the most useful office tools of the inquiring dermatologist, the procedure is not used as often as patients deserve. This article reviews the use of the patch test and emphasizes its utility in the practice of dermatology. Although simple to perform, the test requires experience and keen objectivity for accurate interpretation. The rewards are great, however, as between 5% and 10% of dermatology practice consists of contact dermatitis. Failure to diagnose this percentage of patients accurately constitutes an important omission on our parts.

Dermatitis, Contact↗
PubMed1976

Results of routine office patch testing.

The results of patch testing over the past 18 months in a general dermatology clinic are presented and compared with the data recently reported by the North American Contact Dermatitis Group. Good correlation exists between the results of the two studies for all the reported allergens except nickel sulfate and potassium dichromate. The increased incidence of sensitivity to these allergens reported in our series probably reflects the tendency for all metal related contact dermatitis to be referred to our clinic, even though recognized as such by the referring physician. The 16.8% reactivity to a dye mix used in our screening kit, and not reported by others, proved most interesting. In the light of continuing reports of dye related allergic contact dermatitis, our experience prompts us to suggest that a dye mix of some sort should be evaluated in future large-scale studies of patch test screening kits.

Allergens↗
PubMed2006

Patch test responses to Malassezia pachydermatis in healthy dogs.

The effects of the patch test application of Malassezia pachydermatis extracts to normal canine skin were evaluated in eight healthy beagle dogs. Antigens (4 and 0.4 mg/ml) and saline controls were applied for 48 h using filter paper discs in Finn chambers. At the first test, two dogs showed patch test reactivity 20 min and 24 h after patch removal. Four out of six dogs that did not react to the first patch test showed reactivity when re-tested on day 8. Two remaining dogs were patch tested for a third time on day 15, after 7 days of cutaneous challenge with suspensions of M. pachydermatis cells, but failed to display reactivity. Positive patch test reactions were characterized histologically by mild epidermal hyperplasia, superficial dermal oedema and mild to moderate perivascular, periadnexal and interstitial infiltrates of neutrophils and CD3+ lymphocytes. Four dogs showed delayed intradermal test reactivity to M. pachydermatis antigens but intradermal and patch test reactivity did not correlate. This study indicates that patch test reactivity to M. pachydermatis antigen occurs in some healthy dogs exposed to the yeast, or may develop after a short period of antigen exposure. Further studies of patch test reactivity are warranted in dogs with disease associated with this cutaneous yeast.

Animals↗
PubMed2000

Skin hyporeactivity in relation to patch testing.

False-negative patch tests are clinically relevant. Skin hyporeactivity has been suggested as one possible cause. Evidence supports that failure to respond to a specific antigen might be due either to a faulty immune response, a defective inflammatory response or both. Thus, skin hyporeactivity may have clinical relevance in routine patch testing. Articles on this topic are infrequent and there is no index keyword for skin hyporeactivity as this phenomenon is poorly defined and investigated. This article summarizes several observations of skin hyporeactivity, reviews theories of possible mechanisms and discusses further consequences.

False Negative Reactions↗
PubMed1991

Ultrasound B scanning with image analysis for assessment of allergic patch test reactions.

Assessment of patch test results has been performed visually and using ultrasound in the B mode. A positive test site has a typical ultrasonographic appearance, presenting a uniform hypoechogenic area in the dermis. In this zone, the mean amplitude of ultrasound reflection peaks decreases, and the extension of this area increases, together with the intensity of the eczematous reaction. A close correlation has been shown between visual scoring, amplitude decrease and surface increase of the hypoechogenic area. This technique seems to provide a reproducible system for the evaluation of patch tests.

Adolescent↗
PubMed1998

Patch testing with nickel sulfate: comparison between 2 nickel sulfate preparations and 2 different test sites on the back.

Among patients routinely undergoing patch testing for suspected allergic contact dermatitis (ACD), nickel is the most frequently sensitizing hapten, with a clear predominance in the female population. However, some patients who report the appearance of dermatitis upon exposure to metal objects show negative patch test results to a nickel sulfate 5% pet. application. In some cases, a positive response to nickel can be observed simply by repeating the patch test. The objective of our study was to assess if, during routine patch testing, positive responses to nickel sulfate are missed owing to contingent problems, referring to application site, patch test execution or variations in skin reactivity. To this end, we applied 2 different patch test materials containing nickel sulfate 5% pet. to 3040 consecutive patients, undergoing patch testing for suspected allergic contact dermatitis, during the same session. The rôle of the test site was also investigated by applying the preparation on 2 different sites of the back in 30 patients. Of the whole, 612 patients (20%) showed positive patch test responses. The 2 nickel materials were almost equivalent: 78% of nickel-sensitive patients had positive reactions to both, whereas 11% showed a positive response to 1 preparation alone. No variations in patch test responses in relation to application site were observed. Our data show that false-negative patch test responses to nickel are frequent. The use of 2 different preparations during the same patch test session increases the response rate by 10%.

Adolescent↗
PubMed2001

Long-term absence of sensitization to mepivacaine as assessed by a diagnostic protocol including patch testing.

BACKGROUND: Prospective assessment of non-reactivity to local anaesthetics is a frequent reason for allergy consultation. OBJECTIVES: To investigate the clinical profiles of subjects referred for allergy evaluation; to prospectively reduce the frequency of evaluation by assessing the persistence, during clinical use, of non-reactivity to contaminant/additive-free mepivacaine; and to determine the usefulness of a diagnostic protocol involving patch testing. METHODS: In a prospective study, 198 consecutive patients underwent collection of clinical data, skin prick tests and patch tests using allergens/antigens relevant for the investigation, and an intradermal/subcutaneous challenge procedure using contaminant/additive-free mepivacaine, as appropriate. Patients were followed up for 3 years for assessment of non-reactivity persistence using the same diagnostic protocol. RESULTS: Only one-third of the patients had a history of previous adverse local anaesthetic reactions. Absence of sensitization to contaminant/additive-free mepivacaine persisted in all subjects completing the follow-up. Controlled challenge with mepivacaine was negative in 196 patients with both negative specific skin prick tests and patch tests but it was eventful in two subjects with positive specific patch tests. A few subjects displayed positive skin prick tests and/or patch tests for latex and/or additives. CONCLUSIONS: A few patients had a relevant history for potential local anaesthetic-induced adverse reactions. Upon assessment of absence of sensitization and reactivity, contaminant/additive-free mepivacaine could safely be given for as long as 3 years. The patch testing was shown to be useful and safe for prediction of challenge outcomes. True allergic reactions to contaminant/additive-free mepivacaine were not observed in our patient series.

Adolescent↗
PubMed2004

Lessons from atopy patch testing in atopic dermatitis.

The exposure of atopic eczema (AE) patients to their relevant protein allergens (eg, from house dust mite, cat dander, grass pollen, or food allergens) can trigger an exacerbation or maintain the disease. Diagnostic procedures are needed to specify allergen avoidance recommendations for the individual patient. Skin prick tests and specific serum IgE tests might be helpful in pointing out potential trigger factors, but relevance needs to be confirmed (eg, with food provocation tests). The atopy patch test (APT) involves the epicutaneous application of intact protein allergens in a diagnostic patch test setting with an evaluation of the induced eczematous skin lesions after 24 to 72 hours. The APT targets the cellular component of AE and helps round out the AE test spectrum. As a number of apparently minor test modifications greatly influence the sensitivity, specificity, and reproducibility of the APT, the European Task Force on Atopic Dermatitis (ETFAD) has developed a standardized APT technique. It consists of purified allergen preparations in petrolatum, applied in 12-mm diameter Finn chambers mounted on Scanpor tape to non-irritated, non-abraded, or tape-stripped skin of the upper back. The APT is read at 48 and 72 hours according to the test criteria and reading key of the ETFAD for appearance of erythema, and number and distribution pattern of the papules. In contrast with skin prick tests, the APT might even detect a relevant sensitization in the absence of specific IgE. Many studies have been undertaken to objectify the sensitivity and specificity of the APT to show its diagnostic use in clinical practice.

Advisory Committees↗
PubMed1996

Immunohistological analysis of 'negative' patch test sites in atopic dermatitis.

BACKGROUND: Variable results have been obtained when patients with atopic dermatitis (AD),) have been patch tested with allergens known to produce a positive prick test. The significance of patch test results in our understanding of the pathogenesis of AD therefore remains questionable. OBJECTIVE: This study was designed to determine the relevance of either positive or negative patch test results in relation to the expression of cell mediated immunity to allergens in patients with AD. METHODS: Thirty-five patients with AD exhibiting patch test positivity to one or more aeroallergens on 'tape stripped' areas of the back were retested without prior tape stripping. Nine patients again showed positivity to one or more allergens while 26 failed to show positive reactions. In six of the positive patients both positive and negative patch tests were observed. Skin biopsies were taken from these matched positive and negative patch test sites as well as from an area of uninvolved skin. Samples were frozen and cryostat sections were analysed with immunohistological techniques using monoclonal antibodies to investigate the distribution of immunocompetent cells. RESULTS: All positive patch tests exhibited characteristics of a cell mediated immune response. The negative patch test sites were also found to contain evidence of mononuclear cell infiltration. Both negative and positive patch test sites showed significantly greater proportions of T cells compared to uninvolved skin. No increase in numbers of RFD1 positive and RFD7 positive macrophages were observed in either positive or negative patch test sites. Expression of CD23 by CD1 positive Langerhans cells was raised in both negative and positive patch tests compared to uninvolved areas. A significant increase in the population (RFD7+, CD23+) was seen in positive patch test sites compared to uninvolved skin. An increase in the proportion of RFD1 positive cells expressing CD23 was also seen in both negative and positive patch tests compared to uninvolved skin. CONCLUSIONS: This paper demonstrates that immunological reactions are promoted at 'non-tape stripped' patch test sites where no clinical evidence of reactivity is seen. Together the data demonstrate that the presence of systemic cell mediated immunity to specific allergens identified in patients by positive patch test, may also be present when no clinical signs are seen at the patch test site.

Adolescent↗
PubMed1975

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.

Adult↗
PubMed1989

The relationship between positive aeroallergen patch test reactions and aeroallergen exacerbations of atopic dermatitis.

Previously we have demonstrated that patient contact with specific aeroallergens can cause flares of atopic dermatitis. In this study we report six additional cases that further document the relationship between positive aeroallergen patch test reactions and aeroallergen exacerbation of atopic dermatitis. In total, we have seen 18 patients (8 male, 10 female; ages 1-54 years) who have noted marked improvement in their skin symptomatology when antigen elimination (or moderation) was instituted as part of their general management. Delineation of inciting allergen was accomplished by a combination of prick tests and patch tests to aeroallergens. On prick testing all patients had markedly positive immediate wheal and flare reactions to a variety of aeroallergen extracts (tree, grass, and weed pollen, house dust mite, animal protein, and mold spores). The same patients were subsequently patch tested on uninvolved, nonabraded skin with allergen extracts at the same concentrations that had given positive prick tests. Patch tests were applied for 48 hr, removed, and interpreted at 48 and 72 hr. Patients reacted to specific aeroallergens with an eczematous eruption at 48 or 72 hr or at both time points. Positive delayed cutaneous reactions correlated strongly with aeroallergens identified in the patient's environment and/or suspected by the patients as inducers of dermatitis. Delayed cutaneous reactions were negative to allergens not historically relevant. Avoidance of aeroallergens that elicited an eczematous reaction at patch test sites resulted in marked improvement or resolution of dermatitis in all patients. Environmental rechallenge with incriminated allergens resulted in flares of dermatitis. We conclude that aeroallergen contact plays an important role in select patients with atopic dermatitis and that the responsible allergens can be elucidated by a combination of prick and patch tests.

Aerosols↗
PubMed1989

Reproducibility of patch test results: comparison of TRUE Test and Finn Chamber test results.

To evaluate the reproducibility of patch test results, duplicate patch test series comprising 12 allergens were simultaneously applied to either side of the back in 63 patients by the use of a newly developed patch test system, TRUE Test. When a positive test result occurred on only one side of the back, it was regarded as nonreproducible. For evaluation of the concordance of test reactions between the TRUE Test and the Finn Chamber test, the same 12 allergens mixed in petrolatum were also applied to the upper back according to the Finn Chamber technique. The reproducibility of TRUE Test results was compared with the reproducibility of the Finn Chamber test in 76 other patients. The concordance of positive reactions between the two tests was 57%, somewhat lower than in recently published studies. The percentage of nonreproducible positive results was more than twice as high with Finn Chambers, (22 of 58 positive reactions, or 37.9%) as with the TRUE Test (5 of 28 reactions, or 17.9%). However, this difference in reproducibility in the two test systems was not significant as determined by the chi 2 test (p less than 0.05).

Allergens↗
PubMed1982

Improvement of patch test allergen exposure by short-term local pressure.

Since false-negative results in patch testing may be due to insufficient skin contact with the allergen during exposure, we tried a modified test method by initially applying standardized pressure (10-kg sand bag for 15 min) on the test patches. Tests were simultaneously performed in 50 patients with and without local pressure. Comparing the results of both methods and (in some cases) to those after stripping the horny layers, positive contact sensitivity reactions could more often be detected after initial application of pressure.

Allergens↗
PubMed1998

Oxidation of resin acids in colophony (rosin) and its implications for patch testing.

Commercial preparations of colophony (rosin) used for patch testing are made from unmodified rosin in pet. and may be stored for some considerable time before being used. This would be satisfactory if the composition and dermatological activity of the preparations were both reproducible and stable, but investigations by the authors have shown that the resin acids undergo progressive and substantial oxidation and that the dermatological activity of the preparations increases significantly with time. This may be a cause of inconsistent patch test results unless the composition can be stabilized. Gas liquid chromatography (GLC) analysis of a raw rosin sample and its commercial patch test preparation has shown that they both contained the same resin acids, but the concentration of the abietic type resin acids was found to be lower in the patch test preparations. The degradation of resin acids is due to their atmospheric oxidation, which may occur during the preparation and storage of the commercial rosin patch test preparation. The susceptibility of individual resin acids to atmospheric oxidation was demonstrated by analysing a sample of raw Portuguese gum rosin, which was then left exposed to air and light. Most of the resin acids were found to undergo oxidation at a rate which gradually diminished. More importantly, it is presumed that the concentration of oxidized resin acids increased correspondingly, and these have been shown to be more dermatologically active than the unoxidised resin acids. The rate of decrease of resin acid concentration was found to be in the following order: neoabietic>levopimaric and palustric>abietic>dehydroabetic acid. The pimaric type resin acids were found to be relatively inert to atmospheric oxidation when compared with the abietic type resin acids. Patch testing with the resulting partly oxidized Portuguese rosin produced positive reactions at a 35% higher frequency than the raw Portuguese rosin. The study demonstrates that the allergic potential of unmodified rosin may increase with exposure to air and light. It is therefore recommended that rosin preparations are analysed routinely as part of a quality control programme, which will enable better validation and comparison of patch test results from different dermatological centres. Since the oxidized resin acids are the main allergens in unmodified rosin, it is important that the concentration of the oxidized resin acids is kept high as well as constant in commercial patch test preparations.

Allergens↗
PubMed1979

"Reactions" to standard patch test materials.

Twelve compounds tested by closed patch test at recommended concentrations produced numerous "Fallse positive" non-allergenic reactions in a panel of 100 vollunteers. These results indicate the need for further basic studies to determine appropriate non-irritating concentrations of materials used in biagnostic patch testing for contact allergy.

Adult↗
PubMed1995

Chloromethylisothiazolone/methylisothiazolone (CMI/MI) use test with a shampoo on patch-test-positive subjects. Results of a multicentre double-blind crossover trial.

A randomized, multicentre, double-blind, 2-period crossover study with 2 shampoos was performed on subjects patch-test-positive to 100 ppm CMI/MI. One shampoo was preserved with 15 ppm a.i. CMI/MI, the other with 0.3% imidazolidinyl urea (IU). 27 subjects from 5 European dermatology clinics participated. 1 subject discontinued use after severe adverse reactions to the CMI/MI-preserved shampoo and did not evaluate the other shampoo. Another 2 subjects developed moderate symptoms with the CMI/MI-preserved shampoo and discontinued its use, but tolerated the IU-preserved shampoo for the full 2-week period. 2 subjects discontinued use after 1 or 2 washes after severe adverse reactions to the IU-preserved shampoo. 1 of these subjects tolerated the CMI/MI-preserved shampoo for 2 weeks without any untoward effects. However, the majority of subjects had negative findings on the scalp, face, neck, and hands for both shampoos. The physicians' global evaluation data indicated that shampoo with CMI/MI caused fewer skin problems than shampoo with IU (38% versus 27%, n.s.), with over 1/3 of the subjects (35%) having no skin problems with either preservative. The current study showed that most subjects previously sensitized to CMI/MI can successfully use shampoo preserved with CMI/MI. Since some subjects previously sensitized to CMI/MI, or possibly to IU, may develop clinical reactions, it would still be prudent for the clinician to advise alternative products to patients with sensitivity to a shampoo or cosmetic ingredient. Full ingredient labelling will ensure that this is possible. As the overall rate of adverse effects in sensitized individuals was low, studies of this nature should also be conducted for other allergens.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-Over Studies↗
PubMed1989

Aeroallergen contact can exacerbate atopic dermatitis: patch tests as a diagnostic tool.

Previous studies have documented that atopic dermatitis can worsen when patients ingest specific foods to which they are sensitive. In this article we demonstrate that patient contact with specific aeroallergens can cause flares of atopic dermatitis. Marked improvement in skin symptoms was noted when 12 patients (eight males and four females; ages, 1 to 54 years) were removed from their unusual environment. In response to prick tests, these patient had markedly positive, immediate wheel-and-flare reactions to a variety of aeroallergen extracts (tree, grass, and weed pollen; house dust mite; animal protein; and mold spores). The same patients were subsequently patch tested on uninvolved, nonabraded skin with the allergen extracts that had yielded positive prick tests. Patch tests were applied for 48 hours, removed, and interpreted 24 hours later. The patients reacted to specific aeroallergens with an eczematous eruption at 48 and 72 hours. Positive delayed cutaneous reactions correlated strongly with aeroallergens identified in the patient's environment or suspected by the patients as provocateurs of their atopic dermatitis. Delayed cutaneous reactions were negative to allergens not historically relevant. Continued avoidance of aeroallergens that elicited an eczematous reaction at patch test sites resulted in marked improvement or resolution of dermatitis in all patients. We conclude that aeroallergen contact plays an important role in select patients with atopic dermatitis.

Adult↗