The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
S Schauder - One of the best experts on this subject based on the ideXlab platform.
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Phototoxische und photoallergische Reaktionen
Der Hautarzt, 2013Co-Authors: N.j. Neumann, S SchauderAbstract:Many artificial or naturally occurring substances are included under the term photosensitizer. After ultraviolet (UV) exposure such agents can lead to increased photosensitivity and subsequently to phototoxic or photoallergic reactions in the skin. From clinical observations and comprehensive studies typical reaction patterns can be deduced which can clarify the difference between phototoxic and photoallergic dermatitis.An illuminated epicutaneous Test based on conventional epicutaneous Tests, the Photopatch Test, was developed as a screening method for identification of photosensitizers. The diagnostic specificity and sensitivity of the Test is comparable to conventional epicutaneous Testing. If possible photosensitizers do not cause any relevant reactions with the Photopatch Test, other Test procedures, such as the photoprick, photoscratch and illuminated intracutaneous Tests are available. If the actual photosensitizer is not the Test substance but a metabolite of the Test substance, a systemic photoprovocation Test can be indicated. Zahlreiche künstlich hergestellte oder natürlich vorkommende Substanzen werden unter der Bezeichnung „Photosensibilisatoren“ zusammengefasst. Nach UV-Exposition können derartige Agenzien in der Haut zu einer erhöhten Photosensitivität und damit zu phototoxischen oder photoallergischen Reaktionen führen. Durch klinische Beobachtungen und umfangreiche Studien konnten typische Reaktionsmuster abgeleitet werden, die den Unterschied zwischen phototoxischen und photoallergischen Dermatitiden verdeutlichen. Als Screeningmethode zur Identifikation von Photosensibilisatoren wurde in Anlehnung an die konventionelle EpikutanTestung ein belichteter EpikutanTest, der PhotopatchTest, entwickelt. In Bezug auf seine diagnostische Spezifität und Sensitivität ist dieser durchaus mit der konventionellen EpikutanTestung vergleichbar. Falls mögliche Photosensibilisatoren im PhotopatchTest keine relevanten Reaktionen hervorrufen, stehen noch weitere Testverfahren, der Photoprick-, der Photoscratch- und der belichtete IntrakutanTest, zur Verfügung. Sollte jedoch der eigentliche Photosensibilisator nicht die Testsubstanz selber, sondern ein Metabolit der Testsubstanz sein, so kann eine systemische PhotoprovokationsTestung indiziert sein.
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Phototoxische und photoallergische Reaktionen
Der Hautarzt, 2013Co-Authors: N.j. Neumann, S SchauderAbstract:Zahlreiche künstlich hergestellte oder natürlich vorkommende Substanzen werden unter der Bezeichnung „Photosensibilisatoren“ zusammengefasst. Nach UV-Exposition können derartige Agenzien in der Haut zu einer erhöhten Photosensitivität und damit zu phototoxischen oder photoallergischen Reaktionen führen. Durch klinische Beobachtungen und umfangreiche Studien konnten typische Reaktionsmuster abgeleitet werden, die den Unterschied zwischen phototoxischen und photoallergischen Dermatitiden verdeutlichen. Als Screeningmethode zur Identifikation von Photosensibilisatoren wurde in Anlehnung an die konventionelle EpikutanTestung ein belichteter EpikutanTest, der PhotopatchTest, entwickelt. In Bezug auf seine diagnostische Spezifität und Sensitivität ist dieser durchaus mit der konventionellen EpikutanTestung vergleichbar. Falls mögliche Photosensibilisatoren im PhotopatchTest keine relevanten Reaktionen hervorrufen, stehen noch weitere Testverfahren, der Photoprick-, der Photoscratch- und der belichtete IntrakutanTest, zur Verfügung. Sollte jedoch der eigentliche Photosensibilisator nicht die Testsubstanz selber, sondern ein Metabolit der Testsubstanz sein, so kann eine systemische PhotoprovokationsTestung indiziert sein. Many artificial or naturally occurring substances are included under the term photosensitizer. After ultraviolet (UV) exposure such agents can lead to increased photosensitivity and subsequently to phototoxic or photoallergic reactions in the skin. From clinical observations and comprehensive studies typical reaction patterns can be deduced which can clarify the difference between phototoxic and photoallergic dermatitis.An illuminated epicutaneous Test based on conventional epicutaneous Tests, the Photopatch Test, was developed as a screening method for identification of photosensitizers. The diagnostic specificity and sensitivity of the Test is comparable to conventional epicutaneous Testing. If possible photosensitizers do not cause any relevant reactions with the Photopatch Test, other Test procedures, such as the photoprick, photoscratch and illuminated intracutaneous Tests are available. If the actual photosensitizer is not the Test substance but a metabolite of the Test substance, a systemic photoprovocation Test can be indicated.
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Photopatch Testing : The 12-year experience of the German, Austrian, and Swiss Photopatch Test Group
Journal of The American Academy of Dermatology, 2000Co-Authors: Erhard Holzle, Norbert J. Neumann, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm 2 UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticlor, wood tar, balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.
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Photopatch Testing: the 5-year experience of the German, Austrian, and Swiss Photopatch Test Group.
Journal of the American Academy of Dermatology, 1991Co-Authors: Erhard Holzle, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, N Neumann, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm2UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticolar, wood balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.
Bo Niklasson - One of the best experts on this subject based on the ideXlab platform.
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Photoallergic Contact Dermatitis to Sunscreens Containing Oxybenzone in La Plata, Argentina.
Actas dermo-sifiliograficas, 2018Co-Authors: Juan Pedro Russo, Adriana Ipiña, J.f. Palazzolo, A.b. Cannavó, Rubén D. Piacentini, Bo NiklassonAbstract:Abstract Background Photoallergic contact dermatitis (PACD) to oxybenzone was reported for the first time in 1980. Oxybenzone is the most common photoallergen in the United States and Canada and the fourth most common .in Europe. There are no studies or data on the prevalence of oxybenzone PACD in Argentina. Objective To determine the proportion of photosensitive patients with PACD to oxybenzone. Methods We conducted a descriptive cross-sectional study of 35 patients with photosensitivity reactions confirmed by Photopatch Testing at the Research Center of Hospital Publico San Martin in La Plata, Argentina, in 2015 and 2016. Results PACD was identified in 6 patients (17.14%). Five of these (14.28%) had at least one positive reaction to oxybenzone in the Photopatch Test; 4 had a reaction at irradiated sites only (5 J/cm2 UVA) and one had a reaction at both irradiated and nonirradiated sites. Conclusions PACD to sunscreens containing oxybenzone is common and is probably underdiagnosed due to a lack of confirmation by Photopatch Tests or other diagnostic tools. Sensitization rates vary according to region and are influenced by sunscreen ingredients and variations in the use of sunscreen products, cosmetics, and topical drugs.
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Photoallergic Contact Dermatitis to Sunscreens Containing Oxybenzone in La Plata, Argentina.
Actas dermo-sifiliograficas, 2018Co-Authors: Juan Pedro Russo, Adriana Ipiña, J.f. Palazzolo, A.b. Cannavó, Rubén D. Piacentini, Bo NiklassonAbstract:Abstract Background Photoallergic contact dermatitis (PACD) to oxybenzone was reported for the first time in 1980. Oxybenzone is the most common photoallergen in the United States and Canada and the fourth most common .in Europe. There are no studies or data on the prevalence of oxybenzone PACD in Argentina. Objective To determine the proportion of photosensitive patients with PACD to oxybenzone. Methods We conducted a descriptive cross-sectional study of 35 patients with photosensitivity reactions confirmed by Photopatch Testing at the Research Center of Hospital Publico San Martin in La Plata, Argentina, in 2015 and 2016. Results PACD was identified in 6 patients (17.14%). Five of these (14.28%) had at least one positive reaction to oxybenzone in the Photopatch Test; 4 had a reaction at irradiated sites only (5 J/cm2 UVA) and one had a reaction at both irradiated and nonirradiated sites. Conclusions PACD to sunscreens containing oxybenzone is common and is probably underdiagnosed due to a lack of confirmation by Photopatch Tests or other diagnostic tools. Sensitization rates vary according to region and are influenced by sunscreen ingredients and variations in the use of sunscreen products, cosmetics, and topical drugs.
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Photopatch Testing: recommendations for a European Photopatch Test baseline series
Contact dermatitis, 2013Co-Authors: Margarida Gonçalo, A.c. Kerr, Derk P Bruynzeel, Norbert J. Neumann, James Ferguson, An Goossens, Annie Bonevalle, Ana Giménez-arnau, Mario Lecha, Bo NiklassonAbstract:In order to establish a consensus recommendation for performing Photopatch Testing, a Photopatch Test taskforce group was established under the joint umbrella of the European Society for Contact Dermatitis and the European Society for Photodermatology in 2000. After proposing the most adequate methodology in 2004 and completing a European multicentre Photopatch Test study in 2011, this taskforce is recommending a list of photoallergens that should form part of a baseline series for Photopatch Testing in Europe. It contains mainly ultraviolet filters and drugs, mostly non-steroidal anti-inflammatory drugs. The choice of chemicals was based on the results of a recent multicentre study, previous published cases of photoallergy, and use of the substances in the European market. It is suggested that an extended list of photoallergens should be Photopatch Tested in selected cases, along with patients' own products. Two contact allergens, cinnamyl alcohol and decyl glucoside, should be simultaneously patch Tested in order to clarify Photopatch and patch Test reactions, respectively, to ketoprofen and methylene bis-benzotriazolyl tetramethylbutylphenol (Tinosorb M™).
Erhard Holzle - One of the best experts on this subject based on the ideXlab platform.
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Photopatch Testing: a consensus methodology for Europe.
Journal of the European Academy of Dermatology and Venereology : JEADV, 2004Co-Authors: Derk P Bruynzeel, Erhard Holzle, James Ferguson, An Goossens, Margarida Gonçalo, Sally H. Ibbotson, Klaus Ejner Andersen, John S. C. English, M Lecha, P. LehmannAbstract:A group of interested European Contact Dermatologists/Photobiologists met to produce a consensus statement on methodology, Test materials and interpretation of Photopatch Testing. While it is recognized that a range of local variables operate throughout Europe, the underlying purpose of the work is to act as an essential preamble to a Pan European Photopatch Test Study focusing particularly on sunscreen chemicals.
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Photopatch Testing : The 12-year experience of the German, Austrian, and Swiss Photopatch Test Group
Journal of The American Academy of Dermatology, 2000Co-Authors: Erhard Holzle, Norbert J. Neumann, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm 2 UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticlor, wood tar, balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.
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Photopatch Testing: the 12-year experience of the German, Austrian, and Swiss Photopatch Test group.
Journal of the American Academy of Dermatology, 2000Co-Authors: Norbert J. Neumann, Erhard Holzle, Gerd Plewig, T Schwarz, R G Panizzon, R Breit, T Ruzicka, P. LehmannAbstract:In 1984, the German, Austrian, and Swiss Photopatch Test Group was founded to standardize the Photopatch Test procedure and to investigate photoallergic reactions, as well as the epidemiology of photoallergy, in central Europe. Therefore in a first Test period from 1985-1990, 32 Test substances were applied on the backs of patients suspected to be photosensitive. After evaluation of these data, some substances were dismissed, and others were additionally integrated into the Test tray. Thus a modified Test tray comprising 26 Test substances was used for the second Test period (1991-1997). According to the standard Photopatch Test procedure defined in the first Test period, the aim of this multicenter study was to apply compounds from the modified second Test tray to a large group of photosensitive patients. After evaluation of the second Test period (1991-1997), the outcome was compared with the results of the first period. On the basis of these results and influenced by concurrently published case reports, a third modified Photopatch Test tray has been established. After the application of a duplicate Test tray for 24 hours, one Test site was irradiated with 10 J/cm(2) UVA, and the other Test site served as the control area. Readings were performed immediately and 24, 48, and 72 hours after irradiation. Test reactions were qualitatively graded according to a 4-point scale and classified by the investigators of the participating centers. In 49 participating clinics 1261 Photopatch Tests were performed. All data were subjected to computer-assisted analysis by using a specially developed software to classify all positive Test reactions as plain contact or photoinduced reactions (nonspecific, toxic, or allergic photoreactions) and to define substance-specific reaction patterns. In Test period 1 data of 1129 patients were evaluated. From 2859 positive Test reactions, 28.6% were excluded as plain contact reactions, 71.4% were found to be photoinduced reactions, and 3.8% were classified as photoallergic. In Test period 2 data of 1261 patients were evaluated. One thousand four hundred fifteen positive Test reactions were observed, and of these, 28.7% were excluded as plain contact reactions, 71.3% were classified as photoinduced reactions, and 8.1% were classified as photoallergic reactions. In both Test periods nonsteroidal anti-inflammatory drugs, disinfectants, and phenothiazines represented the leading photoallergens in the evaluated central European region. By using computer-assisted reaction pattern analysis, substance-specific reaction patterns could be distinguished. These substance-specific reaction patterns comprised 4 main categories: the well-known decrescendo (phototoxic) and crescendo (photoallergic) reaction patterns, as well as a combined and a plateau pattern. The Test modification after the first Test period led to a notably reduced number of positive (mainly nonphotoallergic and thus nonrelevant) Test reactions per patient in the second Test period (from 2.6 to 1.1). In contrast, the percentage of photoallergic reactions increased significantly from 3.8% to 8.1% of all positive Test reactions. Test modifications after the first Test period led to a remarkably improved specificity of the Photopatch Test. Furthermore, substance-specific reaction patterns observed in Test period 1 were confirmed in Test period 2.
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Photosensitivity induced by quinidine sulfate: experimental reproduction of skin lesions.
Photodermatology photoimmunology & photomedicine, 1992Co-Authors: Erhard Holzle, Gerd Plewig, P LehmannAbstract:A case of quinidine sulfate-induced photodermatitis is reported. The photosensitive reaction to quinidine sulfate was reproducible in the Photopatch Test and after oral intake plus ultraviolet A (UVA) irradiation. Eczematous dermatitis was provoked after intradermal injection of in vitro UVA-irradiated quinidine sulfate only in the presence of patient's serum. The clinical picture and histology suggest an allergic reaction. The photobinding of quinidine sulfate to a potential carrier protein in skin or serum seems to be of crucial importance for this type of photodermatitis. Quinidine sulfate is frequently used as an antiarrhythmic drug. Its potential as a photosensitizer should always be considered.
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Photopatch Testing: the 5-year experience of the German, Austrian, and Swiss Photopatch Test Group.
Journal of the American Academy of Dermatology, 1991Co-Authors: Erhard Holzle, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, N Neumann, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm2UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticolar, wood balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.
James Ferguson - One of the best experts on this subject based on the ideXlab platform.
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Photopatch Testing: recommendations for a European Photopatch Test baseline series
Contact dermatitis, 2013Co-Authors: Margarida Gonçalo, A.c. Kerr, Derk P Bruynzeel, Norbert J. Neumann, James Ferguson, An Goossens, Annie Bonevalle, Ana Giménez-arnau, Mario Lecha, Bo NiklassonAbstract:In order to establish a consensus recommendation for performing Photopatch Testing, a Photopatch Test taskforce group was established under the joint umbrella of the European Society for Contact Dermatitis and the European Society for Photodermatology in 2000. After proposing the most adequate methodology in 2004 and completing a European multicentre Photopatch Test study in 2011, this taskforce is recommending a list of photoallergens that should form part of a baseline series for Photopatch Testing in Europe. It contains mainly ultraviolet filters and drugs, mostly non-steroidal anti-inflammatory drugs. The choice of chemicals was based on the results of a recent multicentre study, previous published cases of photoallergy, and use of the substances in the European market. It is suggested that an extended list of photoallergens should be Photopatch Tested in selected cases, along with patients' own products. Two contact allergens, cinnamyl alcohol and decyl glucoside, should be simultaneously patch Tested in order to clarify Photopatch and patch Test reactions, respectively, to ketoprofen and methylene bis-benzotriazolyl tetramethylbutylphenol (Tinosorb M™).
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A European multicentre Photopatch Test study
The British journal of dermatology, 2012Co-Authors: A.c. Kerr, James Ferguson, Ann K. Haylett, Lesley E. Rhodes, Henri Adamski, Agustín Alomar, Esther Serra, Christina Antoniou, François Aubin, M. ViganAbstract:The two most common agent groups currently responsible for photoallergic contact dermatitis (PACD) are organic ultraviolet (UV) absorbers in sunscreens and topical nonsteroidal anti-inflammatory drugs (NSAIDs). However, availability of information on the photoallergenic potential of these agents is scarce. To obtain current information on the frequency of PACD to 19 organic UV absorbers and five topical NSAIDs, including newer agents, in common usage in Europe. A prospective, multicentre Photopatch Test study was conducted with 1031 patients attending for investigation of suspected PACD in 30 centres across 12 European countries. A total of 346 PACD reactions in 200 (19·4%) subjects occurred. PACD was most commonly caused by the topical NSAIDs, ketoprofen (128 subjects) and etofenamate (59 subjects). Of the organic UV absorbers, octocrylene, benzophenone-3 and butyl methoxydibenzoylmethane most frequently elicited PACD. The 'newer' organic sunscreen absorbers rarely led to PACD. There appeared to be an association between the agents ketoprofen, octocrylene and benzophenone-3, with several subjects developing PACD to two or all three agents concomitantly. Allergic contact dermatitis (ACD) was less commonly observed than PACD, comprising 55 reactions in 47 (5%) subjects. Irritant reactions and photoaugmentation and photoinhibition of ACD occurred infrequently. The European multicentre Photopatch Test study has provided current information on the relative frequency of PACD to common photoallergens. Such data will be of value when deciding on which agents to include in a future European 'baseline' Photopatch Test series. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.
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Photopatch Testing negative in systemic quinine phototoxicity
Photodermatology Photoimmunology and Photomedicine, 2010Co-Authors: A.c. Kerr, Mohammed Shareef, Robert S. Dawe, James FergusonAbstract:Drug-induced phototoxicity can be caused by topical or systemic agents and is diagnosed on the basis of clinical history, examination and appropriate investigations. Photopatch Testing is the investigation of choice for topical photocontact allergic dermatitis, but its use in drug-induced phototoxicity has not been validated. We retrospectively analyzed the results of Photopatch Testing to the drug quinine sulfate in three patients in whom a diagnosis of drug-induced phototoxicity to this agent had been made. None of the three patients had positive Photopatch Test reactions at any time point. This demonstrates that in our patients, Photopatch Testing to quinine sulfate was not a useful additional investigation for diagnosing drug-induced phototoxicity.
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Photoallergic contact dermatitis.
Photodermatology photoimmunology & photomedicine, 2010Co-Authors: A.c. Kerr, James FergusonAbstract:Background: Photoallergic contact dermatitis (PACD) presents in patients after certain exogenous agents come into contact with the skin in the presence of ultraviolet and/or visible light. The best method currently available for investigating PACD is Photopatch Testing. However, Photopatch Testing as an investigation is under-used by clinicians, and therefore PACD may go undetected in many patients. Purpose: To highlight the importance of PACD and Photopatch Testing when investigating patients with a photo-exposed site dermatosis. Method: A comprehensive review of the available literature relating to PACD and Photopatch Testing. Results: Experimental evidence suggests that PACD is a delayed type hypersensitivity reaction. Various agents have been historically shown to cause PACD, but currently the most common photosensitizers are sunscreens and topical non-steroidal anti-inflammatory drugs. Photopatch Testing has in the past been subject to differing methodologies; however, a European consensus methodology now exists and should allow a greater comparison of results across centres. As chemical, pharmaceutical, and cosmetic industries produce new agents, Photopatch Testing of such agents in humans before release in the marketplace may prevent widespread contact with potent photosensitizers. It will also be important for ongoing multi-centre studies of existing agents to be conducted in order to keep the Photopatch Test batteries used by clinicians investigating PACD up to date.
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Can a positive Photopatch Test be elicited by subclinical irritancy or allergy plus suberythemal UV exposure
Contact dermatitis, 2004Co-Authors: Paula E. Beattie, Robert S. Dawe, James Ferguson, N. J. Traynor, Jeremy Woods, Sally H. IbbotsonAbstract:Photopatch Test (PhPT) interpretation is difficult and clinical relevance is not always apparent. A positive PhPT may reflect photocontact allergy or phototoxicity. We hypothesized that it may also reflect the additive or synergistic effects of a suberythemal reaction to a contact irritant [e.g. sodium lauryl sulfate (SLS)] or allergen (e.g. nickel) and suberythemal UV exposure. 10 nickel allergic volunteers had duplicate SLS and nickel series applied on either side of the back for 24 h and 48 h, respectively. After removal, one side was irradiated with 5 J/cm 2 UVA or the dose below the minimal erythema dose for solar-simulated radiation (SSR). The minimal irritancy dose (MID) for SLS and the minimal allergenic dose (MAD) for nickel were determined visually and objectively by erythema meter. While photoaugmentation of subclinical contact allergy or irritancy occurred in some subjects, photosuppression occurred in roughly an equal number. UVA changed the nickel MAD at 48 h in 2 of 5 volunteers but not the SLS MID. SSR changed the nickel MAD in 4 of 5 and the SLS MID in 3 of 5. 2 subjects (none after UVA) showed erythema only in the irradiated set of patches, which could have been interpreted as a positive PhPT. We have demonstrated photoaugmentation and photosuppression of contact allergy and irritancy, which could result in false-positive or false-negative interpretation of PhPTs.
Gerd Plewig - One of the best experts on this subject based on the ideXlab platform.
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Photopatch Testing : The 12-year experience of the German, Austrian, and Swiss Photopatch Test Group
Journal of The American Academy of Dermatology, 2000Co-Authors: Erhard Holzle, Norbert J. Neumann, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm 2 UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticlor, wood tar, balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.
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Photopatch Testing: the 12-year experience of the German, Austrian, and Swiss Photopatch Test group.
Journal of the American Academy of Dermatology, 2000Co-Authors: Norbert J. Neumann, Erhard Holzle, Gerd Plewig, T Schwarz, R G Panizzon, R Breit, T Ruzicka, P. LehmannAbstract:In 1984, the German, Austrian, and Swiss Photopatch Test Group was founded to standardize the Photopatch Test procedure and to investigate photoallergic reactions, as well as the epidemiology of photoallergy, in central Europe. Therefore in a first Test period from 1985-1990, 32 Test substances were applied on the backs of patients suspected to be photosensitive. After evaluation of these data, some substances were dismissed, and others were additionally integrated into the Test tray. Thus a modified Test tray comprising 26 Test substances was used for the second Test period (1991-1997). According to the standard Photopatch Test procedure defined in the first Test period, the aim of this multicenter study was to apply compounds from the modified second Test tray to a large group of photosensitive patients. After evaluation of the second Test period (1991-1997), the outcome was compared with the results of the first period. On the basis of these results and influenced by concurrently published case reports, a third modified Photopatch Test tray has been established. After the application of a duplicate Test tray for 24 hours, one Test site was irradiated with 10 J/cm(2) UVA, and the other Test site served as the control area. Readings were performed immediately and 24, 48, and 72 hours after irradiation. Test reactions were qualitatively graded according to a 4-point scale and classified by the investigators of the participating centers. In 49 participating clinics 1261 Photopatch Tests were performed. All data were subjected to computer-assisted analysis by using a specially developed software to classify all positive Test reactions as plain contact or photoinduced reactions (nonspecific, toxic, or allergic photoreactions) and to define substance-specific reaction patterns. In Test period 1 data of 1129 patients were evaluated. From 2859 positive Test reactions, 28.6% were excluded as plain contact reactions, 71.4% were found to be photoinduced reactions, and 3.8% were classified as photoallergic. In Test period 2 data of 1261 patients were evaluated. One thousand four hundred fifteen positive Test reactions were observed, and of these, 28.7% were excluded as plain contact reactions, 71.3% were classified as photoinduced reactions, and 8.1% were classified as photoallergic reactions. In both Test periods nonsteroidal anti-inflammatory drugs, disinfectants, and phenothiazines represented the leading photoallergens in the evaluated central European region. By using computer-assisted reaction pattern analysis, substance-specific reaction patterns could be distinguished. These substance-specific reaction patterns comprised 4 main categories: the well-known decrescendo (phototoxic) and crescendo (photoallergic) reaction patterns, as well as a combined and a plateau pattern. The Test modification after the first Test period led to a notably reduced number of positive (mainly nonphotoallergic and thus nonrelevant) Test reactions per patient in the second Test period (from 2.6 to 1.1). In contrast, the percentage of photoallergic reactions increased significantly from 3.8% to 8.1% of all positive Test reactions. Test modifications after the first Test period led to a remarkably improved specificity of the Photopatch Test. Furthermore, substance-specific reaction patterns observed in Test period 1 were confirmed in Test period 2.
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Photosensitivity induced by quinidine sulfate: experimental reproduction of skin lesions.
Photodermatology photoimmunology & photomedicine, 1992Co-Authors: Erhard Holzle, Gerd Plewig, P LehmannAbstract:A case of quinidine sulfate-induced photodermatitis is reported. The photosensitive reaction to quinidine sulfate was reproducible in the Photopatch Test and after oral intake plus ultraviolet A (UVA) irradiation. Eczematous dermatitis was provoked after intradermal injection of in vitro UVA-irradiated quinidine sulfate only in the presence of patient's serum. The clinical picture and histology suggest an allergic reaction. The photobinding of quinidine sulfate to a potential carrier protein in skin or serum seems to be of crucial importance for this type of photodermatitis. Quinidine sulfate is frequently used as an antiarrhythmic drug. Its potential as a photosensitizer should always be considered.
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Photopatch Testing: the 5-year experience of the German, Austrian, and Swiss Photopatch Test Group.
Journal of the American Academy of Dermatology, 1991Co-Authors: Erhard Holzle, S Schauder, Bernhard Przybilla, B. Hausen, H. Hönigsmann, A. Bircher, N Neumann, Gerd PlewigAbstract:A cooperative Photopatch Test study was conducted by 45 dermatologic centers in Austria, Germany, and Switzerland. Results obtained from 1985 to 1990 are presented. A standard Photopatch Test tray of 32 substances was applied to the back of patients with suspected photosensivity. After applications for 24 hours, Test sites were irradiated with 10 joules/cm2UVA. Unirradiated controls were included. Readings were performed immediately and 24, 48, and 72 hours after irradiation; responses were qualitatively graded on a 4-point scale. All data were stored and processed by a computer. With computer-assisted analysis of reaction patterns photoallergic reactions were identified and distinguished from phototoxic reactions. Data of 1129 patients were evaluated. Among a total of 2859 positive Test reactions in 870 patients, 2041 in 778 patients were found to be photoinduced and 818 in 413 patients were contact reactions; 108 reactions in 83 patients were classified as photoallergic. Nonsteroidal anti-inflammatory drugs, disinfectants, sunscreens, phenothiazines, and fragrances caused most often photoallergic reactions. Many unspecific phototoxic reactions were induced by tiaprofenic acid, promethazine, carprofen, chlorpromazine, fenticolar, wood balsam of Peru, and perfumes. Despite the distinction between photoallergic and phototoxic responses, many Test reactions lacked relevance for the patients' dermatoses.