Contact Dermatitis • Contact Points EXPIRED TRUE TEST® FOR PATCH TESTING • RODRIGUES BARATA ET AL.
Can expired TRUE Test® be used for patch testing? 1 ´ Ana Rita Rodrigues Barata1 , Elisa Haroun-D´ıaz2 and Luis Conde-Salazar Gomez 1 Occupational Dermatology Department, Instituto de Salud Carlos III, Ciudad Universitaria, U. Complutense Madrid, 28040 Madrid, Spain and 2 Fundacion ´
´ Jimenez D´ıaz, Allergy Department, 28040 Madrid, Spain doi:10.1111/cod.12175
Key words: allergic contact dermatitis; non-invasive measuring methods; patch test.
Case Report Patch testing is a method for diagnosing allergic contact dermatitis, and the best way to differentiate it from irritant contact dermatitis (1). As part of the Spanish Contact Dermatitis Society baseline series, the thin-layer rapiduse epicutaneous test, known as TRUE Test® (TT), is widely used (2–4). With the aim of studying the diagnostic capacity of expired TRUE Test® panels, a prospective study on consecutive patients attending our occupational dermatology department during February 2013 was conducted. In all patients, three TRUE Tests® with different expiry dates (2011, 2012, and 2013) were applied. Also, according to the clinical history and occupation of each patient, patch testing with a specific series was performed. Patients signed an informed consent form before the study was performed. The patches were removed on D2, and readings were performed on D2 and D3. During the study period, a total of 11 patients were patch tested with three TRUE Tests® with different expiry dates: 2011, 2012, and 2013. In 9 of 11 patients, the same positive reactions, with identical intensities, were observed in the three TRUE Tests® (Fig. 1). In the remaining 2 patients, the same positive reactions were observed in the TRUE Tests® with expiry dates in 2012–2013, and negative results were obtained in the TRUE Test® in with an expiry date in 2011 (Table 1).
Discussion Clinicians often find themselves with allergens that have already expired. However, it is known that some
Correspondence: Ana Rita Rodrigues Barata, Occupational Dermatology ´ 8, Ciudad Universitaria, Department, Instituto de Salud Carlos III, Pabellon U. Complutense Madrid, 28040 Madrid, Spain. Tel: +605602647; Fax: +918224075/76. E-mail: [email protected] Conflicts of interest: The authors declare no conflict of interests.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Contact Dermatitis, 70, 376–388
a
b
Fig. 1. (a) Patient no. 1. (b) Patient no. 11.
allergens, such as fragrances or acrylates, once prepared in Finn Chambers®, are unstable with decreases in concentration, leading to false-negative results in patch testing (5, 6). The TRUE Test® manufacturer informed us that they did not have clinical trials evaluating the reliability of patch testing with expired units (24 months after the expiry date on the label), although they
381
Contact Dermatitis • Contact Points EXPIRED TRUE TEST® FOR PATCH TESTING • RODRIGUES BARATA ET AL.
Table 1. Patch test results Reactions Age No. Sex (years) Atopy Occupation
Location/evolution
TT 2011
TT 2012
TT 2013
1
F
51
No
Warehouseman
Hands/2 months
Caine mix ++ Myroxylon pereirae +
Caine mix ++ M. pereirae +
2
M
63
No
Metallurgist
Hands/6 months
Negative
3
M
57
No
Hands/1 month
Negative
4 5 6
F F F
33 62 46
No No No
Graphic arts worker Beautician Cleaning tasks Cleaning tasks
Cobalt + MCI/MI ++ Negative
Caine mix ++ M. pereirae + Neomicin + Cobalt + MCI/MI ++ Negative
Hands/1 month Hands/7 months Generalized/3 months
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Thiuram mix ++
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Thiuram mix +
7
M
29
No
Metallurgist
Generalized/24 months
Nickel sulfate ++ Cobalt ++ Carba mix ++ MCI/MI ++
Nickel sulfate + Cobalt ++ Carba mix ++ MCI/MI ++
8
F
35
Yes
Hands/3 months
Negative
Fragrance mix +
9 10
F F
49 46
No No
Textile manufacturer Cleaning tasks Cleaning tasks
Generalized/36 months Hands/1 month
11
F
45
No
Hospitality worker Hands/1 month
Fragrance mix ++ Nickel sulfate ++ Carba mix + Thiuram mix ++ MCI/MI ++
Fragrance mix ++ Nickel sulfate ++ Carba mix + Thiuram mix ++ MCI/MI ++
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Gold sodium thiosulfate + Nickel sulfate ++ Cobalt ++ Carba mix ++ MCI/MI ++ Thiuram mix ++ Fragrance mix + Fragrance mix + Carba mix + Thiuram mix ++ MCI/MI ++
F, female; M, male; MCI/MI, methylchloroisothiazolinone/methylisothiazolinone; TT, TRUE Test®.
mentioned that some non-volatile allergens are likely to be stable over long periods, even at room temperature. Thus, the question remains of whether performing patch testing with expired TRUE Tests® leads to false-negative results and a consequent failure to detect possible contact sensitization.
In conclusion, and given the results of this study, we believe that patch testing with expired TRUE Tests® can give true-positive results; nevertheless, the reliability of each individual allergen reaction is open to question.
References 1 Bruze M, Conde-Salazar L, Goossens A, Kanerva L, White I R. Thoughts on sensitizers in a standard patch test series. The European Society of Contact Dermatitis. Contact Dermatitis 1999: 41: 241–250. 2 Fischer T, Kreilg¨ard B, Maibach H I. The true value of the TRUE test for allergic contact dermatitis. Curr Allergy Asthma Rep 2001: 1: 316–322.
382
3 Militello G, Woo D K, Kantor J, Egan C L, Solotoff S A, Spiers E M, Stierstorfer M B, James W D. The utility of the TRUE test in a private practice setting. Dermatitis 2006: 17: 77–84. 4 Jerajani H R, Melkote S. Thin-layer rapid-use epicutaneous test (TRUE test). Indian J Dermatol Venereol Leprol 2007: 73: 292–295.
5 Mose K F, Andersen K E, Christensen L P. Stability of selected volatile contact allergens in different patch test chambers under different storage conditions. Contact Dermatitis 2012: 66: 172–179. 6 Mowitz M, Zimerson E, Svedman C, Bruze M. Stability of fragrance patch test preparations applied in test chambers. Br J Dermatol 2012: 167: 822–827.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Contact Dermatitis, 70, 376–388
Can expired TRUE Test® be used for patch testing? 1 ´ Ana Rita Rodrigues Barata1 , Elisa Haroun-D´ıaz2 and Luis Conde-Salazar Gomez 1 Occupational Dermatology Department, Instituto de Salud Carlos III, Ciudad Universitaria, U. Complutense Madrid, 28040 Madrid, Spain and 2 Fundacion ´
´ Jimenez D´ıaz, Allergy Department, 28040 Madrid, Spain doi:10.1111/cod.12175
Key words: allergic contact dermatitis; non-invasive measuring methods; patch test.
Case Report Patch testing is a method for diagnosing allergic contact dermatitis, and the best way to differentiate it from irritant contact dermatitis (1). As part of the Spanish Contact Dermatitis Society baseline series, the thin-layer rapiduse epicutaneous test, known as TRUE Test® (TT), is widely used (2–4). With the aim of studying the diagnostic capacity of expired TRUE Test® panels, a prospective study on consecutive patients attending our occupational dermatology department during February 2013 was conducted. In all patients, three TRUE Tests® with different expiry dates (2011, 2012, and 2013) were applied. Also, according to the clinical history and occupation of each patient, patch testing with a specific series was performed. Patients signed an informed consent form before the study was performed. The patches were removed on D2, and readings were performed on D2 and D3. During the study period, a total of 11 patients were patch tested with three TRUE Tests® with different expiry dates: 2011, 2012, and 2013. In 9 of 11 patients, the same positive reactions, with identical intensities, were observed in the three TRUE Tests® (Fig. 1). In the remaining 2 patients, the same positive reactions were observed in the TRUE Tests® with expiry dates in 2012–2013, and negative results were obtained in the TRUE Test® in with an expiry date in 2011 (Table 1).
Discussion Clinicians often find themselves with allergens that have already expired. However, it is known that some
Correspondence: Ana Rita Rodrigues Barata, Occupational Dermatology ´ 8, Ciudad Universitaria, Department, Instituto de Salud Carlos III, Pabellon U. Complutense Madrid, 28040 Madrid, Spain. Tel: +605602647; Fax: +918224075/76. E-mail: [email protected] Conflicts of interest: The authors declare no conflict of interests.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Contact Dermatitis, 70, 376–388
a
b
Fig. 1. (a) Patient no. 1. (b) Patient no. 11.
allergens, such as fragrances or acrylates, once prepared in Finn Chambers®, are unstable with decreases in concentration, leading to false-negative results in patch testing (5, 6). The TRUE Test® manufacturer informed us that they did not have clinical trials evaluating the reliability of patch testing with expired units (24 months after the expiry date on the label), although they
381
Contact Dermatitis • Contact Points EXPIRED TRUE TEST® FOR PATCH TESTING • RODRIGUES BARATA ET AL.
Table 1. Patch test results Reactions Age No. Sex (years) Atopy Occupation
Location/evolution
TT 2011
TT 2012
TT 2013
1
F
51
No
Warehouseman
Hands/2 months
Caine mix ++ Myroxylon pereirae +
Caine mix ++ M. pereirae +
2
M
63
No
Metallurgist
Hands/6 months
Negative
3
M
57
No
Hands/1 month
Negative
4 5 6
F F F
33 62 46
No No No
Graphic arts worker Beautician Cleaning tasks Cleaning tasks
Cobalt + MCI/MI ++ Negative
Caine mix ++ M. pereirae + Neomicin + Cobalt + MCI/MI ++ Negative
Hands/1 month Hands/7 months Generalized/3 months
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Thiuram mix ++
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Thiuram mix +
7
M
29
No
Metallurgist
Generalized/24 months
Nickel sulfate ++ Cobalt ++ Carba mix ++ MCI/MI ++
Nickel sulfate + Cobalt ++ Carba mix ++ MCI/MI ++
8
F
35
Yes
Hands/3 months
Negative
Fragrance mix +
9 10
F F
49 46
No No
Textile manufacturer Cleaning tasks Cleaning tasks
Generalized/36 months Hands/1 month
11
F
45
No
Hospitality worker Hands/1 month
Fragrance mix ++ Nickel sulfate ++ Carba mix + Thiuram mix ++ MCI/MI ++
Fragrance mix ++ Nickel sulfate ++ Carba mix + Thiuram mix ++ MCI/MI ++
Nickel sulfate ++ Negative Nickel sulfate ++ Cobalt ++ Gold sodium thiosulfate + Nickel sulfate ++ Cobalt ++ Carba mix ++ MCI/MI ++ Thiuram mix ++ Fragrance mix + Fragrance mix + Carba mix + Thiuram mix ++ MCI/MI ++
F, female; M, male; MCI/MI, methylchloroisothiazolinone/methylisothiazolinone; TT, TRUE Test®.
mentioned that some non-volatile allergens are likely to be stable over long periods, even at room temperature. Thus, the question remains of whether performing patch testing with expired TRUE Tests® leads to false-negative results and a consequent failure to detect possible contact sensitization.
In conclusion, and given the results of this study, we believe that patch testing with expired TRUE Tests® can give true-positive results; nevertheless, the reliability of each individual allergen reaction is open to question.
References 1 Bruze M, Conde-Salazar L, Goossens A, Kanerva L, White I R. Thoughts on sensitizers in a standard patch test series. The European Society of Contact Dermatitis. Contact Dermatitis 1999: 41: 241–250. 2 Fischer T, Kreilg¨ard B, Maibach H I. The true value of the TRUE test for allergic contact dermatitis. Curr Allergy Asthma Rep 2001: 1: 316–322.
382
3 Militello G, Woo D K, Kantor J, Egan C L, Solotoff S A, Spiers E M, Stierstorfer M B, James W D. The utility of the TRUE test in a private practice setting. Dermatitis 2006: 17: 77–84. 4 Jerajani H R, Melkote S. Thin-layer rapid-use epicutaneous test (TRUE test). Indian J Dermatol Venereol Leprol 2007: 73: 292–295.
5 Mose K F, Andersen K E, Christensen L P. Stability of selected volatile contact allergens in different patch test chambers under different storage conditions. Contact Dermatitis 2012: 66: 172–179. 6 Mowitz M, Zimerson E, Svedman C, Bruze M. Stability of fragrance patch test preparations applied in test chambers. Br J Dermatol 2012: 167: 822–827.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Contact Dermatitis, 70, 376–388
