Reproducibility of patch tests

Journal of the American Academy of Dermatology

Smith et ai.

21. 22. 23. 24. 25. 26.

antitrypsin) in the regulation of immunologic and inflammatory reactions. Aust N Z J Moo 1980;10:449-53. Breit SN, Wakefield D, Robinson JP, et aJ. The role of alantitrypsin deficiency in the pathogenesis of immune disorders. CUn ImmunolImmunopathol 1985;35:363-80. Fulton RJ, Hart DA. Detection and partial characterization of lymphoid cell surface proteases. Cell Immunol 1980;55:394-405. Crovato F, Rebora A. Alphal-antitrypsin deficiency [Letter]. Arch Dermatol 1977;113:236. Hayem A, Scharfman A, Laine A, et al. Proteases and antiproteases in bronchoalveolar lavage. Bull Eur Physiopathol Respir 1980;16(suppl):247-58. Arora PK, Miller HC, Aronson LD. ai-Antitrypsin is an effector of immunological stasis. Nature 1978;274:589-90. Vischer TL. Protease inhibitors reduce mitogen induced lymphocyte stimulation. Immunology 1979;36:811-3.

27. Kitagawa S, Takaku F, Sakamoto S. Serine protease inhibitors inhibit superoxide production by human polymorphonuclear leukocytes and monocytes stimulated by various surface active agents. FEBS Lett 1979;107:331-4. 28. Nagai K, Nakamura T, Koyama J. Characterization of macrophage proteases involved in the ingestion of antigenantibody complexes by the use of protease inhibitors. FEBS Lett 1978;92:299-302. 29. Goldstein BD, Witz G, Amoruso M, et al. Protease inhibitors antagonize the activation of polymorphonuclear leukocyte oxygen consumption. Biochem Biophys Res Commun 1979;88:854-60. 30. Musson RA, Becker EL. The role of an activatable esterase in immune-dependent phagocytosis by human neutrophils. J ImmunoI1977;118:1354-65.

Reproducibility of patch tests Rainer Gollhausen, MD, Bernhard Przybilla, MD, and Johannes Ring, MD, PhD

Munich, West Germany Patch tests with a series of 39 substances were performed in 41 patients on one side of the upper aspect of the back. Testing was repeated on the contralateral side ofthe back 1 week later (sequential testing). In 35 other patients, duplicate patch test series were simultaneously applied on both sides of the back (concomitant testing). Ifa positive reaction to a test substance was obtained at only one side of the back, the result was regarded as nonreproducible. Of all positive reactions, 40.0% were nonreproducible at sequential testing and 43.8% were nonreproducible at concomitant testing. Weakly positive reactions were far more often nonreproducible than stronger reactions. (J AM ACAD DERMATOL 1989;21:1196-202.)

The problem of false-positive or false-negative patch test results is still a matter of controversy. 1, 2 Some authors blame concomitant testing of a large number of substances as the cause of multiple falsepositive test results ("angry back syndrome").3-6 A study that compared the retest of a standard patch test battery of 26 substances with the retest of only one to three substances, however, indicated that positive reactions were more often lost when retesting involved the total test battery. 7 Because few From the Dermatologische Klinik und Poliklinik der Ludwig-Maximilians-Universitiit. Presented in part at the XVII Congressus Mundi Dermatologiae, Berlin,May 24-29,1987. Accepted for publication Jan. 9, 1989. Reprint requests: Dr. Rainer Gollhausen, Derrnatologische Klinik und Poliklinik der Ludwig-Maximilians-Univcrsitat, Frauenlobstrasse 911, D·8000 Munich 2, Federal Republic of Germany. 16/1/10678

1196

studies have addressed the problem of reproducibility of patch testing, the following investigation was undertaken.

PATIENTS AND METHODS Seventy-six patients (21 women, 55 men; 19 to 86 years of age) participated after giving informed consent. They were referred for patch testing at least 3 weeks after any dermatitis had subsided. The skin of the upper part of the back was free of any sign of irritation. No patient was receiving corticosteroid treatment. Patch tests with a series of39 substances (Table!) were performed on the upper part ofthe back. Substances were applied to the skin in Finn Chambers (Epitest Ltd Oy, Hyryla, Finland) on Scanpor surgical tape (Norgesplaster, Oslo, Norway) for 2 days. Semiquantitative readings were made 2 and 3 days later by the method of Bandmann and Dohn. 8 Table II defines reaction scores used in this study. Only reactions exhibiting at least an infiltrated erythema (one-plus reaction) were regarded as positive.

Volume 21 Number 6 December 1989

Reproducibility ofpatch tests 1197

Table I. Test substances Standard series

Balsam of Peru Benzocaine Caine mix Cobalt chloride Epoxy resins Ethylenediamine Eucerin anhydride Formaldehyde Fragrance mix Gentamicin sulfate Iodochlorhydroxyquin Lanolin alcohol Mafenide Mercapto mix Mercuric chloride Naphthyl mix Neomycin sulfate Nickel sulfate Parabenmix Petrolatum PPD Phenylmercuric borate Potassium dichromate PPD mix Rosin Thiuram mix Turpentine

Concentration (%)

25

5 7 1 1 1 100

2 8

20

5

30 10

1 0.1 1

Ointment battery

Concentration (% )

Adeps suillus Cetylpyridinium chloride Glyceryl monostearate

100 0.5

100

Hydroquinone Alcohol cetylstearylicus emulsificans (Lanette N) Pentachlorophenol Polyethylene glycol 400 Polyethylene glycol 1500 Polyethylene glycol 4000 Sorbic acid Tincture of benzoin Triethanolamine

1 10.0

0.5

100

100

100

2.5

10

0.5

20

5 15

100 1 0.025

0.5 0.6

20 1

0.3

PPD, p·Phenylonediamine.

Sequential testing Patch tests were performed on one side of the upper partofthe back in 41 patients. One week later, testing was repeated on the contralateral side of the back. When a positive reaction was obtained in only one of the tests, the result was regarded as nonreproducible.

Table II. Scores used in evaluation of patch test results* Score

rR

(+)

Concomitant testing

+

In 35 patients the patch test series was applied simultaneously to each side of the back. Otherwise the method was as previously described herein.

+++

RESULTS Sequential testing Of 41 patients, 24 had at least one positive reaction in one of the tests. There were a total of 70 positive reactions; the average and the standard deviation of positive results per person were 1. 7 ± 2.3. When differences in the grade of reactivity were disregarded, only seven patients had identical patch test results for both tests (Fig. 1).

++

++++

Reaction

No visible reaction Irritative reaction Erythema Infiltrated erythema Infiltrated erythema with scattered papules and vesicles Infiltrated erythema with dense papules and vesicles Bullous reaction

*Reference 8.

Twenty-one patients had 55 positive reactions in the first test, whereas 22 patients exhibited 57 positive results when testing was repeated. At the second test, 13 positive reactions to the first test were lost, and 15 new positive results were gained. Thus 28 of 70 reactions (40.0%) were found to be positive

Journal of the American Academy of Dermatology

1198 Gollhausen et al. n

41

17 patients with no positive reaction at both tests 7 patients with reproducible reactions at both tests

:.:. ....

17 patients with at least one non reproducible reaction at either test

Fig. 1. Sequential testing. Graphic representation of patients with positive reactions.

n = 55

III

100

l: 0

.; ; u

10

aI l..

80

aI

> -;;

'iii

60

0

~

'i5

.

aI

40

en

1'1

l: aI

u

l.. aI

20

~

........ .........•...•.. .............•... .:.:.:.:.:-:.:.:. ..........•...••. ::::::::::::::::: :.:.:.::::::::::: ....... .... .... . ........•....••.. :::::::::::::.::: ..........•....•. ::::::::::::::::: .............•..• ................. ..:.:.:.:.:.:.:.:. ...........•...• :::::::::::::::: ...............

~:

n

13

1st test

n = 57

·............... ........ .. ':':':':':':'.' ................ ··............... .............. . .............. ...... ............... ','

............. ·::::::::::::::: ............. . ............ ............. ............... ................. . .. .. .. .. .. .. ::::::::::::::: ................ ·::::::::::::::: .... . '.'

.............. n

= 15

2nd test

n

= 70

·· ... ·................. ................ :.:.:.:.:.:.:.:. .·...•............... .:-:.:.:.:.:.:.:

o .

.:::::::::::::::: . ...... ...... ::.:::::::::::::

·.:.:.:.:.:. :.:.: n

positive reactions only at one test positive reactions at both tests

28

either 1st or 2nd test

Fig. 2. Sequential testing. Graph shows nonreproducible positive test reactions.

in only one of both tests (Fig. 2). There was a random distribution of nonreproducible results among various allergens (Table III). One-plus reactions, however, were far less reproducible than two- or three-plus reactions. Of 31 one-plus reactions, 21 (68%) were nonreproducible compared with 7 of 31 two- or three-plus reactions (23%) (p < 0.001) (Fig. 3). Eight reactions that changed from one-plus in one test to two- or three-plus in the other were not considered in this comparison. Concomitant testing

Of 35 patients, 17 had at least one positive reaction in one of the test series. There were a total of 32 positive reactions; the average and the standard de-

viation of positive results were 0.9 ± 1.2. Eight patients had identical patch test results on both sides of the upper part of the back (Fig. 4). Of 32 reactions, 14 (43.8%) were positive in only one of the test series. One-plus reactions tended to be less reproducible than stronger reactions, but the difference was not statistically significant (Fig. 5). DISCUSSION

Our results indicate a low reproducibility ofpatch test results, especially for weakly positive reactions. There was a random distribution ofnonreproducible results among various allergens (Tables III and IV). A similar tendency can be found in other studies. 9-22

Volume 21 Number 6 December 1989

Reproducibility ofpatch tests 1199

n

100 In

C 0

'';:;

u

. 111

80

Q)

> '"

'';:;

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· . ................ ................ ·................ . ................ ·1_'· •••••••.. ·............... . . ::............... ··:::::::::::::... ··............... · .. . · 1'-.- • • • • •

60

0

ll.

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= 70

LJO

Q)

I

I.

••••••• ••••• I •

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p

< 0.001

···................ ·· ...... ······ ...... ·· ... "

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........ ...... :.:.:.:.:. ........... .•.............. .:::::::::::::::: ................... . ::::::::::::::::: ::::::::::::::::: .:.:.:.:.:.:.:.:. ::::::::::::::::: ................. ::::::::::::::::: ::::::::::::::::: . .... .

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positive reactions only at one test positive reactions at both tests

• • • • • • iI • •

III

.

= 31

. . ..................

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...c

n

20

Q)

n == 28

ll.

all positive reactions

n

= 21

n

=7

++ I +++ I ++++ reactions

of-

reactions

Fig. 3. Sequential testing. Graph illustrates that one-plus reactions are less reproducible than strong positive reactions. (Eight reactions were omitted in the partition of weakly and strongly positive reactions because they were one-plus at one and more than one-plus at the other test.)

n

35

O ~ ~

~

E::::1

18 patients with no positive reactions at both tests 8 patients with reproducible reactions at both tests 9 patients with at least one non repro· ducible reactions at either test

Fig. 4. Concomitant testing. Graphic representation of patients with positive reactions. Fischer and Rystedt9 found a relatively high number offalse-positive reactions in patch tests with metals. Fischer and Maibach10 noted obvious variations in the composition of patch test allergens in petrolatum. Prott 11 found that 54% of patch test reactions in patients retested for medicolegal assessments were nonreproducible. He considered them to be falsepositive results and blamed the outcome on excessively high test concentrations and testing during an active state of dermatitis. In a review of the persistence of allergic contact

sensitivity, Keczkes et al. 12 reported a high percentage ofpositive reactions (3% to 74%, mean 30%) lost to retesting. Dooms-Goossens et alP noticed a 37% decrease in positive reactions on retesting after 3 to 25 months; only 36% of patients exhibited concordant positive results. These authors suggested that possible causes might have been allergen avoidance and retesting ofpatients when the dermatitis was less active. They did not consider the problem of reproducibility, however~ Agrup 14 retested 379 hand eczema patients with 11 substances. Only 164 of 304 positive reactions (53.9%) were positive with either

1200

Journal of the American Academy of Dermatology

Gollhausen et aJ.

Table Ill. Sequential tests: Allergens yielding positive results Allergen

Standard series

Balsam of Peru Benzocaine Caine mix Cobalt chloride Ethylenediamine Eucerin anhydride Fragrance mix Gentamicin sulfate Lanolin alcohol Mafenide Mercuric chloride Naphthyl mix Neomycin sulfate Nickel sulfate ParaOOn mix PPD

Phenylmercuric borate Potassium dichromate PPD mix Rosin

Thiuram mix Total

Ointment battery

Adeps suillus Cetylpyridinium chloride Alcohol cetylstearylicus emulsmcans (Lanette N) Sorbic acid Tincture of benzoin Triethanolamine Total Total of standard series and ointment battery

Nonreproducible positive reactions/ AIl positive reactiOM

2/4 1/3 3/6 2/3 0/1 1/3 2/3 1/1 0/3 1/2 0/1 2/2 2/7 1/5 0/1 1/5

0/1 1/2 1/1 0/2

..2d1:23/58 1/3 1/2 1/2

0/1

1/3

J.LL 5/12

28/70

PPD, p-Phenylenediamine.

series. Retesting after a prolonged period, however, is not suitable to assess the reproducibility of patch testing,because the results obtained may depend on factors other than methods. A high frequency of discordant results has been found in testing with allergens supplied by different manufacturers. 15 In addition, comparisons of different patch test methods have yielded discordant results in 11%, 18%, and 33% of all positive reactions, respectively.16-18 With the concept of the "angry back syndrome"

Table IV. Concomitant tests: Allergens yielding positive results Allergen

Standard series

Balsam of Peru Benzocaine Caine mix Cobalt chloride Epoxy resin Fragrance mix Gentamicin sulfate Neomycin sulfate Nickel sulfate PPD PPDmix Rosin

Thiurammix Total

Ointment battery

Cetylpyridinium chloride Alcohol cetylstearylicus emulsificans (Lanette N) Polyethylene glycol 1500 Tincture of benzoin Total Total of standard series and ointment battery

Nonreproducible positive/ AIl positive reactions

1/3 0/1

0/1 0/1 1/1

0/1

2/3 0/3 2/4

1/1 1/1

0/1

~ 9/23

4/5

0/1

1/1 ~ ~

14/32

PPD, p-Phenylenediamine.

described by Mitchell,4 and the "excited skin syndrome" described by Maibach,19 some investigators 5,6, 19-22 focused on "false positive" reactions only. They blamed the concomitant testing of multiple substances as the cause of the high percentage (29% to 42%) of nonreproducible positive results (Table V), because they retested one patch at a time. Bandmann and Agathos23 reported a lower percentage (8.6%) of lost positive reactions than the investigators of the angry back syndrome. They performed the appropriate control study, that is, they retested not only one to three allergens at a time but also the entire series of 26 substances. With this method it was found that variability was in the same range in both tests. When the complete patch test series was repeated in 37 patients, 13 of 128 positive reactions were lost, but 23 new reactions occurred. Thus 36 of 151 positive reactions (24%) were nonreproducible. 7 Ifthe variability of patch test results is no greater in retesting with the entire standard tray than in

Volume 21 Number 6 December 1989

Reproducibility ofpatch tests 1201

n

III

c

100 •

.2

i L,

~

:~

80.

60.

~

Q.

40 -

=

32

.... ........ ··.···:-:.:.:.:.:.:.: ·................. .. ................ ......•......... · . ................ ................ ................ ·:::::::::::::::: · ..

n

= 19

n.s.

= 11

n

.. .. .~:~:~:~:~:~:~:~ :::::::::::::::: . . .::::::::::::::: . .

D ...... ......

positive reactions only at one test positive reactions at both tests

20 n = 14

all positive reactions

n

= 11

+ reactions

n

= 3

++/+++/++++ reactions

Fig. 5. Concomitant testing: nonreproducible positive test reactions. (Two reactions were omitted in the partition of weakly and strongly positive reactions because they were one-plus at one and more than one-plus at the other test.)

retesting with only one to three allergens, concomitant testing ofmultiple substances cannot beblamed for a high number of false-positive reactions. Furthermore, in other studies, we found no evidence to support the concept of the angry back syndrome, that is, a single strongly positive reaction can induce a generalized hyperirritability of the skin).24 Thus the concept of false-negative test results should be reevaluated. rhe low reproducibility of patch testing demonstrated in several studies3-s cannot be explained by concomitant testing of multiple substances but, rather, is inherent in the method. Therefore retesting only compounds that have previously been found to caUSe a positive reaction will yield an inappropriate impression, because false-positive as well as false-negative results can occur. For example, patients with a clear-cut history of contact dermatitis caused by nickel may have negative results of a patch test.25,26 The problem ofthe "silentbacksyndrome," that is, offalse-negative patch test results, is perhaps underestimated. 24 Reactions lost at retesting should not be regarded as false-positive without further assessment. Skin hyperreactivity and hyporeactivity may contribute to the unsatisfactory reproducibility of patch test results. These phenomena, however, are not well understood. 27 ,28 In any case, to avoid "status eCzematicus," the investigator must ensure that active

Table V. Studies of the "angry back syndrome": Positive reactions lost to retesting Positive reactions lost (%)

Investigator

Mitchell4 Maibach et al. 2o Bruynzeel et a1. 21 Luderschmidt et al. 22 Bandmann and Agathos 23

35

56

61

11 40

42.0 29.0 44.0 30.0

8.6

dermatitis is not present at the time of patch testing.26,29 Magnusson and Hersle30 reported a high incidence of false-positive reactions because of a nonspecific increase in skin reactivity induced by irritating test materials. In our study we endeavored to avoid "status eczematicus" and did not observe skin irritation induced by the tape. The low reproducibility of patch test reactions emphasizes the importance of the use of medical history to check the relevance of each positive reaction and to account for the possibility of false-negative results.!' 8 Ifimportant consequences, such as medicolegal considerations or· a change of profession, may result from patch testing, duplicate patch testing should be performed and, ifnecessary, a provocative test considered. 6 The repeated open application test31 may be useful, although false-positive

1202 Gollhausen et al. reactions from irritating substances such as formaldehyde may occur (unpublished data). The newly designed "iterative patch test" improves reliability of patch testing for weakly positive results. 32 REFERENCES 1. Fischer T, ~aibach HI. Patch testing in allergic contact dermatItIS: an upda teo Semin Dermatol1986'5:21424. ' 2. Rycroft RJG. False reactions to nonstandard patch tests. Semin DermatoI1986;5:225-30. 3. Mitchell JC. The angry back syndrome: eczema creates eczema. Contact Dermatitis 1975;1:193-4. 4. Mitchell JC. Multiple concomitant positive patch test reactions. Contact Dermatitis 1977;3:315-20. 5. Bruynzeel DP. Angry back or excited skin syndrome [Thesis]. Kripps Repro Mette1 Amsterdam, 1983. 6. Bruynzeel DP. Maibach HI. Excited skin syndrome (angry back). Arch Dermatol 1986; I22:323-8. 7. Bandmann HJ, Agathos M. Das "Angry Back Syndrom." Untersuchungsergebnisse mit Sequenztestungen, Wiederholungstestungen und dem Cocarden-(Target-)Test. Hautarzt 1981:32(supp15);97-104. 8. Bandrnann HJ, Dohn W. Die Epikutantestung. Munich: Bergmann, 1967. 9. Fischer T, Rystedt I. False-positive, follicular and irritant patch test reactions to metal salts. Contact Dermatitis 1985;12:93-8. 10. Fischer T, Maibach H. Patch test allergens in petrolatum: a reappraisal. Contact Dermatitis 1984;11:224-8. 11. Pratt FJ. Zur Beweiskraft epikutaner Tests. Dtsch Dermatol 1986;34:129-30. 12. Keczkes K, Basheer AM, Wyatt BH. The persistence of allergic contact sensitivity; a lO-year follow-up in 100 patients. Br J Dermatol 1982;107:461-5. 13. Doo~-Goossens A, Degref H, Parijs M, et al. A retrospective study of patch test results from 163 patients with stasis dermatitis or leg ulcers. Derroatologica 1979'159: 231-L ' 14. Agrup G. Hand eczema and other hand dermatoses in south Sweden. Acta Derm Venereal (Stockh) 1969;(suppl 61)49:14,66-71,80-5. 15. Kleinhans D, Burg G, Krieg Th, et aI. Sind Epikutantestbestecke verschiedener Hersteller miteinander vergleichbar? Hautarzt 1983;11:580-3.

Journal of the American Academy of Dermatology 16. Peltonen L. Comparison of AI-test and Finn chamber test. Contact Dermatitis 1981;7:192-6. 17. Cronin E. Comparison of AI-test and Finn chamber. Contact Dermatitis 1978;4:301-2. 18. Bruynzeel DP, Ducomhs G, Hannuksela M, et al. True test, European multicenter study. Contact Dermatitis 1988; 19:91-7. 19. Maibach HI. The E.S.S.-excited skin syndrome (alias the "angry back"). In: Ring J, Burg G, eds. New trends in allergy. Berlin: Springer-Verlag, 1981:208-21. 20. Maibach HI, Fregert S, Magnusson B, et al. Quantification of the excited skin syndrome (tbe "angry back"): retesting one patch at a time. Contact Dermatitis 1982;8:78. 21. BruynzeeI DP, van Ketel WG, von Blomberg-van der Flier M, et al. Angry back or the excited skin syndrome. J AM ACAD DERMATOL 1983;8:392-7. 22. Ludersehmidt C, Heilgemeier G, Ring J, et al. Polyvalente Kontaktallergie versus "Angry Back": Zur Problematik falsch positiver Epikutantestreaktionen. Allergologie 1982; 5:262-4. 23. Bandmann HJ, Agathos M. New results and Some remarks to the "angry back syndrome". Contact Dermatitis 1981' 7:23-6. ' 24. Kligman AM, Gollhausen R. The "angry back": a new concept or old confusion? Br J DermatoI1986;115(suppl 31);93-100. 25. Moller H,.Svensso~ A; Metal sensitivity: positive history but negatlve test mdlcates atopy. Contact Dermatitis 1986;14:57-60. 26. Podmore P, Burrows D, Bingham EA. Prediction of patch test results. Contact Dermatitis 1984;11:283-4. 27. Anderson KE, Benezra C, Burrows D et aI. Contact dermatitis: a review. Contact Dermatitis '1987;16:55-78. 28. von Blomberg M, Boerrigter GH, Scheper RJ. Interference of simultaneous skin tests in delayed hypersensitivity. Immunology 1978;35:361-7. 29. Wilson HTH. Standard patch tests in eczema and dermatitis. Br J DermatoI1955;67:291-8. 30. Magnusson B, Hersle K. Patch test methods. III.Influence of adhesive tape on test response. Acta Derm Venereal (Stockh) 1966;46:275-8. 31. Hannuksela M, Salo H. The repeated open application test (ROAT). Contact Dermatitis 1986;14:221-7. 32. Gollhausen R, Ring J, PrzybiUa B. Der iterative Test zur Unterscheidung kontaktallergischer oder irritativer Epikutantestreaktionen [AbstractJ. Allergologie 1987;10:427.