Commentary
THE AMERICAN ACADEMY OF DERMATOLOGY PATCH TEST SERIES EOR CONTACT DERMATITIS NORMAN B. KANOF, M.D., (Med.) Sc.D.
The patch test is essential for the definitive diagnosis and the competent management of allergic contact dermatitis. It can only be effectively studied by the accurate evaluation of this test. Despite the fact that the patch test does not duplicate the multiple applications, sweating and maceration of clinical exposure, it is safer and quicker for the identification of allergic contact dermatitis than trial and error or avoidance and re-exposure. Reliable in vitro tests may eventually be developed for this type of hypersitivity, but today the patch test is indispensable for proving the cause and directing the treatment of this frequently encountered clinical problem. The patch test is so well known that the term is widely used by the public. The basic principles on which the patch test are based are simple, and the execution of the test seems straightforward. Nonetheless, training and experience in the performance and interpretation of the test are necessary if the results obtained are to be valid. Patch tests have frequently been performed by persons lacking this necessary background, and the errors that have resulted have tarnished the image of the procedure, so that many dermatologists came to doubt the value of the patch test in their practices.
From the Department of Dermatology, New York University School of Medicine, New York, New York
A high proportion of cases of allergic contact dermatitis, perhaps as much as 80%, are caused by a small number of ubiquitous contactants, widely used chemicals to which much of the population is exposed.'' ^ A group of such chemicals (allergens) that have proved to be frequent causes of allergic contact dermatitis constitute a "standard," "screening" or "basic" patch test series or battery. Screening Tray Patch testing with such a standard series never supplants testing with suspected environmental agents, but testing with such a series is of great value when allergic contact dermatitis is suspected, and the cause is not revealed by careful history. It is not true that patch tests will only confirm what is obvious to the careful observer. Testing with a standard series produces as many unexpected as expected positive reactions.' An unexpected positive patch test may be the missing link that makes it possible for the dermatologist to establish the connection between the patient's environment and his disease. An unexpected positive patch test does not prove that chemical to be the
Address for reprints: Norman B. Kanof, M.D., 580 Fifth Avenue, New York, NY 10036. 827
828 Table 1.
INTERNATIONAL JOURNAL OF DERMATOLOGY Revised Standard Test Series (1976)
Medicaments, preservatives and perfumes Neomycin sulfate 20% Ammoniated mercury 1% Thimerosal 0.1% Ethylenediamine dihydrochloride 1% Parabens (methyl, ethyl, propyl, butyl, and benzyl, 3% each) 15% Wood alcohols 30% Caine mixture 8% Balsam of Peru 25% Lanolin 100% Benzyl alcohol 5% Cinnamic alcohol 5% Ouaternium 15 2% Imidazolidinyl 2% Captan 1% Hydroxycitronellal 4% Metals Potassium dichromate 0.5% Nickel sulfate 2.5% Rubber chemicals Mercaptobenzothiazole mix 1% Mercaptobenzothiazole 1% (MBT) Thiuram mix 1% Naphthyl mix 1% Black Rubber p-Phenylenediamine mix 0.6% (P.P.D. mix, 0.6%) Cabra mix 3% Others Formaldehyde (in water) 2% p-Phenylenediamine 1% Epoxy resin 1 % p-tert.-Butylphenol 2% PCMX 1 %
December 1977
Vol. 16
Allergic contact sensitivity may cause, or be a complication of, many eczematous dermatoses that persist despite careful management. Patch testing can help resolve these problems by identifying substances to be avoided, and by helping to choose safe therapeutic agents. Properly performed and interpreted patch tests are "scientific proof" of the cause of a dermatitis and may have medicolegal significance. AAD The American Academy of Dermatology set out to assist its members in making patch testing a practical and useful office procedure. The Academy proposed to do this in several ways. Through the North American Contact Dermatitis Croup, a standard test tray has been devised and monitored and amended as experience dictated. The NACDC also prepared a booklet* which gives explicit instructions for doing patch tests and for their proper reading and interpretation, and discusses the significance of positive reactions to the standard tray allergens. The most recent (1976) revision of the standard test series is seen in Table 1. Distribution
cause of the patient's problem. The positive test may only be evidence of the skin's immunologic memory. But half of such unexpected reactions proved relevant; exposure to the allergen could be traced and related to the patient's dermatitis. Patch testing requires a commitment of effort from the practicing dermatologist, and negative tests are discouraging. If the dermatologist tests more, he will see many negatives; but his harvest of unexpected positives will also increase and, from those positives, the satisfaction of a difficult problem resolved.
Three editions of the test materials and booklet have been distributed — in 1974, 1975 and 1976. As the 1976 materials have a "shelf life" of 2 years, no new distribution is planned before 1978. More than 2500 kits were distributed in each of the 3 years. Only a small percentage (estimate— 600 trays) were actively used during the first year of distribution, ln the subsequent 2 distributions, a much larger number (estimate— 1200 trays) were actively used. During 1975, the last year for which figures are available, approximately 40% of those dermatologists queried used the kit 5 times or less, 20%
No. 10
PATCH TEST
6 to 10 times, and 40% more than 10 times. Now that the test materials and instructions of use are readily available, the primary factor limiting the use of the patch test tray appears to be the time required for the application of the tests. Many dermatologists questioned believed that they should be testing more patients, but that the procedure was time consuming. In the last 3 years, the usefulness of routine office patch testing with a standard tray to the practicing dermatologist has been documented by Jordan,^ Shelmire,^' Garcia^ and Lepine.*^ Lepine concludes, "Results obtained from studies such as those conducted by the NACDG do indeed provide information relevant to the practice of the average dermatologist. Patch test screening kits developed and modified according to the results of such investigators provide the practitioner with an efficient, up-to-date means
Kanof
829
of evaluating patients suspected of having an allergic contact dermatitis." References 1. Hjortb, N., et al.: Epidemiology of contact dermatitis. Transac. St. John's Hosp. Dermatol. Soc. 55:17, 1969. 2. Hjorth, N., and Eregert, S.: Contact Dermatitis. In Textbook of Dermatology. Edited by Rook, A., Wilkinson, D. S., and Ebling, E. J. G.: Oxford, Blackwell Sci., 1972, pp. 305-385. 3. Agrup, G., Dablquist, I., Fregert, S., and Rorsman, H.: Value of bistory and testing in suspected contact dermatitis. Arch. Dermatol. 101:212, 1970. 4. The Role of Patch Testing in Allergic Contact Dermatitis. Richmond, Nortb American Contact Dermatitis Group, 1976. 5. Jordan, W. P., Jr.: Allergic contact dermatitis in band eczema. Arcb. Dermatol. 110:567, 1974. 6. Sbelmire, D.: Screening Patch Tests. Cutis 16:633, 1975. 7. Garcia, R. L.: Air Force experience witb routine patcb test screening, j . Assn. Milit. Dermatol. 2:62, 1976. 8. Lepine, E. M.: Results of routine office patch testing. Contact Dermatitis 2:89, 1976.
Cataract Surgery
Cataract is the commonest cause of blindness; and cataract removal is said to be the oldest operation in the history of surgery, ln the early days, this was achieved simply by knocking it backwards with a needle thrust through the limbus, so that it fell to the bottom of the vitreous, and this operation of "couching," which dated from the third millennium B.C., is still performed extensively, albeit damagingly, in remoter areas of the underdeveloped world. But, since 1748, "extraction" of the cataract gradually became the accepted method: the eyeball was incised along with the corneoscleral junction, and the opaque lens was lifted out. Until the 1940s it was thought safer to remove only the opaque lens nucleus; but nowadays the lens is nearly always removed complete with its tenuous capsule (an "intracapsular extraction") through a wider incision involving nearly the half-circumference of the corneo-scleral margin. The actual extraction has been rendered much simpler by the use of a freezing probe; this grips a frozen segment of the lens substance, whereas the traditional forceps can grasp only its very thin and friable capsule. And the operation has become much safer with the advent of ultrafine needles and suture materials (10.0 nylon or 8.0 "virgin" silk) which can close the wound so securely that the patients are now allowed out of bed the day after operation, and can leave hospital a few days later. — Lancet 2:612, 1976.
THE AMERICAN ACADEMY OF DERMATOLOGY PATCH TEST SERIES EOR CONTACT DERMATITIS NORMAN B. KANOF, M.D., (Med.) Sc.D.
The patch test is essential for the definitive diagnosis and the competent management of allergic contact dermatitis. It can only be effectively studied by the accurate evaluation of this test. Despite the fact that the patch test does not duplicate the multiple applications, sweating and maceration of clinical exposure, it is safer and quicker for the identification of allergic contact dermatitis than trial and error or avoidance and re-exposure. Reliable in vitro tests may eventually be developed for this type of hypersitivity, but today the patch test is indispensable for proving the cause and directing the treatment of this frequently encountered clinical problem. The patch test is so well known that the term is widely used by the public. The basic principles on which the patch test are based are simple, and the execution of the test seems straightforward. Nonetheless, training and experience in the performance and interpretation of the test are necessary if the results obtained are to be valid. Patch tests have frequently been performed by persons lacking this necessary background, and the errors that have resulted have tarnished the image of the procedure, so that many dermatologists came to doubt the value of the patch test in their practices.
From the Department of Dermatology, New York University School of Medicine, New York, New York
A high proportion of cases of allergic contact dermatitis, perhaps as much as 80%, are caused by a small number of ubiquitous contactants, widely used chemicals to which much of the population is exposed.'' ^ A group of such chemicals (allergens) that have proved to be frequent causes of allergic contact dermatitis constitute a "standard," "screening" or "basic" patch test series or battery. Screening Tray Patch testing with such a standard series never supplants testing with suspected environmental agents, but testing with such a series is of great value when allergic contact dermatitis is suspected, and the cause is not revealed by careful history. It is not true that patch tests will only confirm what is obvious to the careful observer. Testing with a standard series produces as many unexpected as expected positive reactions.' An unexpected positive patch test may be the missing link that makes it possible for the dermatologist to establish the connection between the patient's environment and his disease. An unexpected positive patch test does not prove that chemical to be the
Address for reprints: Norman B. Kanof, M.D., 580 Fifth Avenue, New York, NY 10036. 827
828 Table 1.
INTERNATIONAL JOURNAL OF DERMATOLOGY Revised Standard Test Series (1976)
Medicaments, preservatives and perfumes Neomycin sulfate 20% Ammoniated mercury 1% Thimerosal 0.1% Ethylenediamine dihydrochloride 1% Parabens (methyl, ethyl, propyl, butyl, and benzyl, 3% each) 15% Wood alcohols 30% Caine mixture 8% Balsam of Peru 25% Lanolin 100% Benzyl alcohol 5% Cinnamic alcohol 5% Ouaternium 15 2% Imidazolidinyl 2% Captan 1% Hydroxycitronellal 4% Metals Potassium dichromate 0.5% Nickel sulfate 2.5% Rubber chemicals Mercaptobenzothiazole mix 1% Mercaptobenzothiazole 1% (MBT) Thiuram mix 1% Naphthyl mix 1% Black Rubber p-Phenylenediamine mix 0.6% (P.P.D. mix, 0.6%) Cabra mix 3% Others Formaldehyde (in water) 2% p-Phenylenediamine 1% Epoxy resin 1 % p-tert.-Butylphenol 2% PCMX 1 %
December 1977
Vol. 16
Allergic contact sensitivity may cause, or be a complication of, many eczematous dermatoses that persist despite careful management. Patch testing can help resolve these problems by identifying substances to be avoided, and by helping to choose safe therapeutic agents. Properly performed and interpreted patch tests are "scientific proof" of the cause of a dermatitis and may have medicolegal significance. AAD The American Academy of Dermatology set out to assist its members in making patch testing a practical and useful office procedure. The Academy proposed to do this in several ways. Through the North American Contact Dermatitis Croup, a standard test tray has been devised and monitored and amended as experience dictated. The NACDC also prepared a booklet* which gives explicit instructions for doing patch tests and for their proper reading and interpretation, and discusses the significance of positive reactions to the standard tray allergens. The most recent (1976) revision of the standard test series is seen in Table 1. Distribution
cause of the patient's problem. The positive test may only be evidence of the skin's immunologic memory. But half of such unexpected reactions proved relevant; exposure to the allergen could be traced and related to the patient's dermatitis. Patch testing requires a commitment of effort from the practicing dermatologist, and negative tests are discouraging. If the dermatologist tests more, he will see many negatives; but his harvest of unexpected positives will also increase and, from those positives, the satisfaction of a difficult problem resolved.
Three editions of the test materials and booklet have been distributed — in 1974, 1975 and 1976. As the 1976 materials have a "shelf life" of 2 years, no new distribution is planned before 1978. More than 2500 kits were distributed in each of the 3 years. Only a small percentage (estimate— 600 trays) were actively used during the first year of distribution, ln the subsequent 2 distributions, a much larger number (estimate— 1200 trays) were actively used. During 1975, the last year for which figures are available, approximately 40% of those dermatologists queried used the kit 5 times or less, 20%
No. 10
PATCH TEST
6 to 10 times, and 40% more than 10 times. Now that the test materials and instructions of use are readily available, the primary factor limiting the use of the patch test tray appears to be the time required for the application of the tests. Many dermatologists questioned believed that they should be testing more patients, but that the procedure was time consuming. In the last 3 years, the usefulness of routine office patch testing with a standard tray to the practicing dermatologist has been documented by Jordan,^ Shelmire,^' Garcia^ and Lepine.*^ Lepine concludes, "Results obtained from studies such as those conducted by the NACDG do indeed provide information relevant to the practice of the average dermatologist. Patch test screening kits developed and modified according to the results of such investigators provide the practitioner with an efficient, up-to-date means
Kanof
829
of evaluating patients suspected of having an allergic contact dermatitis." References 1. Hjortb, N., et al.: Epidemiology of contact dermatitis. Transac. St. John's Hosp. Dermatol. Soc. 55:17, 1969. 2. Hjorth, N., and Eregert, S.: Contact Dermatitis. In Textbook of Dermatology. Edited by Rook, A., Wilkinson, D. S., and Ebling, E. J. G.: Oxford, Blackwell Sci., 1972, pp. 305-385. 3. Agrup, G., Dablquist, I., Fregert, S., and Rorsman, H.: Value of bistory and testing in suspected contact dermatitis. Arch. Dermatol. 101:212, 1970. 4. The Role of Patch Testing in Allergic Contact Dermatitis. Richmond, Nortb American Contact Dermatitis Group, 1976. 5. Jordan, W. P., Jr.: Allergic contact dermatitis in band eczema. Arcb. Dermatol. 110:567, 1974. 6. Sbelmire, D.: Screening Patch Tests. Cutis 16:633, 1975. 7. Garcia, R. L.: Air Force experience witb routine patcb test screening, j . Assn. Milit. Dermatol. 2:62, 1976. 8. Lepine, E. M.: Results of routine office patch testing. Contact Dermatitis 2:89, 1976.
Cataract Surgery
Cataract is the commonest cause of blindness; and cataract removal is said to be the oldest operation in the history of surgery, ln the early days, this was achieved simply by knocking it backwards with a needle thrust through the limbus, so that it fell to the bottom of the vitreous, and this operation of "couching," which dated from the third millennium B.C., is still performed extensively, albeit damagingly, in remoter areas of the underdeveloped world. But, since 1748, "extraction" of the cataract gradually became the accepted method: the eyeball was incised along with the corneoscleral junction, and the opaque lens was lifted out. Until the 1940s it was thought safer to remove only the opaque lens nucleus; but nowadays the lens is nearly always removed complete with its tenuous capsule (an "intracapsular extraction") through a wider incision involving nearly the half-circumference of the corneo-scleral margin. The actual extraction has been rendered much simpler by the use of a freezing probe; this grips a frozen segment of the lens substance, whereas the traditional forceps can grasp only its very thin and friable capsule. And the operation has become much safer with the advent of ultrafine needles and suture materials (10.0 nylon or 8.0 "virgin" silk) which can close the wound so securely that the patients are now allowed out of bed the day after operation, and can leave hospital a few days later. — Lancet 2:612, 1976.
