How to use this book

'Patch Testing' 4th Edition contains information on patch test concentrations and vehicles for defined chemicals, mixtures of defined chemicals, plant-derived substances, products, and groups of either chemically or functionally related substances and chemicals, as published in literature. In addition, data are provided which may directly or indirectly influence decision making relevant to patch test procedures and which enable the investigator to easily locate more detailed information. Thus, for every chemical it is indicated whether or not:

  • it is monographed in the Merck Index Online database (www.rsc.org/merck-index)
  • it is monographed in the Personal Care Products Council On-Line INFOBASE (a members only subscription database, www.personalcarecouncil.org) (previously: the CTFA Cosmetic Ingredient Dictionary and Handbook of the Cosmetic, Toiletry and Fragrance Association, Inc.)
  • it has caused photosensitivity reactions (for an alphabetical listing see Table 5)
  • it has caused immediate contact reactions (contact urticaria) (for an alphabetical listing see Table 6)
  • it has caused patch test sensitization (for an alphabetical listing see Table 7)
  • it is available as patch test material from commercial suppliers: Chemotechnique Diagnostics (www.chemotechnique.se), SmartPractice CANADA (www.smartpracticecanada.com, formerly Allergeaze and Brial) and SmartPractice EUROPE (www.smartpracticeeurope.com, formerly Trolab)

The sources of the data presented here are:

  • the major textbooks on contact dermatitis, including the most recent editions of 'Contact Dermatitis' (Springer-Verlag, 5th Edition, 2011), ‘Kanerva’s Occupational Dermatology’ (Springer-Verlag, 2nd Edition, 2012) and 'Fisher's Contact Dermatitis' (BC Decker, 6th Edition, 2008)
  • the monographs on fragrance raw materials, published by the Research Institute for Fragrance Materials (RIFM, www.rifm.org)
  • all editions of the journal 'Contact Dermatitis' from its onset in 1975 to March 2018, all editions of the journal 'The American Journal of Contact Dermatitis' and its successor 'Dermatitis' from its onset in 1990 up to March 2018
  • the Merck Index Online database
  • the Personal Care Products Council On-Line INFOBASE (which can be accessed by members of the American Contact Dermatitis Society)
  • CosIng, the European Commission database for information on cosmetic substances and ingredients (http://ec.europa.eu/growth/tools-databases/cosing)
  • the websites of the commercial suppliers of patch test materials (see above)
  • various sources on the internet, especially chemical databases for looking up CAS numbers, checking the correct nomenclature of chemicals and trying to identify unfamiliar chemicals and correct names of compounds which have been misspelled in literature. Useful databases included the PubChem Project (pubchem.ncbi.nlm.nih.gov/), ChemIDplus (https://chem.nlm.nih.gov/chemidplus/), The Good Scents Company Information System (thegoodscentscompany.com, for fragrance materials), ChemSpider (www.chemspider.com), Chemical Book (www.chemicalbook.com), Chemindustry.com (www.chemindustry.com) and dye|World dye variety (http://www.worlddyevariety.com/, for colouring materials)

The four main sections of this book are:

Table 1 This table contains information on published test concentrations and vehicles for defined chemicals, mixtures of defined chemicals, plant products (extracts, essential oils etc.) and other (more or less defined) compounds which have been used or may be used for patch testing

Table 2 This table is an alphabetical listing of abbreviations, and provides full chemical names and/or entry-names as used in Table 1

Table 3 This table contains information on test concentrations and vehicles for groups of either chemically or functionally related chemicals / substances

Table 4 This table contains information on test concentrations and vehicles for products

Choosing a test concentration and vehicle

For the test concentration of defined chemicals, mixtures of chemicals and plant products, Table 1 should be consulted first. If a particular chemical is not found under the name that is known to, or preferred by, the investigator, synonyms/other names of this compound, if available, should be looked up in the table (for the choice of the nomenclature see 'Explanation of Table 1').

When the chemical has been traced in the table, it is sometimes not difficult to decide on a test concentration and vehicle, as often only one concentration is given. Where two or more test options are given which differ considerably, we have tried to make a recommendation on the basis of an assessment of literature data. When such test advice could not be provided (which unfortunately is true in the vast majority of cases because of the lack of reliable scientific data), the investigator has to decide on a test concentration/vehicle him/herself by examining the various options shown. The following observations may then be of some help:

  • the column 'comments' sometimes refers to irritant reactions at certain concentrations and risk of patch test sensitization
  • the test recommendations of Dr Cronin (ref 5) seem to indicate a cautious approach; not infrequently she advised two test concentrations, the higher of which being slightly irritant
  • for 'new' allergens, it is often mentioned if and how many controls have been tested to exclude irritancy of the material used for patch testing and the results of such control testing

If the chemical to be tested is not shown in Table 1, Table 3 may provide a clue for testing by a published recommendation for the group of chemicals to which the compound under study belongs. For test concentrations of products, Table 4 should be consulted.