home the book 3rd edition preface foreword table of contents how to use this book explanation of table 1 1 chemicals 2 abbreviations 3 groups of chemicals 4 products 5 photosensitivity 6 immediate contact... 7 patch test sensitization references previous editions about the author contact acdegroot publishing patchtesting.info

Table 3 Groups of Chemicals and Substances

Some textbooks on contact dermatitis not only provide recommendations for test concentrations and vehicles for individual chemicals, but also for groups of chemicals or substances. Such groups may consist either of chemically related compounds (e.g. sulfonamides, quaternary ammonium compounds), or functionally related chemicals or substances (e.g. pesticides, photographic chemicals, topical antihistamines).

Tables 3.1-3.4 provide an alphabetical listing of specific categories of such groups with test recommendations and references to their sources. With chemicals of some groups the risk of inducing patch test sensitization is greater than usual, and this is indicated by an *.

When a particular chemical to be patch tested is not included in Table 1, but does belong to one of the groups of chemicals or substances in Table 3, the investigator may thus have a first clue to determine a proper patch test concentration and vehicle for this chemical.

It should of course be appreciated that these test recommendations (especially for the groups of functionally related chemicals) can never be as precise for any particular chemical as those that were advised for individual chemicals.

The abbrevations used for the vehicles are as follows:

acet	=	acetone
alc	=	alcohol 70%
isoprop alc	=	isopropyl alcohol
MEK	=	methyl ethyl ketone
oo	=	olive oil
pet	=	petrolatum

Table 3.1 (Topical) drugs, antimicrobials and cosmetic ingredients

p-Aminobenzoic acid (PABA) esters	5% pet (1,2)
Antibiotics (topical)	10% pet (1)
Antihistamines (topical)	pure (1)
Antimycotics (topical)	pure and 25% pet (1)
Antimycotics, imidazoles	1% alc (8)
Barbiturates	10% alc or pet (8)
Benzodiazepines	5%-10% pet or aqua (8)
Benzotriazole derivatives	5% pet (7)
Beta-lactam antibiotics	1%-20% pet (8)
Carbowaxes (polyethylene glycols)	pure (1,2,6,8)
Cephalosporins	20% pet and pure (7); 1%-5% aqua (7);10%-20% pet (8);1%- 10% aqua (8)
Cinnamates	1% pet (6)
Essential oils	1% pet (1,2); 1% alc or 2% pet (6); 20% oo (10)
Gallate esters	0.1% and 1% pet or oo (5)
Halogenated salicylanilides	1% MEK (1,2)
Heparins	pure (8)
Oils of spices	5% alc (1)
Parabens	5% pet (1,2,6)
Penicillins	1%-20% pet (8)