Allergic Contact Dermatitis


Allergens are responsible for only about 25% of occupational contact dermatitis.

75 % Irritant Contact Dermatitis

25 % Allergic Contact Dermatitis


Recognizing allergic causes is important because it makes possible effective treatment and prevention.

Allergic contact dermatitis (ACD) is a delayed type IV or cell-mediated hypersensitivity. The diagnosis of ACD is confirmed with patch testing. [LaDou, p. 283-5]

The following two tables illustrate some of the more common occupational contact allergens and the occupations most commonly affected by them. The occupations listed generally have the highest incidence rates of both allergic and irritant contact dermatitis.


Workers at Increased Risk for Allergic Contact Dermatitis: Table 1

Chromium: Cr
Nickel: Ni
Epoxy Resins: Epx
Acrylate Resins: Acr
Formaldehyde Resins: FmR
Rubber Chemicals: Rub
Formaldehyde: Frm
Glutaraldehyde: Glu
Colophony: Col
p-Phenylenediamine: pPD
Glycerol Thioglycolate: GTG
Kathon CG: KCG
  Cr Ni Epx Acr FmR Rub Frm Glu Col pPD GTG KCG
Cement Workers x   x     x            
Electricians     x           x      
House Painters         x       x     x
Shoemakers         x x            
Aircraft Assemblers     x   x              
Medical Workers       x   x x x        
Dental Workers     x x x x   x        
Textile Workers x x x   x x x     x    
Electronics Workers   x x x x       x      
Mechanics x x x     x     x x    
Printers x   x x x         x   x
Hairdressers   x       x       x x x
Housekeeping   x       x x x       x
Machinists   x         x   x     x


Source of Information in Tables

The two tables are based on Chapter 15, "Occupations Commonly Associated with Contact Dermatitis" in Marks & DeLeo, plus additions based on recent published reports indexed in Medline.


Workers at Increased Risk for Allergic Contact Dermatitis: Table 2

Benzoyl Peroxide: BP
Cinnamic Aldehyde: Cin
Garlic & Onions: Gar
Sesquiterpenes: Ses
Tuliposide A: Tul
Carbamates: Car
Fungicides: Fun
Poison Ivy: Ivy
Pine Dust & Tar: Pin
2Creosote: Cre
  BP Cin Urt Gar Ses Tul Car Fun Ivy Pin Cre
Bakers x x x                
Food Workers     x x              
Florists         x x          
Farm workers     x       x x x    
Roofers                     x
Carpenters                   x x

1Contact urticaria is an immediate, type 1, antibody-mediated hypersensitivity. It appears within minutes of contact and disappears within a few hours.

2Creosote is different from the other chemicals listed in that it causes a photoirritant contact dermatitis. There are also several foods that can cause this type of reaction, including lime, celery, parsnip and fig.

Other occupations with exposures to skin sensitizers: Morticians and embalmers (formaldehyde, glutaraldehyde and rubber chemicals); Foundry workers (formaldehyde, isocyanates and amines); Welders (colophony flux, chromium and nickel); Photo processors (Metol, thiourea, CD-2,CD-3, CD-4, formaldehyde, phenidone, phenols and amines)


Patch Testing

"The accuracy of the diagnosis depends on the experience , knowledge and skill level of the physician who makes the diagnosis, and on the difficulties in confirming the relationship with an exposure." Patch testing is only about 70% sensitive and 50% specific. A specificity of 50% means that in only 1/2 of the cases can a chemical inducing a positive patch test be established as the cause of the worker's dermatitis. [Kanerva  2004, p. 4]

Suppliers of Patch Test Allergens for Physicians

1. T.R.U.E. Test
2. Chemotechnique
3.Trolab patch test allergens are imported and distributed by:
Omniderm Inc.
997 Seguin
Hudson, Quebec Canada J0P 1H0
Tel: (514) 458-0158
4. The Hermal standardized screening patch-test kit is designed to be used with Finn Chambers:
Allerderm Laboratories
1330 Redwood Way Ste. C 
Petaluma, CA  94954 



Important Factors in Glove Selection:

  1. The glove polymer that minimizes permeation of the chemicals being handled;
  2. The glove thickness that maximizes durability and also provides dexterity and comfort;
Web sites of glove manufacturers who offer technical support:
Ansell chemsafe
Best Manufacturing Company

ACD: Chemicals ACD: Biologicals Contact Urticaria OA and ACD: Drugs

  Revised May 30, 2018

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