I have a patient with intermittent urticarial eruptions at work. He works in a factory manufacturing fluorescent dyes. I have reviewed the Material Safety Data Sheets for all of the chemicals used in the production, and I have found a possible culprit, an epoxy resin: 1,2-epoxy-3phenoxy propane (chem. family - glycidyl esthers). Now, I would like to confirm my impression with an allergy test, and I need help devising a skin test protocol for the above mentioned substance.

I have seen two reports of epoxy resin allergy which relied on a 20 minute patch test with an undiluted epoxy in a Finn Chamber. Is this the way to go with my patient as well? Glycidyl esthers are known to be corrosive to skin, and I want to make sure that no harm is done. Thanks.

Thank you for your inquiry.

There are several ways that you might consider to detect urticarial sensitivity to epoxy resins. I have copied below abstracts of articles illustrating these procedures. The strategies you might employ are:

1. You could proceed with the procedure that you mentioned. In all probability this would be safe.

2. As you know, epoxy resins are available as standard patch tests. There is a link (copied below) to the True Test patch test for epoxy resins, and if you were concerned you could apply a patch test for an hour and see if that was sufficient to elicit a positive immediate reaction.

3. Prick tests have been described to epoxy resins. Abstracts to the articles detailing the methods used are copied below. This is, however, a more complex procedure and would require some preparation of the resin beforehand.

4. You could test with a protocol used for patch testing which consists of epoxy resin 1% in acetone or petrolatum. You would apply the mixture for 20 to 30 minutes and then read.

I think any one of the above methods would be unlikely to be harmful, and all could possibly detect sensitivity to this agent.

Thank you again for your inquiry and we hope this response is helpful to you.

Standard patch testing with test epoxy resin material 1% in acetone or petrolatum

Allergy. 2002 Dec;57(12):1205-7.
Occupational contact urticaria from diglycidyl ether of bisphenol A epoxy resin.
Kanerva L, Pelttari M, Jolanki R, Alanko K, Estlander T, Suhonen R.
Section of Dermatology, Finnish Institute of Occupational Health, Helsinki, Finland.
Background: Epoxy resin (ER) is a common cause of occupational allergic contact dermatitis (ACD), but contact urticaria from ER is very rare.
Methods and Results: A plastic-product worker first developed ACD from diglycidyl ether of bisphenol A (DGEBA) epoxy resin, and subsequent exposure resulted half a year later in contact urticaria: first with edema of the lips and eyelids, and later an urticarial reaction on the upper chest, with strong swelling of the eyelids and tightness of the throat. The diagnosis was based on a positive skin prick test to his "own" ER compound, a positive prick test reaction to DGEBA, and a positive skin provocation test with the ER compound and DGEBA. The contact urticaria test reaction was strongly aggravated when the allergen was wiped off with an alcohol solution, apparently because the solution enhanced the penetration of the allergen.
Conclusions: Our case is of interest, first, because contact urticaria from ER is very rare, and second, because this is the second report in which a strongly intensified contact urticaria reaction was provoked by an alcohol solution. We suggest that if the contact urticaria provocation test with low-molecular-weight chemicals is negative, a contact urticaria provocation test with alcohol (CUPTA) should be performed.

Scand J Work Environ Health. 1991 Jun;17(3):208-15.
Immediate and delayed allergy from epoxy resins based on diglycidyl ether of bisphenol A.
Kanerva L, Jolanki R, Tupasela O, Halmepuro L, Keskinen H, Estlander T, Sysilampi ML.
Institute of Occupational Health, Helsinki, Finland.
This case report presents two patients with immediate and delayed allergy to epoxy resins based on diglycidyl ether of bisphenol A (DGEBA). In patch testing, the epoxy resin (DGEBA-based) of the standard series gave allergic reactions. Both patients had a prick test reaction of histamine size or larger to the human serum albumin (HSA) conjugate of DGEBA-based epoxy resins. One had been occupationally exposed to methyl tetrahydrophthalic anhydride (MTHPA) and had a histamine-size prick test reaction to the HSA conjugate of MTHPA; the other did not react to the conjugate. Determinations of specific immunoglobulin E were carried out with HSA-DGEBA conjugates, two DGEBA-based epoxy resins, and phthalic anhydrides. The first patient had positive tests to DGEBA, the DGEBA-based epoxy resins, and two phthalic anhydrides, and the second to DGEBA and the DGEBA-based epoxy resins, but not to the phthalic anhydrides.

Acta Derm Venereol Suppl (Stockh). 1987;134:90-4.
Occupational contact dermatitis and contact urticaria caused by epoxy resins.
Jolanki R, Estlander T, Kanerva L.
Institute of Occupational Health, Section of Dermatology, Helsinki, Finland.
Over a ten-year period (1974-1983) 542 cases of allergic occupational contact dermatitis were diagnosed in our clinic. Epoxy resins caused 71 cases (13.1%) of occupational allergic contact dermatitis (CD), and three cases (0.6%) of irritant CD. One contact urticaria was caused by an epoxy resin hardener, methyl hexahydrophthalic anhydride. Epicutaneous testing with standard epoxy resin 1% in pet. (mainly oligomer of molecular weight 340) produced allergic reactions in all the patients with allergic CD with the exception of three. These three patients had allergic reactions only to their own resins. Testing the 71 patients of allergic CD with epoxy hardeners produced allergic reactions in 19 (26.8%). None of the patients had separate delayed contact allergy to epoxy hardeners without simultaneous contact allergy to standard epoxy resin.

Phil Lieberman, M.D.
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