Allergic reactions to rubber can be due to allergy to natural latex sap or to one of the many chemicals used in the manufacturing of rubber. The types of chemicals used in the manufacturing of rubber include:
Accelerators
Activators
Antidegradants (antioxidants, antiozonants)
Vulcanizing agents
Retarders
Reinforcing agents
Fillers
Pigments
Processing aids
Blowing agents
Allergy can probably occur to any of these chemicals, although rubber accelerators seem to cause the greatest problems.
Contact allergy to rubber accelerators
Positive patch test to thiuram
Rubber dermatitis
Patch tests
Rubber dermatitis
What are rubber accelerators?
Rubber accelerators are chemicals used to speed up the manufacturing process of rubber (vulcanisation). This process makes untreated natural rubber latex suitable for use in the manufacture of many rubber products. There are many types of rubber accelerators in use but those listed below cause most cases of rubber contact dermatitis:
Chemical
Formula
CAS number
Benzothiazoles
2-Mercaptobenzothiazole
N-cyclohexyl-2-benzothiazolesulfenamide
Dibenzothiazyl disulfide
Morpholinylmercaptobenzothiazole
C7H5NS2
C13H16N2S2
C14H8N2S4
C11H12N2S20
149-30-4
95-33-0
120-78-5
102-77-2
Carba chemicals
Zinc diethyldithiocarbamate
Zinc dibutyldithiocarbamate
Diphenylguanidine
C10H20N2S4Zn
C18H36N2S4Zn
C13H13N3
14324-55-1
136-23-2
102-06-7
Thiurams
Tetramethylthiuram monosulfide
Tetramethylthiuram disulfide
Tetraethylthiuram disulfide
Dipentamethylenethiuram disulfide
C6H12N2S3
C16H12N2S4
C10H20N2S4
(C5H10NCS3)2
97.74.5
137-26-8
97-77-8
120-54-7
Hexamethylenetetramine (methenamine)
(CH2)6N4
100-97-0
What products contain rubber accelerators?
Nearly all rubber compounds contain rubber accelerators. The list below shows the widespread use of rubber products that we may come into contact with daily:
Household/recreational rubber products
Anti-slip carpet backing
Balloons
Elastic bands
Garden hoses and gloves
Kitchen gloves
Pillows and mattresses
Rubber gloves
Rubber handled sports equipment, e.g. golf club and raquet tennis racquet handles
Rubber handles (e.g. bicycles, car steering wheel)
Veterinary products, e.g. flea and tick sprays/powders
It is often difficult to know which rubber product contains which rubber accelerants. Often the manufacturer of the product will not know either.
What are the reactions to rubber accelerators?
The rash is known as allergic contact dermatitis. It can occur in many areas and in any of several patterns. The following table describes some of the common areas where rubber accelerator allergy may occur, the usual cause, and any distinguishing features of the allergy.
Location
Cause
Features
Hands
Rubber gloves
Rubber finger guards
Rubber handgrips
Oral Antabuse®
Rash caused by rubber gloves often distinguished by sharp cut-off at wrist
Rubber as a component of fabrics used in underwear such as girdles, bras and infant panties
Rubber in elasticated underwear
Rubber in upholstered furniture
Rubber carpet underlay
Rash localised to areas of contact with the garment
Rubber infant panties may produce an occlusive, macerating and irritating rash in the diaper area
Elbow rash has occurred from padded arms of furniture
How did I become allergic to rubber accelerators?
Chronic exposure is a likely reason. Surgeons, nurses, dentists, hairdressers and others who wear rubber gloves for work purposes can often develop sensitivity to natural rubber latex and rubber accelerators. In these cases allergy to rubber may come as a consequence of trying to protect your hands from other allergens.
Am I allergic to rubber accelerators?
Allergy to rubber accelerators is diagnosed by the clinical history and by special allergy tests, patch tests. These tests may identify which specific rubber accelerators you have an allergy to.
Thiuram mix tests four thiuram chemicals with one test. One of these four will cause about 9 out of 10 cases of allergy to thiuram mix. Similarly, mercapto mix tests for 3 chemicals in the one test.
You can self-test a rubber product for allergy, but this should only be done only after first talking with your dermatologist. Do this only with articles that are designed to stay on the skin, such as underwear or shoes. Initially, allow the article to be in contact with your skin of your forearm for a short period of time, say 1 hour. For the next 4 days look for any reaction. If no reaction occurs slowly lengthen the period of contact with your skin to a maximum of 48 hours.
Do not test insecticides or other chemical products in this way.
What should I do to avoid rubber accelerator allergy?
The best way to avoid rubber accelerator allergy is by being aware of products that contain rubber accelerators. However, it is generally difficult to determine which products contain rubber accelerators and which don't.
Minimize your exposure to all rubber products. Use alternative products made of vinyl, plastic, wood, leather or fabric. Even though some rubber gloves are labelled 'hypoallergenic' it is wise to contact the manufacturer to determine if they contain any of the rubber accelerators you are allergic to. Vinyl gloves may be a suitable alternative although some people are allergic to both rubber and vinyl. Tactylon® gloves are a good alternative for most people. Be aware that some non-rubber gloves provide less protection against viruses and certain chemicals than rubber gloves. Discuss the requirements of your gloves with your supplier/manufacturer.
If you are sensitive to rubber accelerators and undergoing dental work or surgery, you should inform your dentist or doctor so they can either use alternative gloves that are free of rubber accelerators, or patch test you in advance with the gloves they plan to use.
Avoid shoes made with rubber accelerators. Test shoes by wearing them for a few days and watch for a rash (shoe dermatitis) or have shoes patch tested. Any socks or stockings that have been worn with shoes that cause an allergy may become contaminated with rubber. These should not be worn again, as even washing may not remove the contaminant.
Non-rubber condoms (e.g. Durex Avanti) and plastic diaphragms may be suitable contraceptive alternatives. Cover padded arms of upholstered furniture with a towel and avoid walking barefoot on rubber-underlayed carpets.
Tricks to minimise contact with earloops of face masks include using paperclips or hospital wristbands to hold the earloops behind the head.
Treatment of rubber accelerator allergy
Treatment of the rash caused by rubber accelerators is with medications that are used to treat acutedermatitis/eczema.
Shoe dermatitis needs to be properly diagnosed and treated. Contact dermatitis of the feet can often become infected with Staphylococcus aureus (it can also be confused with the fungal infection, tinea pedis). Acute dermatitis can be treated with wet dressings of Burrow's solution or dilute vinegar. Short courses of systemic corticosteroids may speed up healing. Chronic shoe dermatitis may need to be managed with prolonged treatment of topical corticosteroids and/or coal tar and emollients. It is essential that you wear shoes free of the causative allergens.
Bothra A, Das S, Singh M, Pawar M, Maheswari A. Retroauricular dermatitis with vehement use of ear loop face masks during COVID-19 pandemic. J Eur Acad Dermatol Venereol. 2020;34(10):e549-52. doi:10.1111/jdv.16692 Journal