Allergic contact dermatitis

Also known as Type IV, Delayed Hypersensitivity or Chemical Allergy

Only those persons who are genetically predisposed to specific chemical allergens are susceptible to experiencing an allergic response. In common with other allergies, repeated exposure to the specific allergen accelerates the sensitization process until that individual’s personal threshold is reached. Once this is achieved, subsequent exposure to the allergen will trigger a reaction. Depending on allergen exposure and the genetic profile of the individual, the process of sensitization may take days, weeks, months, years or never. In common with irritant contact dermatitis, it is important t distinguish between non-glove associated and glove-associated allergic contact dermatitis.

Non glove associated allergic contact dermatitis

With more than 2,800 substances having the potential to cause allergic contact dermatitis1)Drake L.A., Dorner W, Goltz R.W. (1995) “Guidelines of care for contact dermatitis” J Am Acad Dermatol 32:109-113, it is important to take a holistic view when trying to identify the source of any dermal reaction. Consideration should be given to soaps, detergents, lotions, jewelry, nickel, fragrances, glutaraldehyde, quaternary ammonias, formaldehyde and many other substances in the laboratory, home and outdoor environment.

Glove associated allergic contact dermatitis

The main agents responsible for glove-related allergic contact dermatitis are vulcanization accelerators (typically thiurams, thiazoles, carbamates etc), which are used routinely in the manufacture of natural rubber latex and nitrile gloves. However, other chemical contact sensitizers are plasticizers, stabilizers, antioxidants, biocides, preservatives, processing agents, donning agents, colorants etc. A more detailed list of chemical contact sensitizers is given in the table below:

List of chemical contact sensitizer

Accelerators:Plasticisers:Processing Agents:
Aldehydye-amineParatoluene sulfonamideSurfactants
Alkyphenol disulphidesPhthalates
BenzothiazolesNaphthylaminesStabilizers:
DithiocarbamatesDibutyl tin dilaurate
DithiophosphatesAntioxidants & antiozononants:Dibutyl tin maleate
GuanidinesAminesEpoxyresins
ThiroureaPhenols
ThiuramsSulphidesRetarders:
Thiocabamyl sulfenamidesPhosphitesPhthalic anhydride
MercaptobenzothiazolePPD seriesSulfonamide derivatives
ParaphenylenediamineN-nitrosodiphenylamine
Donning Agents:
Powders
Lubricants

More recently it has been discovered that allergic contact dermatitis can be derived from the latex itself, with Sommer2)Sommer, D.J. & Green C (2002) “Type IV hypersensitivity reactions to natural rubber latex: results of multi-centre study” Br. J. Dermatol Jan:146(1) pp114-117reporting a prevalence of less than 1% in a study covering 2738 patients.

Symptoms of allergic Chemical Allergy

Allergic contact dermatitis comes in various clinical forms, starting with an acute reaction (after an initial contact with the allergen) through to the chronic form (associated with persistent contact with the antigen). Symptoms at the early stage include redness, swelling, small blisters and itching. In its chronic form, these symptoms may be accompanied by dry, thickened skin, scaling, dryness, open lesions, development of papules etc. Typically the onset of symptoms is 6 to 48 hours3)Rietschel R.L., Fowler Jr JF, eds. (1995) Chapter 4: Histology of Contact Dermatitis Fisher’s Contact Dermatitis, 4th ed. Baltimore MD: Williams & Wilkins; 1995, 38-39.. Whilst differentiating allergic contact dermatitis from irritant contact dermatitis can be difficult, it is important to remember that whilst glove-associated irritant contact dermatitis is confined to the area of glove contact4)Cohen D.E. et al. (1998) “American Academy of Dermatology Position Paper on Latex Allergy” Journal of the American Academy of Dermatology. 39 (July): 98-106the symptoms of allergic contact dermatitis may extend up the arm beyond the area of glove contact.

Proposed action for managing Delayed Hypersensitivity

As diagnosis can be difficult, patch testing may be necessary. Here a range of allergens are used covering the most frequently encountered chemical contact sensitizers e.g. vulcanization accelerators. Often a sample of both sides of the suspect glove are used in the patch test. As powder can act as a vector for chemical allergens, it is important to recognize the potential benefit of having a powder-free policy with a view to limiting allergic contact dermatitis.

Other action that should be considered is as follows:

  • Consult occupational health and a dermatologist if symptoms persist.
  • Switch to gloves documented to be low in residual chemicals and low in chemical contact sensitizers.
  • Select powder-free gloves only.
  • Wear cotton or nylon glove liners, but be sure to replace them every time gloves are changed.
  • If a specific chemical allergen has been identified through patch testing, switch to a glove manufactured without this chemical.
  • Taking into account the likelihood of non glove-related causative agents, consider alternative allergen contact avenues e.g. the accelerator thiuram is found in fungicides and adhesive materials5)Taylor J.S., Leow Y.H. (2000) “Cutaneous Reactions to Rubber” Rubber Chemistry and Technology: Rubber Reviews. 73:3 July-August: 427-485.

As selecting gloves that are low in chemical contact sensitizers is important for limiting the risk of allergic contact dermatitis, request from the glove manufacturer high performance liquid chromatography (HPLC) or thin layer chromatography (TLC) test data to demonstrate that it was not possible to detect the most commonly used chemical contact sensitizers in the gloves. To aid in determining whether the gloves have low levels of residual chemicals, seek confirmation from the glove manufacturer that the glove have undergone sensitization testing e.g. Buehler Test or 200 Person Modified Draize Test.

References   [ + ]

1.Drake L.A., Dorner W, Goltz R.W. (1995) “Guidelines of care for contact dermatitis” J Am Acad Dermatol 32:109-113
2.Sommer, D.J. & Green C (2002) “Type IV hypersensitivity reactions to natural rubber latex: results of multi-centre study” Br. J. Dermatol Jan:146(1) pp114-117
3.Rietschel R.L., Fowler Jr JF, eds. (1995) Chapter 4: Histology of Contact Dermatitis Fisher’s Contact Dermatitis, 4th ed. Baltimore MD: Williams & Wilkins; 1995, 38-39.
4.Cohen D.E. et al. (1998) “American Academy of Dermatology Position Paper on Latex Allergy” Journal of the American Academy of Dermatology. 39 (July): 98-106
5.Taylor J.S., Leow Y.H. (2000) “Cutaneous Reactions to Rubber” Rubber Chemistry and Technology: Rubber Reviews. 73:3 July-August: 427-485

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