Contact Dermatitis

Contact Allergens

RESOURCES FOR CONTACT ALLERGENS

Safe Product Resources

BABY CLEANSERS 38413219

In the 50 best-selling baby cleansers, 94% of them had at least one of 10 total allergens that were identified in the cohort of products (full table HERE).
More than have the products contain cocamidopropyl betaine (72%), fragrance (64%), or sodium benzoate (54%).
These products made an average of ~11 claims per product, one of which was "hypoallergenic/allergy tested". Products with this claim were no less likely to contain allergens than products without this claim.
Claims that did correlate with a reduction in allergens include: "synthetic fragrance free" (2.2 vs 3.6 average allergens) and "National Eczema Association Seal of Acceptance (1.8 vs 3 average allergens).
The claim, "petrolatum free" was associated with an increased average number of allergens (5.3 vs 2.7).
There was an overall positive trend between number of marketing claims and number of allergens (more claims, more allergens), and slight trend towards more expensive products having fewer allergens.

FRAGRANCES (Cutis. 2024)

Fragrances are organic compounds that are volatile enough to produce an odor. There are natural (essential oils) and synthetic fragrances.
Fragrance molecules can act as allergens in 3 ways: haptens (combines directly with carrier protein), prehaptens (requires activation, ie via oxidation, before binding to carrier protein; linalool and limonene are examples of this), and prohaptens (require enzymatic reaction, ie in the skin itself).
The following are commonly test contact allergens that are frequently positive:
- fragrance mix 1
- fragrance mix 2
- balsam of peru (aka myroxylon pereirae resin)
- linalool hydroperoxides
- limonene hydroperoxides
There are 162 documented fragrance allergens, and 80 are essential oils. (27427818) (Figure)
Occupational fragrance allergies are common in hair dresser and beauticians, office workers (exposed to aromatherapy diffusers), and food handlers; those working with industrial or cleaning chemicals or metalworking may have exposures to masking fragrances at higher rates.
Up to 40% of fragrance allergies may be missed by testing fragrance mix 1/2 and balsam of peru only
It is recommended that those with possible or confirmed fragrance allergies avoid ALL fragrances, as 1 occult fragrance missed could be the difference between success and failure. Many fragrances are chemically related and can cross-react with each other.
Beware of misleading characterization of products:
- "Unscented" can mean the product had an odor that was masked with a masking fragrance
- "Fragrance free" can mean free of "artificial" fragrances, and thus contain many essential oils

Tips For Refractory Fragrance Contact Allergy

urge spouses and other close contacts to adhere to use of safe products
contact with pets that use fragranced shampoos can be implicated
heavily fragranced salon products and result in contact dermatitis that lasts weeks - bring you own shampoo and other skin care products!
passive transfer of fragrance from palms to face and in from airborn allergens can be a major source

European Directive Fragrances in Natural Products (24603515)

There are 26 fragrance ingredients identified as being known to cause contact allergy, many of which occur naturally.
- 8 synthetic: alpha-isomethyl ionone, amyl cinnamaldehyde (amyl cinnamal), amyl cinnamyl alcohol, benzyl cinnamate, butylphenyl methylpropional (lilial), hexyl cinnamaldehyde (hexyl cinnamal), hydroxyisohexyl-3-cyclohexene carboxaldehyde (Lyral), and methyl heptin carbonate
  - These are generally NOT a concern in natural products, but hexyl cinnamal can be used in fruit and honey flavorings, and amyl cinnamal in fruit and walnut flavorings (important for lip and systemic contact allergy)
- 18 natural, and the products they are found in (quick summary created with ChatGPT):
  - Cinnamic Aldehyde
    - Avoid:
      - Natural Products: Cinnamon, cassia, hyacinth, myrrh, rose, patchouli, Stereum subpileatum (fungus).
      - Foods: Citrus peel, tomato, anise, bay leaves, basil.
      - Commonly Found In: Sweets (chocolate, artificial fruit flavors), curry, condiments, pickles, pâté, perfumed teas, beer, wine, gin, vermouth, brandy, spiced liquors
  - Cinnamic Alcohol
    - Avoid:
      - Natural Products: Cinnamon, balsam of Peru, hyacinth, daffodil, benzoin.
      - Foods: Same as above.
  - Eugenol
    - Avoid:
      - Natural Products: Clove, cinnamon, basil, dill, lemon balm, nutmeg, bay leaves, vanilla, anise, oregano.
      - Commonly Found In: Topical products, clove oil, cinnamon leaf oil.
  - Isoeugenol
    - Avoid:
      - Natural Products: Ylang-ylang, sandalwood, jonquil, nutmeg, mace, basil, dill seed, gardenia.
      - Foods: Same as eugenol, including nonalcoholic drinks and baked goods.
  - Moss Allergens
    - Avoid:
      - Natural Products: Oakmoss absolute, tree moss.
      - Foods: Fruit, honey, and spice flavorings containing oakmoss.
  - Coumarin
    - Avoid:
      - Natural Products: Cassia cinnamon, tonka bean, vanilla grass, sweet woodruff, mullein, sweet grass, melilot, deer’s-tongue, sweet clover.
      - Commonly Found In: Topical products, some pipe tobaccos, and alcoholic drinks.
  - Limonene
    - Avoid:
      - Natural Products: Citrus fruits (especially orange), lemon oil, verbena, citronella, eucalyptus, lavender, rosemary, caraway, peppermint.
      - Foods: Nonalcoholic beverages, ice cream, candies, baked goods, gelatins, puddings, chewing gum.
  - Farnesol
    - Avoid:
      - Natural Products: Ylang-ylang, jasmine, rose oil, tolu balsam, cassia, musk ambrette, citronella, neroli, lemongrass, star anise, linden flower.
      - Commonly Found In: Topical products, cigarettes, potential exposure in lip products.
  - Citral
    - Avoid:
      - Natural Products: Lemon myrtle, lemongrass, lemon tea tree, may cheng, verbena, Melissa.
      - Commonly Found In: Citrus oils (lime, lemon, grapefruit, orange), ginger, peach, and many fruit flavorings.
  - Linalool
    - Avoid:
      - Natural Products: Ho leaf, bois de rose, coriander, linaloe, sweet basil, lavender, ylang-ylang, geranium oil.
      - Commonly Found In: Various fruits (e.g., peach, plum), mint and fruit flavorings.
  - Citronellol
    - Avoid:
      - Natural Products: Lemon eucalyptus, citronella grass, citrus fruits, rose, lemongrass, basil, eucalyptus, geranium, sandalwood.
      - Commonly Found In: Fruit and floral flavorings.
  - Geraniol
    - Avoid:
      - Natural Products: Rose, palmarosa, citronella, geranium, lemon.
      - Commonly Found In: Fruit flavorings (peach, raspberry, grapefruit, etc.).
  - Benzyl Alcohol
    - Avoid:
      - Natural Products: Found in fruits, teas, jasmine, hyacinth, ylang-ylang.
      - Commonly Found In: Fruit, nut, honey, vanilla flavorings.
  - Benzyl Salicylate
    - Avoid:
      - Natural Products: Some edible fruits, green tea, black tea.
      - Commonly Found In: Flavoring substances in foods and beverages
  - Hydroxycitronellal
    - Avoid:
      - Natural Products: Found in various essential oils (specific sources not detailed).
      - Commonly Found In: Additive in cigarettes.
  - Anisyl Alcohol
    - Avoid:
      - Natural Products: Vanilla pods, anise seed.
      - Commonly Found In: Additive in cigarettes.
  - Benzyl Benzoate
    - Avoid:
      - Natural Products: Kaempferia rotunda, Zingiber cassumunar, balsams (Tolu and Peru), tuberose flowers, hyacinth, Narcissus jonquilla, Dianthus caryophyllus, ylang-ylang.
      - Commonly Found In: Used as a flavoring agent in foods for its balsamic odor and taste.

Formaldehydes

Quaternium 15 alone captures 53% of patients with ACD to the formaldehyde group; adding the optimal second allergen (formaldehyde 1%) captures 78%; the optimal 5 top allergens capture >94% of patients. 38972480

ALCOHOLS

Propylene Glycol

A colorless, odorless, viscous liquid with low toxicity. Used as a solvent, vehicle, and humectant in many products. Found in all kinds of topical OTC and prescription products. Can cause a variety of reactions including allergic and irritant dermatitis, contact urticaria, and systemic contact dermatitis. 29923851

Lalla SC, Nguyen H, Chaudhry H, Killian JM, Drage LA, Davis MDP, Yiannias JA, Hall MR. Patch Testing to Propylene Glycol: The Mayo Clinic Experience. Dermatitis. 2018. PMID: 29923851.

MY SUMMARY: Tested 5, 10, and 20% concentrations. Overall reaction rate was 1.2% (0.85% allergic, 0.35% irritant). Rate was significantly higher with 20% concentration compared to lower concentrations for allergic contact dermatitis. Concentration did not impact irritant contact dermatitis.