Fragrance Additives that Trigger Allergic Reactions: Study

Fragrance allergies can manifest clinically either as an immediate or a delayed-type reaction. Researchers have now identified those fragrance additives most likely to cause either immediate or delayed allergic reactions.  Fragrances can be absorbed into the body via the epidermis (skin), the lungs or the gastrointestinal tract. Because of this easy entry into the body, fragrance allergies are actually common in the general population.

Study overview

To determine the prevalence of immediate or delayed reaction to fragrance, the researchers enrolled 291 patients from the contact dermatitis clinic at King Chulalongkorn Memorial Hospital in Bangkok in a prospective study for allergic contact dermatitis, 205 of whom were women.  The enrolled 291 patients were given standard patch tests for allergic contact dermatitis. Those with positive reactions were then asked to undergo additional patch tests to assess both immediate and delayed reactions to 28 different fragrance substances.

Results overview

Cinnamic aldehyde and cinnamic alcohol were the most frequently encountered substances in positive immediate reactions and standard (delayed) patch test reactions. Immediate patch reactions to benzyl alcohol, sorbic acid, and coumarin were more frequently observed than standard patch test reactions.

The most common allergic reactions to standard patch test screening included fragrance mix I (19.59%), nickel sulfate (15.46%), methylisothiazolinone (10.65%), methyldibromo glutaronitrile (9.27%), balsam of Peru (8.25%), formaldehyde (8.25%) and fragrance mix II (8.25%).

Among the enrolled patients, 82 developed positive patch test reactions to one or more of the most common fragrance screening markers, particularly fragrance mix I (n = 57), balsam of Peru (n = 24), fragrance mix II (n = 24) and colophony (n = 21).

Additionally, the researchers found that a greater proportion of those who did vs. did not develop a positive patch test reaction to fragrance screening markers were women, aged older than 40 years and had hand dermatitis.

Secondary study overview

The researchers then enrolled 40 of the original patients who tested positive for at least one fragrance screening marker into an analysis for delayed patch testing with 28 individual fragrance allergens. Thirty-eight of those patients had a positive reaction, nearly half for an immediate reaction and most (86%) for a delayed patch test.

Secondary results overview

The additives with the highest rate of positive immediate reactions included cinnamic aldehyde (40%), cinnamic alcohol (27.5%), sorbic acid (20%), coumarin (17.5%) and geraniol (12.5%).*

The additives with the highest rate of positive delayed reactions included cinnamic alcohol (60%), cinnamic aldehyde (55%), ylang ylang oil (32.5%), balsam of Peru (30%) and isoeugenol (25%).*

*Fragrance substances are major components of spices and essential oils that are frequently used in a variety of Asian foods, beverages and personal care products such as mouthwash. 

Other personal care products with high levels of fragrances


  • Perfumes and colognes
  • Lipsticks
  • Toothpastes
  • Concealers
  • Eye shadows
  • Shampoos
  • Conditioners
  • Soaps
  • Lotions

assorted cosmetic products

What can you do?

If you have allergic reactions to chemical fragrances avoidance is the best policy. Here are some strategies experts say you can use to avoid fragrances:

  • Do not get fooled by “unscented”. These products may actually still contain a fragrance to make them unscented. Try to look specifically for products that say “fragrance-free.”
  • Read labels. As always, reading labels is a good way to make sure the product you are using does not contain fragrances.  Here are some to look out for:
    • Balsam of Peru
    • Cinnamic alcohol
    • Coumarin
    • Eugenol
    • Farnesol
    • Lyral
    • Oak moss absolute

source | source

Journal reference: NutchayaAmornruk, MD, et al. The immediate patch test reaction to fragrance in patients with allergic contact dermatitis to fragrance: A prospective study,Journal of the American Academy of Dermatology, June 9, 2022. Study abstract.