Fragrance most common cause of cosmetic allergic contact dermatitis

Washington - Fragrances have been around for thousands of years, extracted from animals and plant components including leaves, stems bark, wood, roots, fruit seeds, gum and oleoresins.

Unfortunately, matching the positive aspects of these special and very different scents are the many allergic reactions that can go along with them in the allergy-predisposed individual.

Alison Ehrlich, M.D., M.H.S., associate clinical professor and director of clinical research of the department of dermatology at George Washington University, reviews the basics of fragrance allergies and the latest tests available to detect them.

Rash of signs, symptoms

Dr. Ehrlich explained that a fragrance allergy can present as a type IV allergic reaction, an immediate type I allergic reaction or as an overlap of types IV and I.

The allergic patient will commonly present with symptoms on the face, eyelids and neck, and less commonly with a hand dermatitis or widespread reaction.

"Symptoms of allergic contact dermatitis can include burning and itching. Acute ACD is frequently characterized by a vesicular eruption. Lichenified plaques or an acneform eruption can occur with chronic ACD, as well as hypersensitivity and ID reactions. The eruption occurs several hours to days after exposure and is usually due to a new formulation of a product that the patient has always used, or simply the use of a brand new product, causing an allergic reaction," Dr. Ehrlich tells Dermatology Times.

Sniffing out the culprits

Dr. Ehrlich says that there are three major test series used for the detection of fragrance allergy.

The first is T.R.U.E. TEST (Allerderm) and includes fragrance mix and balsam of Peru. The second is the North American Standard (NA-STD) series and includes cinnamic aldehyde, balsam of Peru, and fragrance mix (FM) I. The NA-STD now includes FM II, composite mix and sesquiterpene lactone mix, and now has an extended series containing ylang-ylang oil, benzyl alcohol, tea tree oil, Lyral (International Flavors and Fragrances) - an important sensitizer (also known as Kovanol) - and benzyl salicylate. The third test is the fragrance series.

Balsam of Peru is a very common constituent of medical, dental, food and cosmetic products on the market and is very often the cause of allergic reactions in patients, and is responsible for a slew of cross reactions. It is a vanilla- and cinnamon-scented aromatic liquid that comes from the Myroxolon balsamum tree, consisting of 60 percent to 70 percent cinnamein (a combination of cinnamic acid, cinnamyl cinnamate, benzyl benzoate, benzoic acid and vanillin), 30 to 40 percent of resins of unknown composition as well as essential oils similar to citrus fruit peel.

Fragrance mix is composed of oak moss absolute, isoeugenol and eugenol, cinnamic aldehyde and alcohol, geraniol, hydroxycitronellal and alpha-amyl cinnamic alcohol. Dr. Ehrlich says that positive reactions to this test can be seen in 5.5 percent to 11.4 percent of patients tested, with a detection rate of 70 percent to 80 percent.

Dr. Ehrlich says, "Oak moss absolute accounts for one-third of the fragrance mix I reactions. Yet, fragrance mix is not the perfect screener. Approximately 7 to 15 percent of relevant cases of fragrance allergy are not recognized by the fragrance mix."

Ideal timing

She notes that ideally, the initial reading of a patch test evaluation should be done at 48 hours with clearly marked sites, and a final reading at 96 hours. Interpretations of reactions should be graded as 0, 1, 2 and 3 strengths.

Dr. Ehrlich advised on how to effectively and correctly test a patient's cosmetic products. A "leave on" product should be applied twice a day for seven to 14 days to the inner aspect of the elbow. A "wash-off" product should be applied twice a day for seven to 14 days, and washed off five to 10 minutes after application.